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-revision 654 by ph10,
Tue Aug  2 11:00:40 2011 UTC
+revision 835 by ph10,
Wed Dec 28 16:10:09 2011 UTC
 Line 85 
 USER DOCUMENTATION
           pcrecpp           details of the C++ wrapper
           pcredemo          a demonstration C program that uses PCRE
           pcregrep          description of the pcregrep command
+          pcrejit           discussion of the just-in-time optimization support
+          pcrelimits        details of size and other limits
           pcrematching      discussion of the two matching algorithms
           pcrepartial       details of the partial matching facility
           pcrepattern       syntax and semantics of supported
-Line 96 
 USER DOCUMENTATION
+Line 98 
 USER DOCUMENTATION
           pcrestack         discussion of stack usage
           pcresyntax        quick syntax reference
           pcretest          description of the pcretest testing command
+          pcreunicode       discussion of Unicode and UTF-8 support
         In  addition,  in the "man" and HTML formats, there is a short page for
         each C library function, listing its arguments and results.
- LIMITATIONS
-        There are some size limitations in PCRE but it is hoped that they  will
-        never in practice be relevant.
-        The  maximum  length of a compiled pattern is 65539 (sic) bytes if PCRE
-        is compiled with the default internal linkage size of 2. If you want to
-        process  regular  expressions  that are truly enormous, you can compile
-        PCRE with an internal linkage size of 3 or 4 (see the  README  file  in
-        the  source  distribution and the pcrebuild documentation for details).
-        In these cases the limit is substantially larger.  However,  the  speed
-        of execution is slower.
-        All values in repeating quantifiers must be less than 65536.
-        There is no limit to the number of parenthesized subpatterns, but there
-        can be no more than 65535 capturing subpatterns.
-        The maximum length of name for a named subpattern is 32 characters, and
-        the maximum number of named subpatterns is 10000.
-        The  maximum  length of a subject string is the largest positive number
-        that an integer variable can hold. However, when using the  traditional
-        matching function, PCRE uses recursion to handle subpatterns and indef-
-        inite repetition.  This means that the available stack space may  limit
-        the size of a subject string that can be processed by certain patterns.
-        For a discussion of stack issues, see the pcrestack documentation.
- UTF-8 AND UNICODE PROPERTY SUPPORT
-        From release 3.3, PCRE has  had  some  support  for  character  strings
-        encoded  in the UTF-8 format. For release 4.0 this was greatly extended
-        to cover most common requirements, and in release 5.0  additional  sup-
-        port for Unicode general category properties was added.
-        In  order  process  UTF-8 strings, you must build PCRE to include UTF-8
-        support in the code, and, in addition,  you  must  call  pcre_compile()
-        with  the  PCRE_UTF8  option  flag,  or the pattern must start with the
-        sequence (*UTF8). When either of these is the case,  both  the  pattern
-        and  any  subject  strings  that  are matched against it are treated as
-        UTF-8 strings instead of strings of 1-byte characters.
-        If you compile PCRE with UTF-8 support, but do not use it at run  time,
-        the  library will be a bit bigger, but the additional run time overhead
-        is limited to testing the PCRE_UTF8 flag occasionally, so should not be
-        very big.
-        If PCRE is built with Unicode character property support (which implies
-        UTF-8 support), the escape sequences \p{..}, \P{..}, and  \X  are  sup-
-        ported.  The available properties that can be tested are limited to the
-        general category properties such as Lu for an upper case letter  or  Nd
-        for  a  decimal number, the Unicode script names such as Arabic or Han,
-        and the derived properties Any and L&. A full  list  is  given  in  the
-        pcrepattern documentation. Only the short names for properties are sup-
-        ported. For example, \p{L} matches a letter. Its Perl synonym,  \p{Let-
-        ter},  is  not  supported.   Furthermore,  in Perl, many properties may
-        optionally be prefixed by "Is", for compatibility with Perl  5.6.  PCRE
-        does not support this.
-    Validity of UTF-8 strings
-        When  you  set  the  PCRE_UTF8 flag, the strings passed as patterns and
-        subjects are (by default) checked for validity on entry to the relevant
-        functions.  From  release 7.3 of PCRE, the check is according the rules
-        of RFC 3629, which are themselves derived from the  Unicode  specifica-
-        tion.  Earlier  releases  of PCRE followed the rules of RFC 2279, which
-        allows the full range of 31-bit values (0 to 0x7FFFFFFF).  The  current
-        check allows only values in the range U+0 to U+10FFFF, excluding U+D800
-        to U+DFFF.
-        The excluded code points are the "Low Surrogate Area"  of  Unicode,  of
-        which  the Unicode Standard says this: "The Low Surrogate Area does not
-        contain any  character  assignments,  consequently  no  character  code
-        charts or namelists are provided for this area. Surrogates are reserved
-        for use with UTF-16 and then must be used in pairs."  The  code  points
-        that  are  encoded  by  UTF-16  pairs are available as independent code
-        points in the UTF-8 encoding. (In  other  words,  the  whole  surrogate
-        thing is a fudge for UTF-16 which unfortunately messes up UTF-8.)
-        If an invalid UTF-8 string is passed to PCRE, an error return is given.
-        At compile time, the only additional information is the offset  to  the
-        first byte of the failing character. The runtime functions (pcre_exec()
-        and pcre_dfa_exec()), pass back this information  as  well  as  a  more
-        detailed  reason  code if the caller has provided memory in which to do
-        this.
-        In some situations, you may already know that your strings  are  valid,
-        and  therefore  want  to  skip these checks in order to improve perfor-
-        mance. If you set the PCRE_NO_UTF8_CHECK flag at compile time or at run
-        time,  PCRE  assumes  that  the pattern or subject it is given (respec-
-        tively) contains only valid UTF-8 codes. In  this  case,  it  does  not
-        diagnose an invalid UTF-8 string.
-        If  you  pass  an  invalid UTF-8 string when PCRE_NO_UTF8_CHECK is set,
-        what happens depends on why the string is invalid. If the  string  con-
-        forms to the "old" definition of UTF-8 (RFC 2279), it is processed as a
-        string of characters in the range 0  to  0x7FFFFFFF.  In  other  words,
-        apart from the initial validity test, PCRE (when in UTF-8 mode) handles
-        strings according to the more liberal rules of RFC  2279.  However,  if
-        the  string does not even conform to RFC 2279, the result is undefined.
-        Your program may crash.
-        If you want to process strings  of  values  in  the  full  range  0  to
-x7FFFFFFF,  encoded in a UTF-8-like manner as per the old RFC, you can
-        set PCRE_NO_UTF8_CHECK to bypass the more restrictive test. However, in
-        this situation, you will have to apply your own validity check.
-    General comments about UTF-8 mode
-.  An  unbraced  hexadecimal  escape sequence (such as \xb3) matches a
-        two-byte UTF-8 character if the value is greater than 127.
-. Octal numbers up to \777 are recognized, and  match  two-byte  UTF-8
-        characters for values greater than \177.
-.  Repeat quantifiers apply to complete UTF-8 characters, not to indi-
-        vidual bytes, for example: \x{100}{3}.
-. The dot metacharacter matches one UTF-8 character instead of a  sin-
-        gle byte.
-.  The  escape sequence \C can be used to match a single byte in UTF-8
-        mode, but its use can lead to some strange effects.  This  facility  is
-        not available in the alternative matching function, pcre_dfa_exec().
-.  The  character escapes \b, \B, \d, \D, \s, \S, \w, and \W correctly
-        test characters of any code value, but, by default, the characters that
-        PCRE  recognizes  as digits, spaces, or word characters remain the same
-        set as before, all with values less than 256. This  remains  true  even
-        when  PCRE  is built to include Unicode property support, because to do
-        otherwise would slow down PCRE in many common cases. Note in particular
-        that this applies to \b and \B, because they are defined in terms of \w
-        and \W. If you really want to test for a wider sense of, say,  "digit",
-        you  can  use  explicit Unicode property tests such as \p{Nd}. Alterna-
-        tively, if you set the PCRE_UCP option,  the  way  that  the  character
-        escapes  work  is changed so that Unicode properties are used to deter-
-        mine which characters match. There are more details in the  section  on
-        generic character types in the pcrepattern documentation.
-.  Similarly,  characters that match the POSIX named character classes
-        are all low-valued characters, unless the PCRE_UCP option is set.
-. However, the horizontal and  vertical  whitespace  matching  escapes
-        (\h,  \H,  \v, and \V) do match all the appropriate Unicode characters,
-        whether or not PCRE_UCP is set.
-. Case-insensitive matching applies only to  characters  whose  values
-        are  less than 128, unless PCRE is built with Unicode property support.
-        Even when Unicode property support is available, PCRE  still  uses  its
-        own  character  tables when checking the case of low-valued characters,
-        so as not to degrade performance.  The Unicode property information  is
-        used only for characters with higher values. Furthermore, PCRE supports
-        case-insensitive matching only  when  there  is  a  one-to-one  mapping
-        between  a letter's cases. There are a small number of many-to-one map-
-        pings in Unicode; these are not supported by PCRE.
  AUTHOR
         Philip Hazel
-Line 272 
 AUTHOR
+Line 117 
 AUTHOR
  REVISION
-        Last updated: 07 May 2011
+        Last updated: 24 August 2011
         Copyright (c) 1997-2011 University of Cambridge.
  ------------------------------------------------------------------------------
-Line 372 
 UNICODE CHARACTER PROPERTY SUPPORT
+Line 217 
 UNICODE CHARACTER PROPERTY SUPPORT
         are supported. Details are given in the pcrepattern documentation.
+ JUST-IN-TIME COMPILER SUPPORT
+        Just-in-time compiler support is included in the build by specifying
+          --enable-jit
+        This  support  is available only for certain hardware architectures. If
+        this option is set for an  unsupported  architecture,  a  compile  time
+        error  occurs.   See  the pcrejit documentation for a discussion of JIT
+        usage. When JIT support is enabled, pcregrep automatically makes use of
+        it, unless you add
+          --disable-pcregrep-jit
+        to the "configure" command.
  CODE VALUE OF NEWLINE
         By  default,  PCRE interprets the linefeed (LF) character as indicating
-Line 619 
 AUTHOR
+Line 481 
 AUTHOR
  REVISION
-        Last updated: 02 August 2011
+        Last updated: 06 September 2011
         Copyright (c) 1997-2011 University of Cambridge.
  ------------------------------------------------------------------------------
-Line 835 
 NAME
+Line 697 
 NAME
         PCRE - Perl-compatible regular expressions
- PCRE NATIVE API
+ PCRE NATIVE API BASIC FUNCTIONS
         #include <pcre.h>
-Line 851 
 PCRE NATIVE API
+Line 713 
 PCRE NATIVE API
         pcre_extra *pcre_study(const pcre *code, int options,
              const char **errptr);
+        void pcre_free_study(pcre_extra *extra);
         int pcre_exec(const pcre *code, const pcre_extra *extra,
              const char *subject, int length, int startoffset,
              int options, int *ovector, int ovecsize);
+ PCRE NATIVE API AUXILIARY FUNCTIONS
+        pcre_jit_stack *pcre_jit_stack_alloc(int startsize, int maxsize);
+        void pcre_jit_stack_free(pcre_jit_stack *stack);
+        void pcre_assign_jit_stack(pcre_extra *extra,
+             pcre_jit_callback callback, void *data);
         int pcre_dfa_exec(const pcre *code, const pcre_extra *extra,
              const char *subject, int length, int startoffset,
              int options, int *ovector, int ovecsize,
-Line 904 
 PCRE NATIVE API
+Line 778 
 PCRE NATIVE API
         char *pcre_version(void);
+ PCRE NATIVE API INDIRECTED FUNCTIONS
         void *(*pcre_malloc)(size_t);
         void (*pcre_free)(void *);
-Line 919 
 PCRE API OVERVIEW
+Line 796 
 PCRE API OVERVIEW
         PCRE has its own native API, which is described in this document. There
         are also some wrapper functions that correspond to  the  POSIX  regular
-        expression  API.  These  are  described in the pcreposix documentation.
+        expression  API,  but they do not give access to all the functionality.
-        Both of these APIs define a set of C function calls. A C++  wrapper  is
+        They are described in the pcreposix documentation. Both of  these  APIs
-        distributed with PCRE. It is documented in the pcrecpp page.
+        define  a  set  of  C function calls. A C++ wrapper is also distributed
+        with PCRE. It is documented in the pcrecpp page.
-        The  native  API  C  function prototypes are defined in the header file
+        The native API C function prototypes are defined  in  the  header  file
-        pcre.h, and on Unix systems the library itself is called  libpcre.   It
+        pcre.h,  and  on Unix systems the library itself is called libpcre.  It
         can normally be accessed by adding -lpcre to the command for linking an
         application  that  uses  PCRE.  The  header  file  defines  the  macros
-        PCRE_MAJOR  and  PCRE_MINOR to contain the major and minor release num-
+        PCRE_MAJOR and PCRE_MINOR to contain the major and minor  release  num-
-        bers for the library.  Applications can use these  to  include  support
+        bers  for  the  library.  Applications can use these to include support
         for different releases of PCRE.
         In a Windows environment, if you want to statically link an application
-        program against a non-dll pcre.a  file,  you  must  define  PCRE_STATIC
+        program  against  a  non-dll  pcre.a  file, you must define PCRE_STATIC
-        before  including  pcre.h or pcrecpp.h, because otherwise the pcre_mal-
+        before including pcre.h or pcrecpp.h, because otherwise  the  pcre_mal-
         loc()   and   pcre_free()   exported   functions   will   be   declared
         __declspec(dllimport), with unwanted results.
-        The   functions   pcre_compile(),  pcre_compile2(),  pcre_study(),  and
+        The  functions  pcre_compile(),  pcre_compile2(),   pcre_study(),   and
-        pcre_exec() are used for compiling and matching regular expressions  in
+        pcre_exec()  are used for compiling and matching regular expressions in
-        a  Perl-compatible  manner. A sample program that demonstrates the sim-
+        a Perl-compatible manner. A sample program that demonstrates  the  sim-
-        plest way of using them is provided in the file  called  pcredemo.c  in
+        plest  way  of  using them is provided in the file called pcredemo.c in
         the PCRE source distribution. A listing of this program is given in the
-        pcredemo documentation, and the pcresample documentation describes  how
+        pcredemo  documentation, and the pcresample documentation describes how
         to compile and run it.
+        Just-in-time compiler support is an optional feature of PCRE  that  can
+        be built in appropriate hardware environments. It greatly speeds up the
+        matching performance of  many  patterns.  Simple  programs  can  easily
+        request  that  it  be  used  if available, by setting an option that is
+        ignored when it is not relevant. More complicated programs  might  need
+        to     make    use    of    the    functions    pcre_jit_stack_alloc(),
+        pcre_jit_stack_free(), and pcre_assign_jit_stack() in order to  control
+        the  JIT  code's  memory  usage.   These functions are discussed in the
+        pcrejit documentation.
         A second matching function, pcre_dfa_exec(), which is not Perl-compati-
-        ble, is also provided. This uses a different algorithm for  the  match-
+        ble,  is  also provided. This uses a different algorithm for the match-
-        ing.  The  alternative algorithm finds all possible matches (at a given
+        ing. The alternative algorithm finds all possible matches (at  a  given
-        point in the subject), and scans the subject just  once  (unless  there
+        point  in  the  subject), and scans the subject just once (unless there
-        are  lookbehind  assertions).  However,  this algorithm does not return
+        are lookbehind assertions). However, this  algorithm  does  not  return
-        captured substrings. A description of the two matching  algorithms  and
+        captured  substrings.  A description of the two matching algorithms and
-        their  advantages  and disadvantages is given in the pcrematching docu-
+        their advantages and disadvantages is given in the  pcrematching  docu-
         mentation.
-        In addition to the main compiling and  matching  functions,  there  are
+        In  addition  to  the  main compiling and matching functions, there are
         convenience functions for extracting captured substrings from a subject
         string that is matched by pcre_exec(). They are:
-Line 969 
 PCRE API OVERVIEW
+Line 857 
 PCRE API OVERVIEW
         pcre_free_substring() and pcre_free_substring_list() are also provided,
         to free the memory used for extracted strings.
-        The  function  pcre_maketables()  is  used  to build a set of character
+        The function pcre_maketables() is used to  build  a  set  of  character
-        tables  in  the  current  locale   for   passing   to   pcre_compile(),
+        tables   in   the   current   locale  for  passing  to  pcre_compile(),
-        pcre_exec(),  or  pcre_dfa_exec(). This is an optional facility that is
+        pcre_exec(), or pcre_dfa_exec(). This is an optional facility  that  is
-        provided for specialist use.  Most  commonly,  no  special  tables  are
+        provided  for  specialist  use.  Most  commonly,  no special tables are
-        passed,  in  which case internal tables that are generated when PCRE is
+        passed, in which case internal tables that are generated when  PCRE  is
         built are used.
-        The function pcre_fullinfo() is used to find out  information  about  a
+        The  function  pcre_fullinfo()  is used to find out information about a
-        compiled  pattern; pcre_info() is an obsolete version that returns only
+        compiled pattern; pcre_info() is an obsolete version that returns  only
-        some of the available information, but is retained for  backwards  com-
+        some  of  the available information, but is retained for backwards com-
-        patibility.   The function pcre_version() returns a pointer to a string
+        patibility.  The function pcre_version() returns a pointer to a  string
         containing the version of PCRE and its date of release.
-        The function pcre_refcount() maintains a  reference  count  in  a  data
+        The  function  pcre_refcount()  maintains  a  reference count in a data
-        block  containing  a compiled pattern. This is provided for the benefit
+        block containing a compiled pattern. This is provided for  the  benefit
         of object-oriented applications.
-        The global variables pcre_malloc and pcre_free  initially  contain  the
+        The  global  variables  pcre_malloc and pcre_free initially contain the
-        entry  points  of  the  standard malloc() and free() functions, respec-
+        entry points of the standard malloc()  and  free()  functions,  respec-
         tively. PCRE calls the memory management functions via these variables,
-        so  a  calling  program  can replace them if it wishes to intercept the
+        so a calling program can replace them if it  wishes  to  intercept  the
         calls. This should be done before calling any PCRE functions.
-        The global variables pcre_stack_malloc  and  pcre_stack_free  are  also
+        The  global  variables  pcre_stack_malloc  and pcre_stack_free are also
-        indirections  to  memory  management functions. These special functions
+        indirections to memory management functions.  These  special  functions
-        are used only when PCRE is compiled to use  the  heap  for  remembering
+        are  used  only  when  PCRE is compiled to use the heap for remembering
         data, instead of recursive function calls, when running the pcre_exec()
-        function. See the pcrebuild documentation for  details  of  how  to  do
+        function.  See  the  pcrebuild  documentation  for details of how to do
-        this.  It  is  a non-standard way of building PCRE, for use in environ-
+        this. It is a non-standard way of building PCRE, for  use  in  environ-
-        ments that have limited stacks. Because of the greater  use  of  memory
+        ments  that  have  limited stacks. Because of the greater use of memory
-        management,  it  runs  more  slowly. Separate functions are provided so
+        management, it runs more slowly. Separate  functions  are  provided  so
-        that special-purpose external code can be  used  for  this  case.  When
+        that  special-purpose  external  code  can  be used for this case. When
-        used,  these  functions  are always called in a stack-like manner (last
+        used, these functions are always called in a  stack-like  manner  (last
-        obtained, first freed), and always for memory blocks of the same  size.
+        obtained,  first freed), and always for memory blocks of the same size.
-        There  is  a discussion about PCRE's stack usage in the pcrestack docu-
+        There is a discussion about PCRE's stack usage in the  pcrestack  docu-
         mentation.
         The global variable pcre_callout initially contains NULL. It can be set
-        by  the  caller  to  a "callout" function, which PCRE will then call at
+        by the caller to a "callout" function, which PCRE  will  then  call  at
-        specified points during a matching operation. Details are given in  the
+        specified  points during a matching operation. Details are given in the
         pcrecallout documentation.
  NEWLINES
-        PCRE  supports five different conventions for indicating line breaks in
+        PCRE supports five different conventions for indicating line breaks  in
-        strings: a single CR (carriage return) character, a  single  LF  (line-
+        strings:  a  single  CR (carriage return) character, a single LF (line-
         feed) character, the two-character sequence CRLF, any of the three pre-
-        ceding, or any Unicode newline sequence. The Unicode newline  sequences
+        ceding,  or any Unicode newline sequence. The Unicode newline sequences
-        are  the  three just mentioned, plus the single characters VT (vertical
+        are the three just mentioned, plus the single characters  VT  (vertical
-        tab, U+000B), FF (formfeed, U+000C), NEL (next line, U+0085), LS  (line
+        tab,  U+000B), FF (formfeed, U+000C), NEL (next line, U+0085), LS (line
         separator, U+2028), and PS (paragraph separator, U+2029).
-        Each  of  the first three conventions is used by at least one operating
+        Each of the first three conventions is used by at least  one  operating
-        system as its standard newline sequence. When PCRE is built, a  default
+        system  as its standard newline sequence. When PCRE is built, a default
-        can  be  specified.  The default default is LF, which is the Unix stan-
+        can be specified.  The default default is LF, which is the  Unix  stan-
-        dard. When PCRE is run, the default can be overridden,  either  when  a
+        dard.  When  PCRE  is run, the default can be overridden, either when a
         pattern is compiled, or when it is matched.
         At compile time, the newline convention can be specified by the options
-        argument of pcre_compile(), or it can be specified by special  text  at
+        argument  of  pcre_compile(), or it can be specified by special text at
         the start of the pattern itself; this overrides any other settings. See
         the pcrepattern page for details of the special character sequences.
         In the PCRE documentation the word "newline" is used to mean "the char-
-        acter  or pair of characters that indicate a line break". The choice of
+        acter or pair of characters that indicate a line break". The choice  of
-        newline convention affects the handling of  the  dot,  circumflex,  and
+        newline  convention  affects  the  handling of the dot, circumflex, and
         dollar metacharacters, the handling of #-comments in /x mode, and, when
-        CRLF is a recognized line ending sequence, the match position  advance-
+        CRLF  is a recognized line ending sequence, the match position advance-
         ment for a non-anchored pattern. There is more detail about this in the
         section on pcre_exec() options below.
-        The choice of newline convention does not affect the interpretation  of
+        The  choice of newline convention does not affect the interpretation of
-        the  \n  or  \r  escape  sequences, nor does it affect what \R matches,
+        the \n or \r escape sequences, nor does  it  affect  what  \R  matches,
         which is controlled in a similar way, but by separate options.
  MULTITHREADING
-        The PCRE functions can be used in  multi-threading  applications,  with
+        The  PCRE  functions  can be used in multi-threading applications, with
         the  proviso  that  the  memory  management  functions  pointed  to  by
         pcre_malloc, pcre_free, pcre_stack_malloc, and pcre_stack_free, and the
         callout function pointed to by pcre_callout, are shared by all threads.
-        The  compiled form of a regular expression is not altered during match-
+        The compiled form of a regular expression is not altered during  match-
         ing, so the same compiled pattern can safely be used by several threads
         at once.
+        If the just-in-time optimization feature is being used, it needs  sepa-
+        rate  memory stack areas for each thread. See the pcrejit documentation
+        for more details.
  SAVING PRECOMPILED PATTERNS FOR LATER USE
         The compiled form of a regular expression can be saved and re-used at a
-        later time, possibly by a different program, and even on a  host  other
+        later  time,  possibly by a different program, and even on a host other
-        than  the  one  on  which  it  was  compiled.  Details are given in the
+        than the one on which  it  was  compiled.  Details  are  given  in  the
-        pcreprecompile documentation. However, compiling a  regular  expression
+        pcreprecompile  documentation.  However, compiling a regular expression
-        with  one version of PCRE for use with a different version is not guar-
+        with one version of PCRE for use with a different version is not  guar-
         anteed to work and may cause crashes.
-Line 1072 
 CHECKING BUILD-TIME OPTIONS
+Line 964 
 CHECKING BUILD-TIME OPTIONS
         int pcre_config(int what, void *where);
-        The function pcre_config() makes it possible for a PCRE client to  dis-
+        The  function pcre_config() makes it possible for a PCRE client to dis-
         cover which optional features have been compiled into the PCRE library.
-        The pcrebuild documentation has more details about these optional  fea-
+        The  pcrebuild documentation has more details about these optional fea-
         tures.
-        The  first  argument  for pcre_config() is an integer, specifying which
+        The first argument for pcre_config() is an  integer,  specifying  which
         information is required; the second argument is a pointer to a variable
-        into  which  the  information  is  placed. The following information is
+        into which the information is  placed.  The  following  information  is
         available:
           PCRE_CONFIG_UTF8
-        The output is an integer that is set to one if UTF-8 support is  avail-
+        The  output is an integer that is set to one if UTF-8 support is avail-
         able; otherwise it is set to zero.
           PCRE_CONFIG_UNICODE_PROPERTIES
-        The  output  is  an  integer  that is set to one if support for Unicode
+        The output is an integer that is set to  one  if  support  for  Unicode
         character properties is available; otherwise it is set to zero.
+          PCRE_CONFIG_JIT
+        The output is an integer that is set to one if support for just-in-time
+        compiling is available; otherwise it is set to zero.
           PCRE_CONFIG_NEWLINE
         The output is an integer whose value specifies  the  default  character
-Line 1453 
 COMPILING A PATTERN
+Line 1350 
 COMPILING A PATTERN
         strings  of  UTF-8 characters instead of single-byte character strings.
         However, it is available only when PCRE is built to include UTF-8  sup-
         port.  If not, the use of this option provokes an error. Details of how
-        this option changes the behaviour of PCRE are given in the  section  on
+        this option changes the behaviour of PCRE are given in the  pcreunicode
-        UTF-8 support in the main pcre page.
+        page.
           PCRE_NO_UTF8_CHECK
-Line 1514 
 COMPILATION ERROR CODES
+Line 1411 
 COMPILATION ERROR CODES
  character value in \x{...} sequence is too large
  invalid condition (?(0)
  \C not allowed in lookbehind assertion
- PCRE does not support \L, \l, \N, \U, or \u
+ PCRE does not support \L, \l, \N{name}, \U, or \u
  number after (?C is > 255
  closing ) for (?C expected
  recursive call could loop indefinitely
-Line 1548 
 COMPILATION ERROR CODES
+Line 1445 
 COMPILATION ERROR CODES
                 not allowed
  (*MARK) must have an argument
  this version of PCRE is not compiled with PCRE_UCP support
+ \c must be followed by an ASCII character
+ \k is not followed by a braced, angle-bracketed, or quoted name
         The  numbers  32  and 10000 in errors 48 and 49 are defaults; different
         values may be used if the limits were changed when PCRE was built.
-Line 1576 
 STUDYING A PATTERN
+Line 1475 
 STUDYING A PATTERN
         wants   to   pass   any   of   the   other  fields  to  pcre_exec()  or
         pcre_dfa_exec(), it must set up its own pcre_extra block.
-        The second argument of pcre_study() contains option bits.  At  present,
+        The second argument of pcre_study() contains option bits. There is only
-        no options are defined, and this argument should always be zero.
+        one  option:  PCRE_STUDY_JIT_COMPILE.  If this is set, and the just-in-
+        time compiler is  available,  the  pattern  is  further  compiled  into
+        machine  code  that  executes much faster than the pcre_exec() matching
+        function. If the just-in-time compiler is not available, this option is
+        ignored. All other bits in the options argument must be zero.
+        JIT  compilation  is  a heavyweight optimization. It can take some time
+        for patterns to be analyzed, and for one-off matches  and  simple  pat-
+        terns  the benefit of faster execution might be offset by a much slower
+        study time.  Not all patterns can be optimized by the JIT compiler. For
+        those  that cannot be handled, matching automatically falls back to the
+        pcre_exec() interpreter. For more details, see the  pcrejit  documenta-
+        tion.
         The  third argument for pcre_study() is a pointer for an error message.
         If studying succeeds (even if no data is  returned),  the  variable  it
-Line 1586 
 STUDYING A PATTERN
+Line 1497 
 STUDYING A PATTERN
         must  not  try  to  free it. You should test the error pointer for NULL
         after calling pcre_study(), to be sure that it has run successfully.
-        This is a typical call to pcre_study():
+        When you are finished with a pattern, you can free the memory used  for
+        the study data by calling pcre_free_study(). This function was added to
+        the API for release 8.20. For earlier versions,  the  memory  could  be
+        freed  with  pcre_free(), just like the pattern itself. This will still
+        work in cases where PCRE_STUDY_JIT_COMPILE  is  not  used,  but  it  is
+        advisable to change to the new function when convenient.
+        This  is  a typical way in which pcre_study() is used (except that in a
+        real application there should be tests for errors):
-          pcre_extra *pe;
+          int rc;
-          pe = pcre_study(
+          pcre *re;
+          pcre_extra *sd;
+          re = pcre_compile("pattern", 0, &error, &erroroffset, NULL);
+          sd = pcre_study(
             re,             /* result of pcre_compile() */
-,              /* no options exist */
+,              /* no options */
             &error);        /* set to NULL or points to a message */
+          rc = pcre_exec(   /* see below for details of pcre_exec() options */
+            re, sd, "subject", 7, 0, 0, ovector, 30);
+          ...
+          pcre_free_study(sd);
+          pcre_free(re);
         Studying a pattern does two things: first, a lower bound for the length
         of subject string that is needed to match the pattern is computed. This
-Line 1607 
 STUDYING A PATTERN
+Line 1534 
 STUDYING A PATTERN
         bytes is created. This speeds up finding a position in the  subject  at
         which to start matching.
-        The  two  optimizations  just  described can be disabled by setting the
+        These  two optimizations apply to both pcre_exec() and pcre_dfa_exec().
-        PCRE_NO_START_OPTIMIZE   option    when    calling    pcre_exec()    or
+        However, they are not used by pcre_exec()  if  pcre_study()  is  called
-        pcre_dfa_exec().  You  might  want  to do this if your pattern contains
+        with  the  PCRE_STUDY_JIT_COMPILE option, and just-in-time compiling is
-        callouts or (*MARK), and you want to make use of  these  facilities  in
+        successful.  The  optimizations  can  be  disabled   by   setting   the
-        cases  where  matching fails. See the discussion of PCRE_NO_START_OPTI-
+        PCRE_NO_START_OPTIMIZE    option    when    calling    pcre_exec()   or
-        MIZE below.
+        pcre_dfa_exec(). You might want to do this  if  your  pattern  contains
+        callouts  or (*MARK) (which cannot be handled by the JIT compiler), and
+        you want to make use of these facilities in cases where matching fails.
+        See the discussion of PCRE_NO_START_OPTIMIZE below.
  LOCALE SUPPORT
-        PCRE handles caseless matching, and determines whether  characters  are
+        PCRE  handles  caseless matching, and determines whether characters are
-        letters,  digits, or whatever, by reference to a set of tables, indexed
+        letters, digits, or whatever, by reference to a set of tables,  indexed
-        by character value. When running in UTF-8 mode, this  applies  only  to
+        by  character  value.  When running in UTF-8 mode, this applies only to
-        characters  with  codes  less than 128. By default, higher-valued codes
+        characters with codes less than 128. By  default,  higher-valued  codes
         never match escapes such as \w or \d, but they can be tested with \p if
-        PCRE  is  built with Unicode character property support. Alternatively,
+        PCRE is built with Unicode character property  support.  Alternatively,
-        the PCRE_UCP option can be set at compile  time;  this  causes  \w  and
+        the  PCRE_UCP  option  can  be  set at compile time; this causes \w and
         friends to use Unicode property support instead of built-in tables. The
         use of locales with Unicode is discouraged. If you are handling charac-
-        ters  with codes greater than 128, you should either use UTF-8 and Uni-
+        ters with codes greater than 128, you should either use UTF-8 and  Uni-
         code, or use locales, but not try to mix the two.
-        PCRE contains an internal set of tables that are used  when  the  final
+        PCRE  contains  an  internal set of tables that are used when the final
-        argument  of  pcre_compile()  is  NULL.  These  are sufficient for many
+        argument of pcre_compile() is  NULL.  These  are  sufficient  for  many
         applications.  Normally, the internal tables recognize only ASCII char-
         acters. However, when PCRE is built, it is possible to cause the inter-
         nal tables to be rebuilt in the default "C" locale of the local system,
         which may cause them to be different.
-        The  internal tables can always be overridden by tables supplied by the
+        The internal tables can always be overridden by tables supplied by  the
         application that calls PCRE. These may be created in a different locale
-        from  the  default.  As more and more applications change to using Uni-
+        from the default. As more and more applications change  to  using  Uni-
         code, the need for this locale support is expected to die away.
-        External tables are built by calling  the  pcre_maketables()  function,
+        External  tables  are  built by calling the pcre_maketables() function,
-        which  has no arguments, in the relevant locale. The result can then be
+        which has no arguments, in the relevant locale. The result can then  be
-        passed to pcre_compile() or pcre_exec()  as  often  as  necessary.  For
+        passed  to  pcre_compile()  or  pcre_exec()  as often as necessary. For
-        example,  to  build  and use tables that are appropriate for the French
+        example, to build and use tables that are appropriate  for  the  French
-        locale (where accented characters with  values  greater  than  128  are
+        locale  (where  accented  characters  with  values greater than 128 are
         treated as letters), the following code could be used:
           setlocale(LC_CTYPE, "fr_FR");
           tables = pcre_maketables();
           re = pcre_compile(..., tables);
-        The  locale  name "fr_FR" is used on Linux and other Unix-like systems;
+        The locale name "fr_FR" is used on Linux and other  Unix-like  systems;
         if you are using Windows, the name for the French locale is "french".
-        When pcre_maketables() runs, the tables are built  in  memory  that  is
+        When  pcre_maketables()  runs,  the  tables are built in memory that is
-        obtained  via  pcre_malloc. It is the caller's responsibility to ensure
+        obtained via pcre_malloc. It is the caller's responsibility  to  ensure
-        that the memory containing the tables remains available for as long  as
+        that  the memory containing the tables remains available for as long as
         it is needed.
         The pointer that is passed to pcre_compile() is saved with the compiled
-        pattern, and the same tables are used via this pointer by  pcre_study()
+        pattern,  and the same tables are used via this pointer by pcre_study()
         and normally also by pcre_exec(). Thus, by default, for any single pat-
         tern, compilation, studying and matching all happen in the same locale,
         but different patterns can be compiled in different locales.
-        It  is  possible to pass a table pointer or NULL (indicating the use of
+        It is possible to pass a table pointer or NULL (indicating the  use  of
-        the internal tables) to pcre_exec(). Although  not  intended  for  this
+        the  internal  tables)  to  pcre_exec(). Although not intended for this
-        purpose,  this facility could be used to match a pattern in a different
+        purpose, this facility could be used to match a pattern in a  different
         locale from the one in which it was compiled. Passing table pointers at
         run time is discussed below in the section on matching a pattern.
-Line 1678 
 INFORMATION ABOUT A PATTERN
+Line 1608 
 INFORMATION ABOUT A PATTERN
         int pcre_fullinfo(const pcre *code, const pcre_extra *extra,
              int what, void *where);
-        The  pcre_fullinfo() function returns information about a compiled pat-
+        The pcre_fullinfo() function returns information about a compiled  pat-
         tern. It replaces the obsolete pcre_info() function, which is neverthe-
         less retained for backwards compability (and is documented below).
-        The  first  argument  for  pcre_fullinfo() is a pointer to the compiled
+        The first argument for pcre_fullinfo() is a  pointer  to  the  compiled
-        pattern. The second argument is the result of pcre_study(), or NULL  if
+        pattern.  The second argument is the result of pcre_study(), or NULL if
-        the  pattern  was not studied. The third argument specifies which piece
+        the pattern was not studied. The third argument specifies  which  piece
-        of information is required, and the fourth argument is a pointer  to  a
+        of  information  is required, and the fourth argument is a pointer to a
-        variable  to  receive  the  data. The yield of the function is zero for
+        variable to receive the data. The yield of the  function  is  zero  for
         success, or one of the following negative numbers:
           PCRE_ERROR_NULL       the argument code was NULL
-Line 1694 
 INFORMATION ABOUT A PATTERN
+Line 1624 
 INFORMATION ABOUT A PATTERN
           PCRE_ERROR_BADMAGIC   the "magic number" was not found
           PCRE_ERROR_BADOPTION  the value of what was invalid
-        The "magic number" is placed at the start of each compiled  pattern  as
+        The  "magic  number" is placed at the start of each compiled pattern as
-        an  simple check against passing an arbitrary memory pointer. Here is a
+        an simple check against passing an arbitrary memory pointer. Here is  a
-        typical call of pcre_fullinfo(), to obtain the length of  the  compiled
+        typical  call  of pcre_fullinfo(), to obtain the length of the compiled
         pattern:
           int rc;
           size_t length;
           rc = pcre_fullinfo(
             re,               /* result of pcre_compile() */
-            pe,               /* result of pcre_study(), or NULL */
+            sd,               /* result of pcre_study(), or NULL */
             PCRE_INFO_SIZE,   /* what is required */
             &length);         /* where to put the data */
-        The  possible  values for the third argument are defined in pcre.h, and
+        The possible values for the third argument are defined in  pcre.h,  and
         are as follows:
           PCRE_INFO_BACKREFMAX
-        Return the number of the highest back reference  in  the  pattern.  The
+        Return  the  number  of  the highest back reference in the pattern. The
-        fourth  argument  should  point to an int variable. Zero is returned if
+        fourth argument should point to an int variable. Zero  is  returned  if
         there are no back references.
           PCRE_INFO_CAPTURECOUNT
-        Return the number of capturing subpatterns in the pattern.  The  fourth
+        Return  the  number of capturing subpatterns in the pattern. The fourth
         argument should point to an int variable.
           PCRE_INFO_DEFAULT_TABLES
-        Return  a pointer to the internal default character tables within PCRE.
+        Return a pointer to the internal default character tables within  PCRE.
-        The fourth argument should point to an unsigned char *  variable.  This
+        The  fourth  argument should point to an unsigned char * variable. This
         information call is provided for internal use by the pcre_study() func-
-        tion. External callers can cause PCRE to use  its  internal  tables  by
+        tion.  External  callers  can  cause PCRE to use its internal tables by
         passing a NULL table pointer.
           PCRE_INFO_FIRSTBYTE
-        Return  information  about  the first byte of any matched string, for a
+        Return information about the first byte of any matched  string,  for  a
-        non-anchored pattern. The fourth argument should point to an int  vari-
+        non-anchored  pattern. The fourth argument should point to an int vari-
-        able.  (This option used to be called PCRE_INFO_FIRSTCHAR; the old name
+        able. (This option used to be called PCRE_INFO_FIRSTCHAR; the old  name
         is still recognized for backwards compatibility.)
-        If there is a fixed first byte, for example, from  a  pattern  such  as
+        If  there  is  a  fixed first byte, for example, from a pattern such as
         (cat|cow|coyote), its value is returned. Otherwise, if either
-        (a)  the pattern was compiled with the PCRE_MULTILINE option, and every
+        (a) the pattern was compiled with the PCRE_MULTILINE option, and  every
         branch starts with "^", or
         (b) every branch of the pattern starts with ".*" and PCRE_DOTALL is not
         set (if it were set, the pattern would be anchored),
-        -1  is  returned, indicating that the pattern matches only at the start
+        -1 is returned, indicating that the pattern matches only at  the  start
-        of a subject string or after any newline within the  string.  Otherwise
+        of  a  subject string or after any newline within the string. Otherwise
         -2 is returned. For anchored patterns, -2 is returned.
           PCRE_INFO_FIRSTTABLE
-        If  the pattern was studied, and this resulted in the construction of a
+        If the pattern was studied, and this resulted in the construction of  a
 -bit table indicating a fixed set of bytes for the first byte in any
-        matching  string, a pointer to the table is returned. Otherwise NULL is
+        matching string, a pointer to the table is returned. Otherwise NULL  is
-        returned. The fourth argument should point to an unsigned char *  vari-
+        returned.  The fourth argument should point to an unsigned char * vari-
         able.
           PCRE_INFO_HASCRORLF
-        Return  1  if  the  pattern  contains any explicit matches for CR or LF
+        Return 1 if the pattern contains any explicit  matches  for  CR  or  LF
-        characters, otherwise 0. The fourth argument should  point  to  an  int
+        characters,  otherwise  0.  The  fourth argument should point to an int
-        variable.  An explicit match is either a literal CR or LF character, or
+        variable. An explicit match is either a literal CR or LF character,  or
         \r or \n.
           PCRE_INFO_JCHANGED
-        Return 1 if the (?J) or (?-J) option setting is used  in  the  pattern,
+        Return  1  if  the (?J) or (?-J) option setting is used in the pattern,
-        otherwise  0. The fourth argument should point to an int variable. (?J)
+        otherwise 0. The fourth argument should point to an int variable.  (?J)
         and (?-J) set and unset the local PCRE_DUPNAMES option, respectively.
+          PCRE_INFO_JIT
+        Return  1  if  the  pattern was studied with the PCRE_STUDY_JIT_COMPILE
+        option, and just-in-time compiling was successful. The fourth  argument
+        should  point  to  an  int variable. A return value of 0 means that JIT
+        support is not available in this version of PCRE, or that  the  pattern
+        was not studied with the PCRE_STUDY_JIT_COMPILE option, or that the JIT
+        compiler could not handle this particular pattern. See the pcrejit doc-
+        umentation for details of what can and cannot be handled.
           PCRE_INFO_LASTLITERAL
-        Return the value of the rightmost literal byte that must exist  in  any
+        Return  the  value of the rightmost literal byte that must exist in any
-        matched  string,  other  than  at  its  start,  if such a byte has been
+        matched string, other than at its  start,  if  such  a  byte  has  been
         recorded. The fourth argument should point to an int variable. If there
-        is  no such byte, -1 is returned. For anchored patterns, a last literal
+        is no such byte, -1 is returned. For anchored patterns, a last  literal
-        byte is recorded only if it follows something of variable  length.  For
+        byte  is  recorded only if it follows something of variable length. For
         example, for the pattern /^a\d+z\d+/ the returned value is "z", but for
         /^a\dz\d/ the returned value is -1.
           PCRE_INFO_MINLENGTH
-        If the pattern was studied and a minimum length  for  matching  subject
+        If  the  pattern  was studied and a minimum length for matching subject
-        strings  was  computed,  its  value is returned. Otherwise the returned
+        strings was computed, its value is  returned.  Otherwise  the  returned
-        value is -1. The value is a number of characters, not bytes  (this  may
+        value  is  -1. The value is a number of characters, not bytes (this may
-        be  relevant in UTF-8 mode). The fourth argument should point to an int
+        be relevant in UTF-8 mode). The fourth argument should point to an  int
-        variable. A non-negative value is a lower bound to the  length  of  any
+        variable.  A  non-negative  value is a lower bound to the length of any
-        matching  string.  There  may not be any strings of that length that do
+        matching string. There may not be any strings of that  length  that  do
         actually match, but every string that does match is at least that long.
           PCRE_INFO_NAMECOUNT
           PCRE_INFO_NAMEENTRYSIZE
           PCRE_INFO_NAMETABLE
-        PCRE supports the use of named as well as numbered capturing  parenthe-
+        PCRE  supports the use of named as well as numbered capturing parenthe-
-        ses.  The names are just an additional way of identifying the parenthe-
+        ses. The names are just an additional way of identifying the  parenthe-
         ses, which still acquire numbers. Several convenience functions such as
-        pcre_get_named_substring()  are  provided  for extracting captured sub-
+        pcre_get_named_substring() are provided for  extracting  captured  sub-
-        strings by name. It is also possible to extract the data  directly,  by
+        strings  by  name. It is also possible to extract the data directly, by
-        first  converting  the  name to a number in order to access the correct
+        first converting the name to a number in order to  access  the  correct
         pointers in the output vector (described with pcre_exec() below). To do
-        the  conversion,  you  need  to  use  the  name-to-number map, which is
+        the conversion, you need  to  use  the  name-to-number  map,  which  is
         described by these three values.
         The map consists of a number of fixed-size entries. PCRE_INFO_NAMECOUNT
         gives the number of entries, and PCRE_INFO_NAMEENTRYSIZE gives the size
-        of each entry; both of these  return  an  int  value.  The  entry  size
+        of  each  entry;  both  of  these  return  an int value. The entry size
-        depends  on the length of the longest name. PCRE_INFO_NAMETABLE returns
+        depends on the length of the longest name. PCRE_INFO_NAMETABLE  returns
-        a pointer to the first entry of the table  (a  pointer  to  char).  The
+        a  pointer  to  the  first  entry of the table (a pointer to char). The
         first two bytes of each entry are the number of the capturing parenthe-
-        sis, most significant byte first. The rest of the entry is  the  corre-
+        sis,  most  significant byte first. The rest of the entry is the corre-
         sponding name, zero terminated.
-        The  names are in alphabetical order. Duplicate names may appear if (?|
+        The names are in alphabetical order. Duplicate names may appear if  (?|
         is used to create multiple groups with the same number, as described in
-        the  section  on  duplicate subpattern numbers in the pcrepattern page.
+        the section on duplicate subpattern numbers in  the  pcrepattern  page.
-        Duplicate names for subpatterns with different  numbers  are  permitted
+        Duplicate  names  for  subpatterns with different numbers are permitted
-        only  if  PCRE_DUPNAMES  is  set. In all cases of duplicate names, they
+        only if PCRE_DUPNAMES is set. In all cases  of  duplicate  names,  they
-        appear in the table in the order in which they were found in  the  pat-
+        appear  in  the table in the order in which they were found in the pat-
-        tern.  In  the  absence  of (?| this is the order of increasing number;
+        tern. In the absence of (?| this is the  order  of  increasing  number;
         when (?| is used this is not necessarily the case because later subpat-
         terns may have lower numbers.
-        As  a  simple  example of the name/number table, consider the following
+        As a simple example of the name/number table,  consider  the  following
-        pattern (assume PCRE_EXTENDED is set, so white space -  including  new-
+        pattern  (assume  PCRE_EXTENDED is set, so white space - including new-
         lines - is ignored):
           (?<date> (?<year>(\d\d)?\d\d) -
           (?<month>\d\d) - (?<day>\d\d) )
-        There  are  four  named subpatterns, so the table has four entries, and
+        There are four named subpatterns, so the table has  four  entries,  and
-        each entry in the table is eight bytes long. The table is  as  follows,
+        each  entry  in the table is eight bytes long. The table is as follows,
         with non-printing bytes shows in hexadecimal, and undefined bytes shown
         as ??:
-Line 1840 
 INFORMATION ABOUT A PATTERN
+Line 1780 
 INFORMATION ABOUT A PATTERN
 04 m  o  n  t  h  00
 02 y  e  a  r  00 ??
-        When writing code to extract data  from  named  subpatterns  using  the
+        When  writing  code  to  extract  data from named subpatterns using the
-        name-to-number  map,  remember that the length of the entries is likely
+        name-to-number map, remember that the length of the entries  is  likely
         to be different for each compiled pattern.
           PCRE_INFO_OKPARTIAL
-        Return 1  if  the  pattern  can  be  used  for  partial  matching  with
+        Return  1  if  the  pattern  can  be  used  for  partial  matching with
-        pcre_exec(),  otherwise  0.  The fourth argument should point to an int
+        pcre_exec(), otherwise 0. The fourth argument should point  to  an  int
-        variable. From  release  8.00,  this  always  returns  1,  because  the
+        variable.  From  release  8.00,  this  always  returns  1,  because the
-        restrictions  that  previously  applied  to  partial matching have been
+        restrictions that previously applied  to  partial  matching  have  been
-        lifted. The pcrepartial documentation gives details of  partial  match-
+        lifted.  The  pcrepartial documentation gives details of partial match-
         ing.
           PCRE_INFO_OPTIONS
-        Return  a  copy of the options with which the pattern was compiled. The
+        Return a copy of the options with which the pattern was  compiled.  The
-        fourth argument should point to an unsigned long  int  variable.  These
+        fourth  argument  should  point to an unsigned long int variable. These
         option bits are those specified in the call to pcre_compile(), modified
         by any top-level option settings at the start of the pattern itself. In
-        other  words,  they are the options that will be in force when matching
+        other words, they are the options that will be in force  when  matching
-        starts. For example, if the pattern /(?im)abc(?-i)d/ is  compiled  with
+        starts.  For  example, if the pattern /(?im)abc(?-i)d/ is compiled with
-        the  PCRE_EXTENDED option, the result is PCRE_CASELESS, PCRE_MULTILINE,
+        the PCRE_EXTENDED option, the result is PCRE_CASELESS,  PCRE_MULTILINE,
         and PCRE_EXTENDED.
-        A pattern is automatically anchored by PCRE if  all  of  its  top-level
+        A  pattern  is  automatically  anchored by PCRE if all of its top-level
         alternatives begin with one of the following:
           ^     unless PCRE_MULTILINE is set
-Line 1878 
 INFORMATION ABOUT A PATTERN
+Line 1818 
 INFORMATION ABOUT A PATTERN
           PCRE_INFO_SIZE
-        Return the size of the compiled pattern, that is, the  value  that  was
+        Return  the  size  of the compiled pattern, that is, the value that was
         passed as the argument to pcre_malloc() when PCRE was getting memory in
         which to place the compiled data. The fourth argument should point to a
         size_t variable.
-Line 1886 
 INFORMATION ABOUT A PATTERN
+Line 1826 
 INFORMATION ABOUT A PATTERN
           PCRE_INFO_STUDYSIZE
         Return the size of the data block pointed to by the study_data field in
-        a pcre_extra block. That is,  it  is  the  value  that  was  passed  to
+        a  pcre_extra  block. If pcre_extra is NULL, or there is no study data,
-        pcre_malloc() when PCRE was getting memory into which to place the data
+        zero is returned. The fourth argument should point to  a  size_t  vari-
-        created by pcre_study(). If pcre_extra is NULL, or there  is  no  study
+        able.   The  study_data field is set by pcre_study() to record informa-
-        data,  zero  is  returned. The fourth argument should point to a size_t
+        tion that will speed up matching (see the section entitled "Studying  a
-        variable.
+        pattern" above). The format of the study_data block is private, but its
+        length is made available via this option so that it can  be  saved  and
+        restored (see the pcreprecompile documentation for details).
  OBSOLETE INFO FUNCTION
         int pcre_info(const pcre *code, int *optptr, int *firstcharptr);
-        The pcre_info() function is now obsolete because its interface  is  too
+        The  pcre_info()  function is now obsolete because its interface is too
-        restrictive  to return all the available data about a compiled pattern.
+        restrictive to return all the available data about a compiled  pattern.
-        New  programs  should  use  pcre_fullinfo()  instead.  The   yield   of
+        New   programs   should  use  pcre_fullinfo()  instead.  The  yield  of
-        pcre_info()  is the number of capturing subpatterns, or one of the fol-
+        pcre_info() is the number of capturing subpatterns, or one of the  fol-
         lowing negative numbers:
           PCRE_ERROR_NULL       the argument code was NULL
           PCRE_ERROR_BADMAGIC   the "magic number" was not found
-        If the optptr argument is not NULL, a copy of the  options  with  which
+        If  the  optptr  argument is not NULL, a copy of the options with which
-        the  pattern  was  compiled  is placed in the integer it points to (see
+        the pattern was compiled is placed in the integer  it  points  to  (see
         PCRE_INFO_OPTIONS above).
-        If the pattern is not anchored and the  firstcharptr  argument  is  not
+        If  the  pattern  is  not anchored and the firstcharptr argument is not
-        NULL,  it is used to pass back information about the first character of
+        NULL, it is used to pass back information about the first character  of
         any matched string (see PCRE_INFO_FIRSTBYTE above).
-Line 1919 
 REFERENCE COUNTS
+Line 1861 
 REFERENCE COUNTS
         int pcre_refcount(pcre *code, int adjust);
-        The pcre_refcount() function is used to maintain a reference  count  in
+        The  pcre_refcount()  function is used to maintain a reference count in
         the data block that contains a compiled pattern. It is provided for the
-        benefit of applications that  operate  in  an  object-oriented  manner,
+        benefit  of  applications  that  operate  in an object-oriented manner,
         where different parts of the application may be using the same compiled
         pattern, but you want to free the block when they are all done.
         When a pattern is compiled, the reference count field is initialized to
-        zero.   It is changed only by calling this function, whose action is to
+        zero.  It is changed only by calling this function, whose action is  to
-        add the adjust value (which may be positive or  negative)  to  it.  The
+        add  the  adjust  value  (which may be positive or negative) to it. The
         yield of the function is the new value. However, the value of the count
-        is constrained to lie between 0 and 65535, inclusive. If the new  value
+        is  constrained to lie between 0 and 65535, inclusive. If the new value
         is outside these limits, it is forced to the appropriate limit value.
-        Except  when it is zero, the reference count is not correctly preserved
+        Except when it is zero, the reference count is not correctly  preserved
-        if a pattern is compiled on one host and then  transferred  to  a  host
+        if  a  pattern  is  compiled on one host and then transferred to a host
         whose byte-order is different. (This seems a highly unlikely scenario.)
-Line 1943 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1885 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
              const char *subject, int length, int startoffset,
              int options, int *ovector, int ovecsize);
-        The  function pcre_exec() is called to match a subject string against a
+        The function pcre_exec() is called to match a subject string against  a
-        compiled pattern, which is passed in the code argument. If the  pattern
+        compiled  pattern, which is passed in the code argument. If the pattern
-        was  studied,  the  result  of  the study should be passed in the extra
+        was studied, the result of the study should  be  passed  in  the  extra
-        argument. This function is the main matching facility of  the  library,
+        argument.  You  can call pcre_exec() with the same code and extra argu-
-        and it operates in a Perl-like manner. For specialist use there is also
+        ments as many times as you like, in order to  match  different  subject
-        an alternative matching function, which is described below in the  sec-
+        strings with the same pattern.
-        tion about the pcre_dfa_exec() function.
+        This  function  is  the  main  matching facility of the library, and it
+        operates in a Perl-like manner. For specialist use  there  is  also  an
+        alternative  matching function, which is described below in the section
+        about the pcre_dfa_exec() function.
-        In  most applications, the pattern will have been compiled (and option-
+        In most applications, the pattern will have been compiled (and  option-
-        ally studied) in the same process that calls pcre_exec().  However,  it
+        ally  studied)  in the same process that calls pcre_exec(). However, it
         is possible to save compiled patterns and study data, and then use them
-        later in different processes, possibly even on different hosts.  For  a
+        later  in  different processes, possibly even on different hosts. For a
         discussion about this, see the pcreprecompile documentation.
         Here is an example of a simple call to pcre_exec():
-Line 1973 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1919 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
     Extra data for pcre_exec()
-        If  the  extra argument is not NULL, it must point to a pcre_extra data
+        If the extra argument is not NULL, it must point to a  pcre_extra  data
-        block. The pcre_study() function returns such a block (when it  doesn't
+        block.  The pcre_study() function returns such a block (when it doesn't
-        return  NULL), but you can also create one for yourself, and pass addi-
+        return NULL), but you can also create one for yourself, and pass  addi-
-        tional information in it. The pcre_extra block contains  the  following
+        tional  information  in it. The pcre_extra block contains the following
         fields (not necessarily in this order):
           unsigned long int flags;
           void *study_data;
+          void *executable_jit;
           unsigned long int match_limit;
           unsigned long int match_limit_recursion;
           void *callout_data;
           const unsigned char *tables;
           unsigned char **mark;
-        The  flags  field  is a bitmap that specifies which of the other fields
+        The flags field is a bitmap that specifies which of  the  other  fields
         are set. The flag bits are:
           PCRE_EXTRA_STUDY_DATA
+          PCRE_EXTRA_EXECUTABLE_JIT
           PCRE_EXTRA_MATCH_LIMIT
           PCRE_EXTRA_MATCH_LIMIT_RECURSION
           PCRE_EXTRA_CALLOUT_DATA
           PCRE_EXTRA_TABLES
           PCRE_EXTRA_MARK
-        Other flag bits should be set to zero. The study_data field is  set  in
+        Other  flag  bits should be set to zero. The study_data field and some-
-        the  pcre_extra  block  that is returned by pcre_study(), together with
+        times the executable_jit field are set in the pcre_extra block that  is
-        the appropriate flag bit. You should not set this yourself, but you may
+        returned  by pcre_study(), together with the appropriate flag bits. You
-        add  to  the  block by setting the other fields and their corresponding
+        should not set these yourself, but you may add to the block by  setting
-        flag bits.
+        the other fields and their corresponding flag bits.
         The match_limit field provides a means of preventing PCRE from using up
-        a  vast amount of resources when running patterns that are not going to
+        a vast amount of resources when running patterns that are not going  to
-        match, but which have a very large number  of  possibilities  in  their
+        match,  but  which  have  a very large number of possibilities in their
-        search  trees. The classic example is a pattern that uses nested unlim-
+        search trees. The classic example is a pattern that uses nested  unlim-
         ited repeats.
-        Internally, PCRE uses a function called match() which it calls  repeat-
+        Internally,  pcre_exec() uses a function called match(), which it calls
-        edly  (sometimes  recursively). The limit set by match_limit is imposed
+        repeatedly (sometimes recursively). The limit  set  by  match_limit  is
-        on the number of times this function is called during  a  match,  which
+        imposed  on the number of times this function is called during a match,
-        has  the  effect  of  limiting the amount of backtracking that can take
+        which has the effect of limiting the amount of  backtracking  that  can
-        place. For patterns that are not anchored, the count restarts from zero
+        take place. For patterns that are not anchored, the count restarts from
-        for each position in the subject string.
+        zero for each position in the subject string.
+        When pcre_exec() is called with a pattern that was successfully studied
+        with  the  PCRE_STUDY_JIT_COMPILE  option, the way that the matching is
+        executed is entirely different. However, there is still the possibility
+        of  runaway  matching  that  goes  on  for a very long time, and so the
+        match_limit value is also used in this case (but in a different way) to
+        limit how long the matching can continue.
         The  default  value  for  the  limit can be set when PCRE is built; the
         default default is 10 million, which handles all but the  most  extreme
-Line 2029 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1984 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
         the  total number of calls, because not all calls to match() are recur-
         sive.  This limit is of use only if it is set smaller than match_limit.
-        Limiting the recursion depth limits the amount of  stack  that  can  be
+        Limiting the recursion depth limits the amount of  machine  stack  that
-        used, or, when PCRE has been compiled to use memory on the heap instead
+        can  be used, or, when PCRE has been compiled to use memory on the heap
-        of the stack, the amount of heap memory that can be used.
+        instead of the stack, the amount of heap memory that can be used.  This
+        limit  is not relevant, and is ignored, if the pattern was successfully
+        studied with PCRE_STUDY_JIT_COMPILE.
         The default value for match_limit_recursion can be  set  when  PCRE  is
         built;  the  default  default  is  the  same  value  as the default for
-Line 2074 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2031 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
         PCRE_NO_START_OPTIMIZE,  PCRE_NO_UTF8_CHECK,   PCRE_PARTIAL_SOFT,   and
         PCRE_PARTIAL_HARD.
+        If the pattern was successfully studied with the PCRE_STUDY_JIT_COMPILE
+        option,  the   only   supported   options   for   JIT   execution   are
+        PCRE_NO_UTF8_CHECK,   PCRE_NOTBOL,   PCRE_NOTEOL,   PCRE_NOTEMPTY,  and
+        PCRE_NOTEMPTY_ATSTART. Note in particular that partial matching is  not
+        supported.  If an unsupported option is used, JIT execution is disabled
+        and the normal interpretive code in pcre_exec() is run.
           PCRE_ANCHORED
-        The  PCRE_ANCHORED  option  limits pcre_exec() to matching at the first
+        The PCRE_ANCHORED option limits pcre_exec() to matching  at  the  first
-        matching position. If a pattern was  compiled  with  PCRE_ANCHORED,  or
+        matching  position.  If  a  pattern was compiled with PCRE_ANCHORED, or
-        turned  out to be anchored by virtue of its contents, it cannot be made
+        turned out to be anchored by virtue of its contents, it cannot be  made
         unachored at matching time.
           PCRE_BSR_ANYCRLF
           PCRE_BSR_UNICODE
         These options (which are mutually exclusive) control what the \R escape
-        sequence  matches.  The choice is either to match only CR, LF, or CRLF,
+        sequence matches. The choice is either to match only CR, LF,  or  CRLF,
-        or to match any Unicode newline sequence. These  options  override  the
+        or  to  match  any Unicode newline sequence. These options override the
         choice that was made or defaulted when the pattern was compiled.
           PCRE_NEWLINE_CR
-Line 2095 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2059 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           PCRE_NEWLINE_ANYCRLF
           PCRE_NEWLINE_ANY
-        These  options  override  the  newline  definition  that  was chosen or
+        These options override  the  newline  definition  that  was  chosen  or
-        defaulted when the pattern was compiled. For details, see the  descrip-
+        defaulted  when the pattern was compiled. For details, see the descrip-
-        tion  of  pcre_compile()  above.  During  matching,  the newline choice
+        tion of pcre_compile()  above.  During  matching,  the  newline  choice
-        affects the behaviour of the dot, circumflex,  and  dollar  metacharac-
+        affects  the  behaviour  of the dot, circumflex, and dollar metacharac-
-        ters.  It may also alter the way the match position is advanced after a
+        ters. It may also alter the way the match position is advanced after  a
         match failure for an unanchored pattern.
-        When PCRE_NEWLINE_CRLF, PCRE_NEWLINE_ANYCRLF,  or  PCRE_NEWLINE_ANY  is
+        When  PCRE_NEWLINE_CRLF,  PCRE_NEWLINE_ANYCRLF,  or PCRE_NEWLINE_ANY is
-        set,  and a match attempt for an unanchored pattern fails when the cur-
+        set, and a match attempt for an unanchored pattern fails when the  cur-
-        rent position is at a  CRLF  sequence,  and  the  pattern  contains  no
+        rent  position  is  at  a  CRLF  sequence,  and the pattern contains no
-        explicit  matches  for  CR  or  LF  characters,  the  match position is
+        explicit matches for  CR  or  LF  characters,  the  match  position  is
         advanced by two characters instead of one, in other words, to after the
         CRLF.
         The above rule is a compromise that makes the most common cases work as
-        expected. For example, if the  pattern  is  .+A  (and  the  PCRE_DOTALL
+        expected.  For  example,  if  the  pattern  is .+A (and the PCRE_DOTALL
         option is not set), it does not match the string "\r\nA" because, after
-        failing at the start, it skips both the CR and the LF before  retrying.
+        failing  at the start, it skips both the CR and the LF before retrying.
-        However,  the  pattern  [\r\n]A does match that string, because it con-
+        However, the pattern [\r\n]A does match that string,  because  it  con-
         tains an explicit CR or LF reference, and so advances only by one char-
         acter after the first failure.
         An explicit match for CR of LF is either a literal appearance of one of
-        those characters, or one of the \r or  \n  escape  sequences.  Implicit
+        those  characters,  or  one  of the \r or \n escape sequences. Implicit
-        matches  such  as [^X] do not count, nor does \s (which includes CR and
+        matches such as [^X] do not count, nor does \s (which includes  CR  and
         LF in the characters that it matches).
-        Notwithstanding the above, anomalous effects may still occur when  CRLF
+        Notwithstanding  the above, anomalous effects may still occur when CRLF
         is a valid newline sequence and explicit \r or \n escapes appear in the
         pattern.
           PCRE_NOTBOL
         This option specifies that first character of the subject string is not
-        the  beginning  of  a  line, so the circumflex metacharacter should not
+        the beginning of a line, so the  circumflex  metacharacter  should  not
-        match before it. Setting this without PCRE_MULTILINE (at compile  time)
+        match  before it. Setting this without PCRE_MULTILINE (at compile time)
-        causes  circumflex  never to match. This option affects only the behav-
+        causes circumflex never to match. This option affects only  the  behav-
         iour of the circumflex metacharacter. It does not affect \A.
           PCRE_NOTEOL
         This option specifies that the end of the subject string is not the end
-        of  a line, so the dollar metacharacter should not match it nor (except
+        of a line, so the dollar metacharacter should not match it nor  (except
-        in multiline mode) a newline immediately before it. Setting this  with-
+        in  multiline mode) a newline immediately before it. Setting this with-
         out PCRE_MULTILINE (at compile time) causes dollar never to match. This
-        option affects only the behaviour of the dollar metacharacter. It  does
+        option  affects only the behaviour of the dollar metacharacter. It does
         not affect \Z or \z.
           PCRE_NOTEMPTY
         An empty string is not considered to be a valid match if this option is
-        set. If there are alternatives in the pattern, they are tried.  If  all
+        set.  If  there are alternatives in the pattern, they are tried. If all
-        the  alternatives  match  the empty string, the entire match fails. For
+        the alternatives match the empty string, the entire  match  fails.  For
         example, if the pattern
           a?b?
-        is applied to a string not beginning with "a" or  "b",  it  matches  an
+        is  applied  to  a  string not beginning with "a" or "b", it matches an
-        empty  string at the start of the subject. With PCRE_NOTEMPTY set, this
+        empty string at the start of the subject. With PCRE_NOTEMPTY set,  this
         match is not valid, so PCRE searches further into the string for occur-
         rences of "a" or "b".
           PCRE_NOTEMPTY_ATSTART
-        This  is  like PCRE_NOTEMPTY, except that an empty string match that is
+        This is like PCRE_NOTEMPTY, except that an empty string match  that  is
-        not at the start of  the  subject  is  permitted.  If  the  pattern  is
+        not  at  the  start  of  the  subject  is  permitted. If the pattern is
         anchored, such a match can occur only if the pattern contains \K.
-        Perl     has    no    direct    equivalent    of    PCRE_NOTEMPTY    or
+        Perl    has    no    direct    equivalent    of    PCRE_NOTEMPTY     or
-        PCRE_NOTEMPTY_ATSTART, but it does make a special  case  of  a  pattern
+        PCRE_NOTEMPTY_ATSTART,  but  it  does  make a special case of a pattern
-        match  of  the empty string within its split() function, and when using
+        match of the empty string within its split() function, and  when  using
-        the /g modifier. It is  possible  to  emulate  Perl's  behaviour  after
+        the  /g  modifier.  It  is  possible  to emulate Perl's behaviour after
         matching a null string by first trying the match again at the same off-
-        set with PCRE_NOTEMPTY_ATSTART and  PCRE_ANCHORED,  and  then  if  that
+        set  with  PCRE_NOTEMPTY_ATSTART  and  PCRE_ANCHORED,  and then if that
         fails, by advancing the starting offset (see below) and trying an ordi-
-        nary match again. There is some code that demonstrates how to  do  this
+        nary  match  again. There is some code that demonstrates how to do this
-        in  the  pcredemo sample program. In the most general case, you have to
+        in the pcredemo sample program. In the most general case, you  have  to
-        check to see if the newline convention recognizes CRLF  as  a  newline,
+        check  to  see  if the newline convention recognizes CRLF as a newline,
-        and  if so, and the current character is CR followed by LF, advance the
+        and if so, and the current character is CR followed by LF, advance  the
         starting offset by two characters instead of one.
           PCRE_NO_START_OPTIMIZE
-        There are a number of optimizations that pcre_exec() uses at the  start
+        There  are a number of optimizations that pcre_exec() uses at the start
-        of  a  match,  in  order to speed up the process. For example, if it is
+        of a match, in order to speed up the process. For  example,  if  it  is
         known that an unanchored match must start with a specific character, it
-        searches  the  subject  for that character, and fails immediately if it
+        searches the subject for that character, and fails  immediately  if  it
-        cannot find it, without actually running the  main  matching  function.
+        cannot  find  it,  without actually running the main matching function.
         This means that a special item such as (*COMMIT) at the start of a pat-
-        tern is not considered until after a suitable starting  point  for  the
+        tern  is  not  considered until after a suitable starting point for the
-        match  has been found. When callouts or (*MARK) items are in use, these
+        match has been found. When callouts or (*MARK) items are in use,  these
         "start-up" optimizations can cause them to be skipped if the pattern is
-        never  actually  used.  The start-up optimizations are in effect a pre-
+        never actually used. The start-up optimizations are in  effect  a  pre-
         scan of the subject that takes place before the pattern is run.
-        The PCRE_NO_START_OPTIMIZE option disables the start-up  optimizations,
+        The  PCRE_NO_START_OPTIMIZE option disables the start-up optimizations,
-        possibly  causing  performance  to  suffer,  but ensuring that in cases
+        possibly causing performance to suffer,  but  ensuring  that  in  cases
-        where the result is "no match", the callouts do occur, and  that  items
+        where  the  result is "no match", the callouts do occur, and that items
         such as (*COMMIT) and (*MARK) are considered at every possible starting
-        position in the subject string. If  PCRE_NO_START_OPTIMIZE  is  set  at
+        position  in  the  subject  string. If PCRE_NO_START_OPTIMIZE is set at
         compile time, it cannot be unset at matching time.
-        Setting  PCRE_NO_START_OPTIMIZE  can  change  the outcome of a matching
+        Setting PCRE_NO_START_OPTIMIZE can change the  outcome  of  a  matching
         operation.  Consider the pattern
           (*COMMIT)ABC
-        When this is compiled, PCRE records the fact that a  match  must  start
+        When  this  is  compiled, PCRE records the fact that a match must start
-        with  the  character  "A".  Suppose the subject string is "DEFABC". The
+        with the character "A". Suppose the subject  string  is  "DEFABC".  The
-        start-up optimization scans along the subject, finds "A" and  runs  the
+        start-up  optimization  scans along the subject, finds "A" and runs the
-        first  match attempt from there. The (*COMMIT) item means that the pat-
+        first match attempt from there. The (*COMMIT) item means that the  pat-
-        tern must match the current starting position, which in this  case,  it
+        tern  must  match the current starting position, which in this case, it
-        does.  However,  if  the  same match is run with PCRE_NO_START_OPTIMIZE
+        does. However, if the same match  is  run  with  PCRE_NO_START_OPTIMIZE
-        set, the initial scan along the subject string  does  not  happen.  The
+        set,  the  initial  scan  along the subject string does not happen. The
-        first  match  attempt  is  run  starting  from "D" and when this fails,
+        first match attempt is run starting  from  "D"  and  when  this  fails,
-        (*COMMIT) prevents any further matches  being  tried,  so  the  overall
+        (*COMMIT)  prevents  any  further  matches  being tried, so the overall
-        result  is  "no  match". If the pattern is studied, more start-up opti-
+        result is "no match". If the pattern is studied,  more  start-up  opti-
-        mizations may be used. For example, a minimum length  for  the  subject
+        mizations  may  be  used. For example, a minimum length for the subject
         may be recorded. Consider the pattern
           (*MARK:A)(X|Y)
-        The  minimum  length  for  a  match is one character. If the subject is
+        The minimum length for a match is one  character.  If  the  subject  is
-        "ABC", there will be attempts to  match  "ABC",  "BC",  "C",  and  then
+        "ABC",  there  will  be  attempts  to  match "ABC", "BC", "C", and then
-        finally  an empty string.  If the pattern is studied, the final attempt
+        finally an empty string.  If the pattern is studied, the final  attempt
-        does not take place, because PCRE knows that the subject is too  short,
+        does  not take place, because PCRE knows that the subject is too short,
-        and  so  the  (*MARK) is never encountered.  In this case, studying the
+        and so the (*MARK) is never encountered.  In this  case,  studying  the
-        pattern does not affect the overall match result, which  is  still  "no
+        pattern  does  not  affect the overall match result, which is still "no
         match", but it does affect the auxiliary information that is returned.
           PCRE_NO_UTF8_CHECK
         When PCRE_UTF8 is set at compile time, the validity of the subject as a
-        UTF-8 string is automatically checked when pcre_exec() is  subsequently
+        UTF-8  string is automatically checked when pcre_exec() is subsequently
-        called.   The  value  of  startoffset is also checked to ensure that it
+        called.  The value of startoffset is also checked  to  ensure  that  it
-        points to the start of a UTF-8 character. There is a  discussion  about
+        points  to  the start of a UTF-8 character. There is a discussion about
-        the  validity  of  UTF-8 strings in the section on UTF-8 support in the
+        the validity of UTF-8 strings in the section on UTF-8  support  in  the
-        main pcre page. If  an  invalid  UTF-8  sequence  of  bytes  is  found,
+        main  pcre  page.  If  an  invalid  UTF-8  sequence  of bytes is found,
-        pcre_exec()  returns  the  error  PCRE_ERROR_BADUTF8  or,  if PCRE_PAR-
+        pcre_exec() returns  the  error  PCRE_ERROR_BADUTF8  or,  if  PCRE_PAR-
-        TIAL_HARD is set and the problem is a truncated UTF-8 character at  the
+        TIAL_HARD  is set and the problem is a truncated UTF-8 character at the
-        end  of  the  subject, PCRE_ERROR_SHORTUTF8. In both cases, information
+        end of the subject, PCRE_ERROR_SHORTUTF8. In  both  cases,  information
-        about the precise nature of the error may also  be  returned  (see  the
+        about  the  precise  nature  of the error may also be returned (see the
-        descriptions  of these errors in the section entitled Error return val-
+        descriptions of these errors in the section entitled Error return  val-
         ues from pcre_exec() below).  If startoffset contains a value that does
-        not  point to the start of a UTF-8 character (or to the end of the sub-
+        not point to the start of a UTF-8 character (or to the end of the  sub-
         ject), PCRE_ERROR_BADUTF8_OFFSET is returned.
-        If you already know that your subject is valid, and you  want  to  skip
+        If  you  already  know that your subject is valid, and you want to skip
-        these    checks    for   performance   reasons,   you   can   set   the
+        these   checks   for   performance   reasons,   you   can    set    the
-        PCRE_NO_UTF8_CHECK option when calling pcre_exec(). You might  want  to
+        PCRE_NO_UTF8_CHECK  option  when calling pcre_exec(). You might want to
-        do  this  for the second and subsequent calls to pcre_exec() if you are
+        do this for the second and subsequent calls to pcre_exec() if  you  are
-        making repeated calls to find all  the  matches  in  a  single  subject
+        making  repeated  calls  to  find  all  the matches in a single subject
-        string.  However,  you  should  be  sure  that the value of startoffset
+        string. However, you should be  sure  that  the  value  of  startoffset
-        points to the start of a UTF-8 character (or the end of  the  subject).
+        points  to  the start of a UTF-8 character (or the end of the subject).
-        When  PCRE_NO_UTF8_CHECK is set, the effect of passing an invalid UTF-8
+        When PCRE_NO_UTF8_CHECK is set, the effect of passing an invalid  UTF-8
-        string as a subject or an invalid value of  startoffset  is  undefined.
+        string  as  a  subject or an invalid value of startoffset is undefined.
         Your program may crash.
           PCRE_PARTIAL_HARD
           PCRE_PARTIAL_SOFT
-        These  options turn on the partial matching feature. For backwards com-
+        These options turn on the partial matching feature. For backwards  com-
-        patibility, PCRE_PARTIAL is a synonym for PCRE_PARTIAL_SOFT. A  partial
+        patibility,  PCRE_PARTIAL is a synonym for PCRE_PARTIAL_SOFT. A partial
-        match  occurs if the end of the subject string is reached successfully,
+        match occurs if the end of the subject string is reached  successfully,
-        but there are not enough subject characters to complete the  match.  If
+        but  there  are not enough subject characters to complete the match. If
         this happens when PCRE_PARTIAL_SOFT (but not PCRE_PARTIAL_HARD) is set,
-        matching continues by testing any remaining alternatives.  Only  if  no
+        matching  continues  by  testing any remaining alternatives. Only if no
-        complete  match  can be found is PCRE_ERROR_PARTIAL returned instead of
+        complete match can be found is PCRE_ERROR_PARTIAL returned  instead  of
-        PCRE_ERROR_NOMATCH. In other words,  PCRE_PARTIAL_SOFT  says  that  the
+        PCRE_ERROR_NOMATCH.  In  other  words,  PCRE_PARTIAL_SOFT says that the
-        caller  is  prepared to handle a partial match, but only if no complete
+        caller is prepared to handle a partial match, but only if  no  complete
         match can be found.
-        If PCRE_PARTIAL_HARD is set, it overrides  PCRE_PARTIAL_SOFT.  In  this
+        If  PCRE_PARTIAL_HARD  is  set, it overrides PCRE_PARTIAL_SOFT. In this
-        case,  if  a  partial  match  is found, pcre_exec() immediately returns
+        case, if a partial match  is  found,  pcre_exec()  immediately  returns
-        PCRE_ERROR_PARTIAL, without  considering  any  other  alternatives.  In
+        PCRE_ERROR_PARTIAL,  without  considering  any  other  alternatives. In
-        other  words, when PCRE_PARTIAL_HARD is set, a partial match is consid-
+        other words, when PCRE_PARTIAL_HARD is set, a partial match is  consid-
         ered to be more important that an alternative complete match.
-        In both cases, the portion of the string that was  inspected  when  the
+        In  both  cases,  the portion of the string that was inspected when the
         partial match was found is set as the first matching string. There is a
-        more detailed discussion of partial and  multi-segment  matching,  with
+        more  detailed  discussion  of partial and multi-segment matching, with
         examples, in the pcrepartial documentation.
     The string to be matched by pcre_exec()
-        The  subject string is passed to pcre_exec() as a pointer in subject, a
+        The subject string is passed to pcre_exec() as a pointer in subject,  a
         length (in bytes) in length, and a starting byte offset in startoffset.
-        If  this  is  negative  or  greater  than  the  length  of the subject,
+        If this is  negative  or  greater  than  the  length  of  the  subject,
-        pcre_exec() returns PCRE_ERROR_BADOFFSET. When the starting  offset  is
+        pcre_exec()  returns  PCRE_ERROR_BADOFFSET. When the starting offset is
-        zero,  the  search  for a match starts at the beginning of the subject,
+        zero, the search for a match starts at the beginning  of  the  subject,
         and this is by far the most common case. In UTF-8 mode, the byte offset
-        must  point  to  the start of a UTF-8 character (or the end of the sub-
+        must point to the start of a UTF-8 character (or the end  of  the  sub-
-        ject). Unlike the pattern string, the subject may contain  binary  zero
+        ject).  Unlike  the pattern string, the subject may contain binary zero
         bytes.
-        A  non-zero  starting offset is useful when searching for another match
+        A non-zero starting offset is useful when searching for  another  match
-        in the same subject by calling pcre_exec() again after a previous  suc-
+        in  the same subject by calling pcre_exec() again after a previous suc-
-        cess.   Setting  startoffset differs from just passing over a shortened
+        cess.  Setting startoffset differs from just passing over  a  shortened
-        string and setting PCRE_NOTBOL in the case of  a  pattern  that  begins
+        string  and  setting  PCRE_NOTBOL  in the case of a pattern that begins
         with any kind of lookbehind. For example, consider the pattern
           \Biss\B
-        which  finds  occurrences  of "iss" in the middle of words. (\B matches
+        which finds occurrences of "iss" in the middle of  words.  (\B  matches
-        only if the current position in the subject is not  a  word  boundary.)
+        only  if  the  current position in the subject is not a word boundary.)
-        When  applied  to the string "Mississipi" the first call to pcre_exec()
+        When applied to the string "Mississipi" the first call  to  pcre_exec()
-        finds the first occurrence. If pcre_exec() is called  again  with  just
+        finds  the  first  occurrence. If pcre_exec() is called again with just
-        the  remainder  of  the  subject,  namely  "issipi", it does not match,
+        the remainder of the subject,  namely  "issipi",  it  does  not  match,
         because \B is always false at the start of the subject, which is deemed
-        to  be  a  word  boundary. However, if pcre_exec() is passed the entire
+        to be a word boundary. However, if pcre_exec()  is  passed  the  entire
         string again, but with startoffset set to 4, it finds the second occur-
-        rence  of "iss" because it is able to look behind the starting point to
+        rence of "iss" because it is able to look behind the starting point  to
         discover that it is preceded by a letter.
-        Finding all the matches in a subject is tricky  when  the  pattern  can
+        Finding  all  the  matches  in a subject is tricky when the pattern can
         match an empty string. It is possible to emulate Perl's /g behaviour by
-        first  trying  the  match  again  at  the   same   offset,   with   the
+        first   trying   the   match   again  at  the  same  offset,  with  the
-        PCRE_NOTEMPTY_ATSTART  and  PCRE_ANCHORED  options,  and  then  if that
+        PCRE_NOTEMPTY_ATSTART and  PCRE_ANCHORED  options,  and  then  if  that
-        fails, advancing the starting  offset  and  trying  an  ordinary  match
+        fails,  advancing  the  starting  offset  and  trying an ordinary match
         again. There is some code that demonstrates how to do this in the pcre-
         demo sample program. In the most general case, you have to check to see
-        if  the newline convention recognizes CRLF as a newline, and if so, and
+        if the newline convention recognizes CRLF as a newline, and if so,  and
         the current character is CR followed by LF, advance the starting offset
         by two characters instead of one.
-        If  a  non-zero starting offset is passed when the pattern is anchored,
+        If a non-zero starting offset is passed when the pattern  is  anchored,
         one attempt to match at the given offset is made. This can only succeed
-        if  the  pattern  does  not require the match to be at the start of the
+        if the pattern does not require the match to be at  the  start  of  the
         subject.
     How pcre_exec() returns captured substrings
-        In general, a pattern matches a certain portion of the subject, and  in
+        In  general, a pattern matches a certain portion of the subject, and in
-        addition,  further  substrings  from  the  subject may be picked out by
+        addition, further substrings from the subject  may  be  picked  out  by
-        parts of the pattern. Following the usage  in  Jeffrey  Friedl's  book,
+        parts  of  the  pattern.  Following the usage in Jeffrey Friedl's book,
-        this  is  called "capturing" in what follows, and the phrase "capturing
+        this is called "capturing" in what follows, and the  phrase  "capturing
-        subpattern" is used for a fragment of a pattern that picks out  a  sub-
+        subpattern"  is  used for a fragment of a pattern that picks out a sub-
-        string.  PCRE  supports several other kinds of parenthesized subpattern
+        string. PCRE supports several other kinds of  parenthesized  subpattern
         that do not cause substrings to be captured.
         Captured substrings are returned to the caller via a vector of integers
-        whose  address is passed in ovector. The number of elements in the vec-
+        whose address is passed in ovector. The number of elements in the  vec-
-        tor is passed in ovecsize, which must be a non-negative  number.  Note:
+        tor  is  passed in ovecsize, which must be a non-negative number. Note:
         this argument is NOT the size of ovector in bytes.
-        The  first  two-thirds of the vector is used to pass back captured sub-
+        The first two-thirds of the vector is used to pass back  captured  sub-
-        strings, each substring using a pair of integers. The  remaining  third
+        strings,  each  substring using a pair of integers. The remaining third
-        of  the  vector is used as workspace by pcre_exec() while matching cap-
+        of the vector is used as workspace by pcre_exec() while  matching  cap-
-        turing subpatterns, and is not available for passing back  information.
+        turing  subpatterns, and is not available for passing back information.
-        The  number passed in ovecsize should always be a multiple of three. If
+        The number passed in ovecsize should always be a multiple of three.  If
         it is not, it is rounded down.
-        When a match is successful, information about  captured  substrings  is
+        When  a  match  is successful, information about captured substrings is
-        returned  in  pairs  of integers, starting at the beginning of ovector,
+        returned in pairs of integers, starting at the  beginning  of  ovector,
-        and continuing up to two-thirds of its length at the  most.  The  first
+        and  continuing  up  to two-thirds of its length at the most. The first
-        element  of  each pair is set to the byte offset of the first character
+        element of each pair is set to the byte offset of the  first  character
-        in a substring, and the second is set to the byte offset of  the  first
+        in  a  substring, and the second is set to the byte offset of the first
-        character  after  the end of a substring. Note: these values are always
+        character after the end of a substring. Note: these values  are  always
         byte offsets, even in UTF-8 mode. They are not character counts.
-        The first pair of integers, ovector[0]  and  ovector[1],  identify  the
+        The  first  pair  of  integers, ovector[0] and ovector[1], identify the
-        portion  of  the subject string matched by the entire pattern. The next
+        portion of the subject string matched by the entire pattern.  The  next
-        pair is used for the first capturing subpattern, and so on.  The  value
+        pair  is  used for the first capturing subpattern, and so on. The value
         returned by pcre_exec() is one more than the highest numbered pair that
-        has been set.  For example, if two substrings have been  captured,  the
+        has  been  set.  For example, if two substrings have been captured, the
-        returned  value is 3. If there are no capturing subpatterns, the return
+        returned value is 3. If there are no capturing subpatterns, the  return
         value from a successful match is 1, indicating that just the first pair
         of offsets has been set.
         If a capturing subpattern is matched repeatedly, it is the last portion
         of the string that it matched that is returned.
-        If the vector is too small to hold all the captured substring  offsets,
+        If  the vector is too small to hold all the captured substring offsets,
         it is used as far as possible (up to two-thirds of its length), and the
-        function returns a value of zero. If the substring offsets are  not  of
+        function  returns a value of zero. If neither the actual string matched
-        interest,  pcre_exec()  may  be  called with ovector passed as NULL and
+        not any captured substrings are of interest, pcre_exec() may be  called
-        ovecsize as zero. However, if the pattern contains back references  and
+        with  ovector passed as NULL and ovecsize as zero. However, if the pat-
-        the  ovector is not big enough to remember the related substrings, PCRE
+        tern contains back references and the ovector  is  not  big  enough  to
-        has to get additional memory for use during matching. Thus it  is  usu-
+        remember  the related substrings, PCRE has to get additional memory for
-        ally advisable to supply an ovector.
+        use during matching. Thus it is usually advisable to supply an  ovector
+        of reasonable size.
+        There  are  some  cases where zero is returned (indicating vector over-
+        flow) when in fact the vector is exactly the right size for  the  final
+        match. For example, consider the pattern
+          (a)(?:(b)c|bd)
+        If  a  vector of 6 elements (allowing for only 1 captured substring) is
+        given with subject string "abd", pcre_exec() will try to set the second
+        captured string, thereby recording a vector overflow, before failing to
+        match "c" and backing up  to  try  the  second  alternative.  The  zero
+        return,  however,  does  correctly  indicate that the maximum number of
+        slots (namely 2) have been filled. In similar cases where there is tem-
+        porary  overflow,  but  the final number of used slots is actually less
+        than the maximum, a non-zero value is returned.
         The pcre_fullinfo() function can be used to find out how many capturing
-        subpatterns there are in a compiled  pattern.  The  smallest  size  for
+        subpatterns  there  are  in  a  compiled pattern. The smallest size for
-        ovector  that  will allow for n captured substrings, in addition to the
+        ovector that will allow for n captured substrings, in addition  to  the
         offsets of the substring matched by the whole pattern, is (n+1)*3.
-        It is possible for capturing subpattern number n+1 to match  some  part
+        It  is  possible for capturing subpattern number n+1 to match some part
         of the subject when subpattern n has not been used at all. For example,
-        if the string "abc" is matched  against  the  pattern  (a|(z))(bc)  the
+        if  the  string  "abc"  is  matched against the pattern (a|(z))(bc) the
         return from the function is 4, and subpatterns 1 and 3 are matched, but
-is not. When this happens, both values in  the  offset  pairs  corre-
+ is  not.  When  this happens, both values in the offset pairs corre-
         sponding to unused subpatterns are set to -1.
-        Offset  values  that correspond to unused subpatterns at the end of the
+        Offset values that correspond to unused subpatterns at the end  of  the
-        expression are also set to -1. For example,  if  the  string  "abc"  is
+        expression  are  also  set  to  -1. For example, if the string "abc" is
-        matched  against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are not
+        matched against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are  not
-        matched. The return from the function is 2, because  the  highest  used
+        matched.  The  return  from the function is 2, because the highest used
-        capturing  subpattern  number  is 1, and the offsets for for the second
+        capturing subpattern number is 1, and the offsets for  for  the  second
-        and third capturing subpatterns (assuming the vector is  large  enough,
+        and  third  capturing subpatterns (assuming the vector is large enough,
         of course) are set to -1.
-        Note: Elements of ovector that do not correspond to capturing parenthe-
+        Note: Elements in the first two-thirds of ovector that  do  not  corre-
-        ses in the pattern are never changed. That is, if a pattern contains  n
+        spond  to  capturing parentheses in the pattern are never changed. That
-        capturing parentheses, no more than ovector[0] to ovector[2n+1] are set
+        is, if a pattern contains n capturing parentheses, no more  than  ovec-
-        by pcre_exec(). The other elements retain whatever values  they  previ-
+        tor[0]  to ovector[2n+1] are set by pcre_exec(). The other elements (in
-        ously had.
+        the first two-thirds) retain whatever values they previously had.
-        Some  convenience  functions  are  provided for extracting the captured
+        Some convenience functions are provided  for  extracting  the  captured
         substrings as separate strings. These are described below.
     Error return values from pcre_exec()
-        If pcre_exec() fails, it returns a negative number. The  following  are
+        If  pcre_exec()  fails, it returns a negative number. The following are
         defined in the header file:
           PCRE_ERROR_NOMATCH        (-1)
-Line 2416 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2396 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           PCRE_ERROR_NULL           (-2)
-        Either  code  or  subject  was  passed as NULL, or ovector was NULL and
+        Either code or subject was passed as NULL,  or  ovector  was  NULL  and
         ovecsize was not zero.
           PCRE_ERROR_BADOPTION      (-3)
-Line 2425 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2405 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           PCRE_ERROR_BADMAGIC       (-4)
-        PCRE stores a 4-byte "magic number" at the start of the compiled  code,
+        PCRE  stores a 4-byte "magic number" at the start of the compiled code,
         to catch the case when it is passed a junk pointer and to detect when a
         pattern that was compiled in an environment of one endianness is run in
-        an  environment  with the other endianness. This is the error that PCRE
+        an environment with the other endianness. This is the error  that  PCRE
         gives when the magic number is not present.
           PCRE_ERROR_UNKNOWN_OPCODE (-5)
         While running the pattern match, an unknown item was encountered in the
-        compiled  pattern.  This  error  could be caused by a bug in PCRE or by
+        compiled pattern. This error could be caused by a bug  in  PCRE  or  by
         overwriting of the compiled pattern.
           PCRE_ERROR_NOMEMORY       (-6)
-        If a pattern contains back references, but the ovector that  is  passed
+        If  a  pattern contains back references, but the ovector that is passed
         to pcre_exec() is not big enough to remember the referenced substrings,
-        PCRE gets a block of memory at the start of matching to  use  for  this
+        PCRE  gets  a  block of memory at the start of matching to use for this
-        purpose.  If the call via pcre_malloc() fails, this error is given. The
+        purpose. If the call via pcre_malloc() fails, this error is given.  The
         memory is automatically freed at the end of matching.
-        This error is also given if pcre_stack_malloc() fails  in  pcre_exec().
+        This  error  is also given if pcre_stack_malloc() fails in pcre_exec().
-        This  can happen only when PCRE has been compiled with --disable-stack-
+        This can happen only when PCRE has been compiled with  --disable-stack-
         for-recursion.
           PCRE_ERROR_NOSUBSTRING    (-7)
-        This error is used by the pcre_copy_substring(),  pcre_get_substring(),
+        This  error is used by the pcre_copy_substring(), pcre_get_substring(),
         and  pcre_get_substring_list()  functions  (see  below).  It  is  never
         returned by pcre_exec().
           PCRE_ERROR_MATCHLIMIT     (-8)
-        The backtracking limit, as specified by  the  match_limit  field  in  a
+        The  backtracking  limit,  as  specified  by the match_limit field in a
-        pcre_extra  structure  (or  defaulted) was reached. See the description
+        pcre_extra structure (or defaulted) was reached.  See  the  description
         above.
           PCRE_ERROR_CALLOUT        (-9)
         This error is never generated by pcre_exec() itself. It is provided for
-        use  by  callout functions that want to yield a distinctive error code.
+        use by callout functions that want to yield a distinctive  error  code.
         See the pcrecallout documentation for details.
           PCRE_ERROR_BADUTF8        (-10)
-        A string that contains an invalid UTF-8 byte sequence was passed  as  a
+        A  string  that contains an invalid UTF-8 byte sequence was passed as a
-        subject,  and the PCRE_NO_UTF8_CHECK option was not set. If the size of
+        subject, and the PCRE_NO_UTF8_CHECK option was not set. If the size  of
-        the output vector (ovecsize) is at least 2,  the  byte  offset  to  the
+        the  output  vector  (ovecsize)  is  at least 2, the byte offset to the
-        start  of  the  the invalid UTF-8 character is placed in the first ele-
+        start of the the invalid UTF-8 character is placed in  the  first  ele-
-        ment, and a reason code is placed in the  second  element.  The  reason
+        ment,  and  a  reason  code is placed in the second element. The reason
         codes are listed in the following section.  For backward compatibility,
-        if PCRE_PARTIAL_HARD is set and the problem is a truncated UTF-8  char-
+        if  PCRE_PARTIAL_HARD is set and the problem is a truncated UTF-8 char-
-        acter   at   the   end   of   the   subject  (reason  codes  1  to  5),
+        acter  at  the  end  of  the   subject   (reason   codes   1   to   5),
         PCRE_ERROR_SHORTUTF8 is returned instead of PCRE_ERROR_BADUTF8.
           PCRE_ERROR_BADUTF8_OFFSET (-11)
-        The UTF-8 byte sequence that was passed as a subject  was  checked  and
+        The  UTF-8  byte  sequence that was passed as a subject was checked and
-        found  to be valid (the PCRE_NO_UTF8_CHECK option was not set), but the
+        found to be valid (the PCRE_NO_UTF8_CHECK option was not set), but  the
-        value of startoffset did not point to the beginning of a UTF-8  charac-
+        value  of startoffset did not point to the beginning of a UTF-8 charac-
         ter or the end of the subject.
           PCRE_ERROR_PARTIAL        (-12)
-        The  subject  string did not match, but it did match partially. See the
+        The subject string did not match, but it did match partially.  See  the
         pcrepartial documentation for details of partial matching.
           PCRE_ERROR_BADPARTIAL     (-13)
-        This code is no longer in  use.  It  was  formerly  returned  when  the
+        This  code  is  no  longer  in  use.  It was formerly returned when the
-        PCRE_PARTIAL  option  was used with a compiled pattern containing items
+        PCRE_PARTIAL option was used with a compiled pattern  containing  items
-        that were  not  supported  for  partial  matching.  From  release  8.00
+        that  were  not  supported  for  partial  matching.  From  release 8.00
         onwards, there are no restrictions on partial matching.
           PCRE_ERROR_INTERNAL       (-14)
-        An  unexpected  internal error has occurred. This error could be caused
+        An unexpected internal error has occurred. This error could  be  caused
         by a bug in PCRE or by overwriting of the compiled pattern.
           PCRE_ERROR_BADCOUNT       (-15)
-Line 2510 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2490 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           PCRE_ERROR_RECURSIONLIMIT (-21)
         The internal recursion limit, as specified by the match_limit_recursion
-        field  in  a  pcre_extra  structure (or defaulted) was reached. See the
+        field in a pcre_extra structure (or defaulted)  was  reached.  See  the
         description above.
           PCRE_ERROR_BADNEWLINE     (-23)
-Line 2524 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2504 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           PCRE_ERROR_SHORTUTF8      (-25)
-        This  error  is returned instead of PCRE_ERROR_BADUTF8 when the subject
+        This error is returned instead of PCRE_ERROR_BADUTF8 when  the  subject
-        string ends with a truncated UTF-8 character and the  PCRE_PARTIAL_HARD
+        string  ends with a truncated UTF-8 character and the PCRE_PARTIAL_HARD
-        option  is  set.   Information  about  the  failure  is returned as for
+        option is set.  Information  about  the  failure  is  returned  as  for
-        PCRE_ERROR_BADUTF8. It is in fact sufficient to detect this  case,  but
+        PCRE_ERROR_BADUTF8.  It  is in fact sufficient to detect this case, but
-        this  special error code for PCRE_PARTIAL_HARD precedes the implementa-
+        this special error code for PCRE_PARTIAL_HARD precedes the  implementa-
-        tion of returned information; it is retained for backwards  compatibil-
+        tion  of returned information; it is retained for backwards compatibil-
         ity.
           PCRE_ERROR_RECURSELOOP    (-26)
         This error is returned when pcre_exec() detects a recursion loop within
-        the pattern. Specifically, it means that either the whole pattern or  a
+        the  pattern. Specifically, it means that either the whole pattern or a
-        subpattern  has been called recursively for the second time at the same
+        subpattern has been called recursively for the second time at the  same
         position in the subject string. Some simple patterns that might do this
-        are  detected  and faulted at compile time, but more complicated cases,
+        are detected and faulted at compile time, but more  complicated  cases,
         in particular mutual recursions between two different subpatterns, can-
         not be detected until run time.
+          PCRE_ERROR_JIT_STACKLIMIT (-27)
+        This error is returned when a pattern  that  was  successfully  studied
+        using  the PCRE_STUDY_JIT_COMPILE option is being matched, but the mem-
+        ory available for  the  just-in-time  processing  stack  is  not  large
+        enough. See the pcrejit documentation for more details.
         Error numbers -16 to -20 and -22 are not used by pcre_exec().
     Reason codes for invalid UTF-8 strings
-Line 2936 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
+Line 2923 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
         The strings are returned in reverse order of length; that is, the long-
         est  matching  string is given first. If there were too many matches to
         fit into ovector, the yield of the function is zero, and the vector  is
-        filled with the longest matches.
+        filled  with  the  longest matches. Unlike pcre_exec(), pcre_dfa_exec()
+        can use the entire ovector for returning matched strings.
     Error returns from pcre_dfa_exec()
-        The  pcre_dfa_exec()  function returns a negative number when it fails.
+        The pcre_dfa_exec() function returns a negative number when  it  fails.
-        Many of the errors are the same  as  for  pcre_exec(),  and  these  are
+        Many  of  the  errors  are  the  same as for pcre_exec(), and these are
-        described  above.   There are in addition the following errors that are
+        described above.  There are in addition the following errors  that  are
         specific to pcre_dfa_exec():
           PCRE_ERROR_DFA_UITEM      (-16)
-        This return is given if pcre_dfa_exec() encounters an item in the  pat-
+        This  return is given if pcre_dfa_exec() encounters an item in the pat-
-        tern  that  it  does not support, for instance, the use of \C or a back
+        tern that it does not support, for instance, the use of \C  or  a  back
         reference.
           PCRE_ERROR_DFA_UCOND      (-17)
-        This return is given if pcre_dfa_exec()  encounters  a  condition  item
+        This  return  is  given  if pcre_dfa_exec() encounters a condition item
-        that  uses  a back reference for the condition, or a test for recursion
+        that uses a back reference for the condition, or a test  for  recursion
         in a specific group. These are not supported.
           PCRE_ERROR_DFA_UMLIMIT    (-18)
-        This return is given if pcre_dfa_exec() is called with an  extra  block
+        This  return  is given if pcre_dfa_exec() is called with an extra block
-        that contains a setting of the match_limit field. This is not supported
+        that contains a setting of  the  match_limit  or  match_limit_recursion
-        (it is meaningless).
+        fields.  This  is  not  supported (these fields are meaningless for DFA
+        matching).
           PCRE_ERROR_DFA_WSSIZE     (-19)
-Line 2991 
 AUTHOR
+Line 2980 
 AUTHOR
  REVISION
-        Last updated: 28 July 2011
+        Last updated: 23 September 2011
         Copyright (c) 1997-2011 University of Cambridge.
  ------------------------------------------------------------------------------
-Line 3039 
 PCRE CALLOUTS
+Line 3028 
 PCRE CALLOUTS
         pattern is matched. This is useful information when you are  trying  to
         optimize the performance of a particular pattern.
+        The  use  of callouts in a pattern makes it ineligible for optimization
+        by  the  just-in-time  compiler.  Studying  such  a  pattern  with  the
+        PCRE_STUDY_JIT_COMPILE option always fails.
  MISSING CALLOUTS
-Line 3180 
 AUTHOR
+Line 3173 
 AUTHOR
  REVISION
-        Last updated: 31 July 2011
+        Last updated: 26 August 2011
         Copyright (c) 1997-2011 University of Cambridge.
  ------------------------------------------------------------------------------
-Line 3199 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 3192 
 DIFFERENCES BETWEEN PCRE AND PERL
         respect to Perl versions 5.10 and above.
 .  PCRE has only a subset of Perl's UTF-8 and Unicode support. Details
-        of what it does have are given in the section on UTF-8 support  in  the
+        of what it does have are given in the pcreunicode page.
-        main pcre page.
 . PCRE allows repeat quantifiers only on parenthesized assertions, but
-        they do not mean what you might think. For example, (?!a){3}  does  not
+        they  do  not mean what you might think. For example, (?!a){3} does not
         assert that the next three characters are not "a". It just asserts that
         the next character is not "a" three times (in principle: PCRE optimizes
         this to run the assertion just once). Perl allows repeat quantifiers on
         other assertions such as \b, but these do not seem to have any use.
-. Capturing subpatterns that occur inside  negative  lookahead  asser-
+.  Capturing  subpatterns  that occur inside negative lookahead asser-
-        tions  are  counted,  but their entries in the offsets vector are never
+        tions are counted, but their entries in the offsets  vector  are  never
-        set. Perl sets its numerical variables from any such patterns that  are
+        set.  Perl sets its numerical variables from any such patterns that are
         matched before the assertion fails to match something (thereby succeed-
-        ing), but only if the negative lookahead assertion  contains  just  one
+        ing),  but  only  if the negative lookahead assertion contains just one
         branch.
-.  Though  binary zero characters are supported in the subject string,
+. Though binary zero characters are supported in the  subject  string,
         they are not allowed in a pattern string because it is passed as a nor-
         mal C string, terminated by zero. The escape sequence \0 can be used in
         the pattern to represent a binary zero.
-. The following Perl escape sequences are not supported: \l,  \u,  \L,
+.  The  following Perl escape sequences are not supported: \l, \u, \L,
-        \U,  and  \N when followed by a character name or Unicode value. (\N on
+        \U, and \N when followed by a character name or Unicode value.  (\N  on
         its own, matching a non-newline character, is supported.) In fact these
-        are  implemented  by Perl's general string-handling and are not part of
+        are implemented by Perl's general string-handling and are not  part  of
-        its pattern matching engine. If any of these are encountered  by  PCRE,
+        its  pattern  matching engine. If any of these are encountered by PCRE,
         an error is generated.
-.  The Perl escape sequences \p, \P, and \X are supported only if PCRE
+. The Perl escape sequences \p, \P, and \X are supported only if  PCRE
-        is built with Unicode character property support. The  properties  that
+        is  built  with Unicode character property support. The properties that
-        can  be tested with \p and \P are limited to the general category prop-
+        can be tested with \p and \P are limited to the general category  prop-
-        erties such as Lu and Nd, script names such as Greek or  Han,  and  the
+        erties  such  as  Lu and Nd, script names such as Greek or Han, and the
-        derived  properties  Any  and  L&. PCRE does support the Cs (surrogate)
+        derived properties Any and L&. PCRE does  support  the  Cs  (surrogate)
-        property, which Perl does not; the  Perl  documentation  says  "Because
+        property,  which  Perl  does  not; the Perl documentation says "Because
         Perl hides the need for the user to understand the internal representa-
-        tion of Unicode characters, there is no need to implement the  somewhat
+        tion  of Unicode characters, there is no need to implement the somewhat
         messy concept of surrogates."
-.  PCRE implements a simpler version of \X than Perl, which changed to
+. PCRE implements a simpler version of \X than Perl, which changed  to
-        make \X match what Unicode calls an "extended grapheme  cluster".  This
+        make  \X  match what Unicode calls an "extended grapheme cluster". This
-        is  more  complicated  than an extended Unicode sequence, which is what
+        is more complicated than an extended Unicode sequence,  which  is  what
         PCRE matches.
 . PCRE does support the \Q...\E escape for quoting substrings. Charac-
-        ters  in  between  are  treated as literals. This is slightly different
+        ters in between are treated as literals.  This  is  slightly  different
-        from Perl in that $ and @ are  also  handled  as  literals  inside  the
+        from  Perl  in  that  $  and  @ are also handled as literals inside the
-        quotes.  In Perl, they cause variable interpolation (but of course PCRE
+        quotes. In Perl, they cause variable interpolation (but of course  PCRE
         does not have variables). Note the following examples:
             Pattern            PCRE matches      Perl matches
-Line 3256 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 3248 
 DIFFERENCES BETWEEN PCRE AND PERL
             \Qabc\$xyz\E       abc\$xyz          abc\$xyz
             \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
-        The \Q...\E sequence is recognized both inside  and  outside  character
+        The  \Q...\E  sequence  is recognized both inside and outside character
         classes.
 . Fairly obviously, PCRE does not support the (?{code}) and (??{code})
-        constructions. However, there is support for recursive  patterns.  This
+        constructions.  However,  there is support for recursive patterns. This
-        is  not  available  in Perl 5.8, but it is in Perl 5.10. Also, the PCRE
+        is not available in Perl 5.8, but it is in Perl 5.10.  Also,  the  PCRE
-        "callout" feature allows an external function to be called during  pat-
+        "callout"  feature allows an external function to be called during pat-
         tern matching. See the pcrecallout documentation for details.
-.  Subpatterns  that  are  called recursively or as "subroutines" are
+. Subpatterns that are called as subroutines (whether or  not  recur-
-        always treated as atomic groups in  PCRE.  This  is  like  Python,  but
+        sively)  are  always  treated  as  atomic  groups in PCRE. This is like
-        unlike  Perl. There is a discussion of an example that explains this in
+        Python, but unlike Perl.  Captured values that are set outside  a  sub-
-        more detail in the section on recursion differences from  Perl  in  the
+        routine  call  can  be  reference from inside in PCRE, but not in Perl.
-        pcrepattern page.
+        There is a discussion that explains these differences in more detail in
+        the section on recursion differences from Perl in the pcrepattern page.
+.  If  (*THEN)  is present in a group that is called as a subroutine,
+        its action is limited to that group, even if the group does not contain
+        any | characters.
 .  There are some differences that are concerned with the settings of
         captured strings when part of  a  pattern  is  repeated.  For  example,
         matching  "aba"  against  the  pattern  /^(a(b)?)+$/  in Perl leaves $2
         unset, but in PCRE it is set to "b".
 . PCRE's handling of duplicate subpattern numbers and duplicate  sub-
         pattern names is not as general as Perl's. This is a consequence of the
         fact the PCRE works internally just with numbers, using an external ta-
         ble  to  translate  between numbers and names. In particular, a pattern
-Line 3287 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 3284 
 DIFFERENCES BETWEEN PCRE AND PERL
         turing subpattern number 1. To avoid this confusing situation, an error
         is given at compile time.
 .  Perl  recognizes  comments  in some places that PCRE does not, for
         example, between the ( and ? at the start of a subpattern.  If  the  /x
         modifier  is set, Perl allows whitespace between ( and ? but PCRE never
         does, even if the PCRE_EXTENDED option is set.
 . PCRE provides some extensions to the Perl regular expression facil-
         ities.   Perl  5.10  includes new features that are not in earlier ver-
         sions of Perl, some of which (such as named parentheses) have  been  in
         PCRE for some time. This list is with respect to Perl 5.10:
-Line 3328 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 3325 
 DIFFERENCES BETWEEN PCRE AND PERL
         (i) The partial matching facility is PCRE-specific.
         (j) Patterns compiled by PCRE can be saved and re-used at a later time,
-        even on different hosts that have the other endianness.
+        even on different hosts that have the other endianness.  However,  this
+        does not apply to optimized data created by the just-in-time compiler.
-        (k) The alternative matching function (pcre_dfa_exec())  matches  in  a
+        (k)  The  alternative  matching function (pcre_dfa_exec()) matches in a
         different way and is not Perl-compatible.
-        (l)  PCRE  recognizes some special sequences such as (*CR) at the start
+        (l) PCRE recognizes some special sequences such as (*CR) at  the  start
         of a pattern that set overall options that cannot be changed within the
         pattern.
-Line 3347 
 AUTHOR
+Line 3345 
 AUTHOR
  REVISION
-        Last updated: 24 July 2011
+        Last updated: 09 October 2011
         Copyright (c) 1997-2011 University of Cambridge.
  ------------------------------------------------------------------------------
-Line 3387 
 PCRE REGULAR EXPRESSION DETAILS
+Line 3385 
 PCRE REGULAR EXPRESSION DETAILS
         Starting a pattern with this sequence  is  equivalent  to  setting  the
         PCRE_UTF8  option.  This  feature  is  not Perl-compatible. How setting
         UTF-8 mode affects pattern matching  is  mentioned  in  several  places
-        below.  There  is  also  a  summary of UTF-8 features in the section on
+        below.  There  is  also  a summary of UTF-8 features in the pcreunicode
-        UTF-8 support in the main pcre page.
+        page.
         Another special sequence that may appear at the start of a  pattern  or
         in combination with (*UTF8) is:
-Line 4144 
 FULL STOP (PERIOD, DOT) AND \N
+Line 4142 
 FULL STOP (PERIOD, DOT) AND \N
  MATCHING A SINGLE BYTE
         Outside a character class, the escape sequence \C matches any one byte,
-        both  in  and  out  of  UTF-8 mode. Unlike a dot, it always matches any
+        both  in  and  out of UTF-8 mode. Unlike a dot, it always matches line-
-        line-ending characters. The feature is provided in  Perl  in  order  to
+        ending characters. The feature is provided in Perl in  order  to  match
-        match  individual bytes in UTF-8 mode. Because it breaks up UTF-8 char-
+        individual  bytes  in UTF-8 mode, but it is unclear how it can usefully
-        acters into individual bytes, the rest of the string may start  with  a
+        be used. Because \C breaks up characters into individual bytes,  match-
-        malformed  UTF-8  character. For this reason, the \C escape sequence is
+        ing  one  byte  with \C in UTF-8 mode means that the rest of the string
-        best avoided.
+        may start with a malformed UTF-8 character. This has undefined results,
+        because  PCRE  assumes that it is dealing with valid UTF-8 strings (and
+        by default it checks  this  at  the  start  of  processing  unless  the
+        PCRE_NO_UTF8_CHECK option is used).
-        PCRE does not allow \C to appear in  lookbehind  assertions  (described
+        PCRE  does  not  allow \C to appear in lookbehind assertions (described
-        below),  because  in UTF-8 mode this would make it impossible to calcu-
+        below), because in UTF-8 mode this would make it impossible  to  calcu-
         late the length of the lookbehind.
+        In  general, the \C escape sequence is best avoided in UTF-8 mode. How-
+        ever, one way of using it that avoids the problem  of  malformed  UTF-8
+        characters  is to use a lookahead to check the length of the next char-
+        acter, as in this pattern (ignore white space and line breaks):
+          (?| (?=[\x00-\x7f])(\C) |
+              (?=[\x80-\x{7ff}])(\C)(\C) |
+              (?=[\x{800}-\x{ffff}])(\C)(\C)(\C) |
+              (?=[\x{10000}-\x{1fffff}])(\C)(\C)(\C)(\C))
+        A group that starts with (?| resets the capturing  parentheses  numbers
+        in  each  alternative  (see  "Duplicate Subpattern Numbers" below). The
+        assertions at the start of each branch check the next  UTF-8  character
+        for  values  whose encoding uses 1, 2, 3, or 4 bytes, respectively. The
+        character's individual bytes are then captured by the appropriate  num-
+        ber of groups.
  SQUARE BRACKETS AND CHARACTER CLASSES
-Line 4162 
 SQUARE BRACKETS AND CHARACTER CLASSES
+Line 4180 
 SQUARE BRACKETS AND CHARACTER CLASSES
         closing square bracket. A closing square bracket on its own is not spe-
         cial by default.  However, if the PCRE_JAVASCRIPT_COMPAT option is set,
         a lone closing square bracket causes a compile-time error. If a closing
-        square bracket is required as a member of the class, it should  be  the
+        square  bracket  is required as a member of the class, it should be the
-        first  data  character  in  the  class (after an initial circumflex, if
+        first data character in the class  (after  an  initial  circumflex,  if
         present) or escaped with a backslash.
-        A character class matches a single character in the subject.  In  UTF-8
+        A  character  class matches a single character in the subject. In UTF-8
         mode, the character may be more than one byte long. A matched character
         must be in the set of characters defined by the class, unless the first
-        character  in  the  class definition is a circumflex, in which case the
+        character in the class definition is a circumflex, in  which  case  the
-        subject character must not be in the set defined by  the  class.  If  a
+        subject  character  must  not  be in the set defined by the class. If a
-        circumflex  is actually required as a member of the class, ensure it is
+        circumflex is actually required as a member of the class, ensure it  is
         not the first character, or escape it with a backslash.
-        For example, the character class [aeiou] matches any lower case  vowel,
+        For  example, the character class [aeiou] matches any lower case vowel,
-        while  [^aeiou]  matches  any character that is not a lower case vowel.
+        while [^aeiou] matches any character that is not a  lower  case  vowel.
         Note that a circumflex is just a convenient notation for specifying the
-        characters  that  are in the class by enumerating those that are not. A
+        characters that are in the class by enumerating those that are  not.  A
-        class that starts with a circumflex is not an assertion; it still  con-
+        class  that starts with a circumflex is not an assertion; it still con-
-        sumes  a  character  from the subject string, and therefore it fails if
+        sumes a character from the subject string, and therefore  it  fails  if
         the current pointer is at the end of the string.
-        In UTF-8 mode, characters with values greater than 255 can be  included
+        In  UTF-8 mode, characters with values greater than 255 can be included
-        in  a  class as a literal string of bytes, or by using the \x{ escaping
+        in a class as a literal string of bytes, or by using the  \x{  escaping
         mechanism.
-        When caseless matching is set, any letters in a  class  represent  both
+        When  caseless  matching  is set, any letters in a class represent both
-        their  upper  case  and lower case versions, so for example, a caseless
+        their upper case and lower case versions, so for  example,  a  caseless
-        [aeiou] matches "A" as well as "a", and a caseless  [^aeiou]  does  not
+        [aeiou]  matches  "A"  as well as "a", and a caseless [^aeiou] does not
-        match  "A", whereas a caseful version would. In UTF-8 mode, PCRE always
+        match "A", whereas a caseful version would. In UTF-8 mode, PCRE  always
-        understands the concept of case for characters whose  values  are  less
+        understands  the  concept  of case for characters whose values are less
-        than  128, so caseless matching is always possible. For characters with
+        than 128, so caseless matching is always possible. For characters  with
-        higher values, the concept of case is supported  if  PCRE  is  compiled
+        higher  values,  the  concept  of case is supported if PCRE is compiled
-        with  Unicode  property support, but not otherwise.  If you want to use
+        with Unicode property support, but not otherwise.  If you want  to  use
-        caseless matching in UTF8-mode for characters 128 and above,  you  must
+        caseless  matching  in UTF8-mode for characters 128 and above, you must
-        ensure  that  PCRE is compiled with Unicode property support as well as
+        ensure that PCRE is compiled with Unicode property support as  well  as
         with UTF-8 support.
-        Characters that might indicate line breaks are  never  treated  in  any
+        Characters  that  might  indicate  line breaks are never treated in any
-        special  way  when  matching  character  classes,  whatever line-ending
+        special way  when  matching  character  classes,  whatever  line-ending
-        sequence is in  use,  and  whatever  setting  of  the  PCRE_DOTALL  and
+        sequence  is  in  use,  and  whatever  setting  of  the PCRE_DOTALL and
         PCRE_MULTILINE options is used. A class such as [^a] always matches one
         of these characters.
-        The minus (hyphen) character can be used to specify a range of  charac-
+        The  minus (hyphen) character can be used to specify a range of charac-
-        ters  in  a  character  class.  For  example,  [d-m] matches any letter
+        ters in a character  class.  For  example,  [d-m]  matches  any  letter
-        between d and m, inclusive. If a  minus  character  is  required  in  a
+        between  d  and  m,  inclusive.  If  a minus character is required in a
-        class,  it  must  be  escaped  with a backslash or appear in a position
+        class, it must be escaped with a backslash  or  appear  in  a  position
-        where it cannot be interpreted as indicating a range, typically as  the
+        where  it cannot be interpreted as indicating a range, typically as the
         first or last character in the class.
         It is not possible to have the literal character "]" as the end charac-
-        ter of a range. A pattern such as [W-]46] is interpreted as a class  of
+        ter  of a range. A pattern such as [W-]46] is interpreted as a class of
-        two  characters ("W" and "-") followed by a literal string "46]", so it
+        two characters ("W" and "-") followed by a literal string "46]", so  it
-        would match "W46]" or "-46]". However, if the "]"  is  escaped  with  a
+        would  match  "W46]"  or  "-46]". However, if the "]" is escaped with a
-        backslash  it is interpreted as the end of range, so [W-\]46] is inter-
+        backslash it is interpreted as the end of range, so [W-\]46] is  inter-
-        preted as a class containing a range followed by two other  characters.
+        preted  as a class containing a range followed by two other characters.
-        The  octal or hexadecimal representation of "]" can also be used to end
+        The octal or hexadecimal representation of "]" can also be used to  end
         a range.
-        Ranges operate in the collating sequence of character values. They  can
+        Ranges  operate in the collating sequence of character values. They can
-        also   be  used  for  characters  specified  numerically,  for  example
+        also  be  used  for  characters  specified  numerically,  for   example
-        [\000-\037]. In UTF-8 mode, ranges can include characters whose  values
+        [\000-\037].  In UTF-8 mode, ranges can include characters whose values
         are greater than 255, for example [\x{100}-\x{2ff}].
         If a range that includes letters is used when caseless matching is set,
         it matches the letters in either case. For example, [W-c] is equivalent
-        to  [][\\^_`wxyzabc],  matched  caselessly,  and  in non-UTF-8 mode, if
+        to [][\\^_`wxyzabc], matched caselessly,  and  in  non-UTF-8  mode,  if
-        character tables for a French locale are in  use,  [\xc8-\xcb]  matches
+        character  tables  for  a French locale are in use, [\xc8-\xcb] matches
-        accented  E  characters in both cases. In UTF-8 mode, PCRE supports the
+        accented E characters in both cases. In UTF-8 mode, PCRE  supports  the
-        concept of case for characters with values greater than 128  only  when
+        concept  of  case for characters with values greater than 128 only when
         it is compiled with Unicode property support.
-        The  character escape sequences \d, \D, \h, \H, \p, \P, \s, \S, \v, \V,
+        The character escape sequences \d, \D, \h, \H, \p, \P, \s, \S, \v,  \V,
         \w, and \W may appear in a character class, and add the characters that
-        they  match to the class. For example, [\dABCDEF] matches any hexadeci-
+        they match to the class. For example, [\dABCDEF] matches any  hexadeci-
-        mal digit. In UTF-8 mode, the PCRE_UCP option affects the  meanings  of
+        mal  digit.  In UTF-8 mode, the PCRE_UCP option affects the meanings of
-        \d,  \s,  \w  and  their upper case partners, just as it does when they
+        \d, \s, \w and their upper case partners, just as  it  does  when  they
-        appear outside a character class, as described in the section  entitled
+        appear  outside a character class, as described in the section entitled
         "Generic character types" above. The escape sequence \b has a different
-        meaning inside a character class; it matches the  backspace  character.
+        meaning  inside  a character class; it matches the backspace character.
-        The  sequences  \B,  \N,  \R, and \X are not special inside a character
+        The sequences \B, \N, \R, and \X are not  special  inside  a  character
-        class. Like any other unrecognized escape sequences, they  are  treated
+        class.  Like  any other unrecognized escape sequences, they are treated
-        as  the literal characters "B", "N", "R", and "X" by default, but cause
+        as the literal characters "B", "N", "R", and "X" by default, but  cause
         an error if the PCRE_EXTRA option is set.
-        A circumflex can conveniently be used with  the  upper  case  character
+        A  circumflex  can  conveniently  be used with the upper case character
-        types  to specify a more restricted set of characters than the matching
+        types to specify a more restricted set of characters than the  matching
-        lower case type.  For example, the class [^\W_] matches any  letter  or
+        lower  case  type.  For example, the class [^\W_] matches any letter or
         digit, but not underscore, whereas [\w] includes underscore. A positive
         character class should be read as "something OR something OR ..." and a
         negative class as "NOT something AND NOT something AND NOT ...".
-        The  only  metacharacters  that are recognized in character classes are
+        The only metacharacters that are recognized in  character  classes  are
-        backslash, hyphen (only where it can be  interpreted  as  specifying  a
+        backslash,  hyphen  (only  where  it can be interpreted as specifying a
-        range),  circumflex  (only  at the start), opening square bracket (only
+        range), circumflex (only at the start), opening  square  bracket  (only
-        when it can be interpreted as introducing a POSIX class name - see  the
+        when  it can be interpreted as introducing a POSIX class name - see the
-        next  section),  and  the  terminating closing square bracket. However,
+        next section), and the terminating  closing  square  bracket.  However,
         escaping other non-alphanumeric characters does no harm.
  POSIX CHARACTER CLASSES
         Perl supports the POSIX notation for character classes. This uses names
-        enclosed  by  [: and :] within the enclosing square brackets. PCRE also
+        enclosed by [: and :] within the enclosing square brackets.  PCRE  also
         supports this notation. For example,
           [01[:alpha:]%]
-Line 4287 
 POSIX CHARACTER CLASSES
+Line 4305 
 POSIX CHARACTER CLASSES
           word     "word" characters (same as \w)
           xdigit   hexadecimal digits
-        The  "space" characters are HT (9), LF (10), VT (11), FF (12), CR (13),
+        The "space" characters are HT (9), LF (10), VT (11), FF (12), CR  (13),
-        and space (32). Notice that this list includes the VT  character  (code
+        and  space  (32). Notice that this list includes the VT character (code
 ). This makes "space" different to \s, which does not include VT (for
         Perl compatibility).
-        The name "word" is a Perl extension, and "blank"  is  a  GNU  extension
+        The  name  "word"  is  a Perl extension, and "blank" is a GNU extension
-        from  Perl  5.8. Another Perl extension is negation, which is indicated
+        from Perl 5.8. Another Perl extension is negation, which  is  indicated
         by a ^ character after the colon. For example,
           [12[:^digit:]]
-        matches "1", "2", or any non-digit. PCRE (and Perl) also recognize  the
+        matches  "1", "2", or any non-digit. PCRE (and Perl) also recognize the
         POSIX syntax [.ch.] and [=ch=] where "ch" is a "collating element", but
         these are not supported, and an error is given if they are encountered.
-        By default, in UTF-8 mode, characters with values greater than  128  do
+        By  default,  in UTF-8 mode, characters with values greater than 128 do
-        not  match any of the POSIX character classes. However, if the PCRE_UCP
+        not match any of the POSIX character classes. However, if the  PCRE_UCP
-        option is passed to pcre_compile(), some of the classes are changed  so
+        option  is passed to pcre_compile(), some of the classes are changed so
         that Unicode character properties are used. This is achieved by replac-
         ing the POSIX classes by other sequences, as follows:
-Line 4317 
 POSIX CHARACTER CLASSES
+Line 4335 
 POSIX CHARACTER CLASSES
           [:upper:]  becomes  \p{Lu}
           [:word:]   becomes  \p{Xwd}
-        Negated versions, such as [:^alpha:] use \P instead of  \p.  The  other
+        Negated  versions,  such  as [:^alpha:] use \P instead of \p. The other
         POSIX classes are unchanged, and match only characters with code points
         less than 128.
  VERTICAL BAR
-        Vertical bar characters are used to separate alternative patterns.  For
+        Vertical  bar characters are used to separate alternative patterns. For
         example, the pattern
           gilbert|sullivan
-        matches  either "gilbert" or "sullivan". Any number of alternatives may
+        matches either "gilbert" or "sullivan". Any number of alternatives  may
-        appear, and an empty  alternative  is  permitted  (matching  the  empty
+        appear,  and  an  empty  alternative  is  permitted (matching the empty
         string). The matching process tries each alternative in turn, from left
-        to right, and the first one that succeeds is used. If the  alternatives
+        to  right, and the first one that succeeds is used. If the alternatives
-        are  within a subpattern (defined below), "succeeds" means matching the
+        are within a subpattern (defined below), "succeeds" means matching  the
         rest of the main pattern as well as the alternative in the subpattern.
  INTERNAL OPTION SETTING
-        The settings of the  PCRE_CASELESS,  PCRE_MULTILINE,  PCRE_DOTALL,  and
+        The  settings  of  the  PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, and
-        PCRE_EXTENDED  options  (which are Perl-compatible) can be changed from
+        PCRE_EXTENDED options (which are Perl-compatible) can be  changed  from
-        within the pattern by  a  sequence  of  Perl  option  letters  enclosed
+        within  the  pattern  by  a  sequence  of  Perl option letters enclosed
         between "(?" and ")".  The option letters are
           i  for PCRE_CASELESS
-Line 4351 
 INTERNAL OPTION SETTING
+Line 4369 
 INTERNAL OPTION SETTING
         For example, (?im) sets caseless, multiline matching. It is also possi-
         ble to unset these options by preceding the letter with a hyphen, and a
-        combined  setting and unsetting such as (?im-sx), which sets PCRE_CASE-
+        combined setting and unsetting such as (?im-sx), which sets  PCRE_CASE-
-        LESS and PCRE_MULTILINE while unsetting PCRE_DOTALL and  PCRE_EXTENDED,
+        LESS  and PCRE_MULTILINE while unsetting PCRE_DOTALL and PCRE_EXTENDED,
-        is  also  permitted.  If  a  letter  appears  both before and after the
+        is also permitted. If a  letter  appears  both  before  and  after  the
         hyphen, the option is unset.
-        The PCRE-specific options PCRE_DUPNAMES, PCRE_UNGREEDY, and  PCRE_EXTRA
+        The  PCRE-specific options PCRE_DUPNAMES, PCRE_UNGREEDY, and PCRE_EXTRA
-        can  be changed in the same way as the Perl-compatible options by using
+        can be changed in the same way as the Perl-compatible options by  using
         the characters J, U and X respectively.
-        When one of these option changes occurs at  top  level  (that  is,  not
+        When  one  of  these  option  changes occurs at top level (that is, not
-        inside  subpattern parentheses), the change applies to the remainder of
+        inside subpattern parentheses), the change applies to the remainder  of
         the pattern that follows. If the change is placed right at the start of
         a pattern, PCRE extracts it into the global options (and it will there-
         fore show up in data extracted by the pcre_fullinfo() function).
-        An option change within a subpattern (see below for  a  description  of
+        An  option  change  within a subpattern (see below for a description of
-        subpatterns)  affects only that part of the subpattern that follows it,
+        subpatterns) affects only that part of the subpattern that follows  it,
         so
           (a(?i)b)c
         matches abc and aBc and no other strings (assuming PCRE_CASELESS is not
-        used).   By  this means, options can be made to have different settings
+        used).  By this means, options can be made to have  different  settings
-        in different parts of the pattern. Any changes made in one  alternative
+        in  different parts of the pattern. Any changes made in one alternative
-        do  carry  on  into subsequent branches within the same subpattern. For
+        do carry on into subsequent branches within the  same  subpattern.  For
         example,
           (a(?i)b|c)
-        matches "ab", "aB", "c", and "C", even though  when  matching  "C"  the
+        matches  "ab",  "aB",  "c",  and "C", even though when matching "C" the
-        first  branch  is  abandoned before the option setting. This is because
+        first branch is abandoned before the option setting.  This  is  because
-        the effects of option settings happen at compile time. There  would  be
+        the  effects  of option settings happen at compile time. There would be
         some very weird behaviour otherwise.
-        Note:  There  are  other  PCRE-specific  options that can be set by the
+        Note: There are other PCRE-specific options that  can  be  set  by  the
-        application when the compile or match functions  are  called.  In  some
+        application  when  the  compile  or match functions are called. In some
         cases the pattern can contain special leading sequences such as (*CRLF)
-        to override what the application has set or what  has  been  defaulted.
+        to  override  what  the application has set or what has been defaulted.
-        Details  are  given  in the section entitled "Newline sequences" above.
+        Details are given in the section entitled  "Newline  sequences"  above.
-        There are also the (*UTF8) and (*UCP) leading  sequences  that  can  be
+        There  are  also  the  (*UTF8) and (*UCP) leading sequences that can be
-        used  to  set  UTF-8 and Unicode property modes; they are equivalent to
+        used to set UTF-8 and Unicode property modes; they  are  equivalent  to
         setting the PCRE_UTF8 and the PCRE_UCP options, respectively.
-Line 4404 
 SUBPATTERNS
+Line 4422 
 SUBPATTERNS
           cat(aract|erpillar|)
-        matches  "cataract",  "caterpillar", or "cat". Without the parentheses,
+        matches "cataract", "caterpillar", or "cat". Without  the  parentheses,
         it would match "cataract", "erpillar" or an empty string.
-. It sets up the subpattern as  a  capturing  subpattern.  This  means
+.  It  sets  up  the  subpattern as a capturing subpattern. This means
-        that,  when  the  whole  pattern  matches,  that portion of the subject
+        that, when the whole pattern  matches,  that  portion  of  the  subject
         string that matched the subpattern is passed back to the caller via the
-        ovector  argument  of pcre_exec(). Opening parentheses are counted from
+        ovector argument of pcre_exec(). Opening parentheses are  counted  from
-        left to right (starting from 1) to obtain  numbers  for  the  capturing
+        left  to  right  (starting  from 1) to obtain numbers for the capturing
-        subpatterns.  For  example,  if  the  string  "the red king" is matched
+        subpatterns. For example, if the  string  "the  red  king"  is  matched
         against the pattern
           the ((red|white) (king|queen))
-Line 4420 
 SUBPATTERNS
+Line 4438 
 SUBPATTERNS
         the captured substrings are "red king", "red", and "king", and are num-
         bered 1, 2, and 3, respectively.
-        The  fact  that  plain  parentheses  fulfil two functions is not always
+        The fact that plain parentheses fulfil  two  functions  is  not  always
-        helpful.  There are often times when a grouping subpattern is  required
+        helpful.   There are often times when a grouping subpattern is required
-        without  a capturing requirement. If an opening parenthesis is followed
+        without a capturing requirement. If an opening parenthesis is  followed
-        by a question mark and a colon, the subpattern does not do any  captur-
+        by  a question mark and a colon, the subpattern does not do any captur-
-        ing,  and  is  not  counted when computing the number of any subsequent
+        ing, and is not counted when computing the  number  of  any  subsequent
-        capturing subpatterns. For example, if the string "the white queen"  is
+        capturing  subpatterns. For example, if the string "the white queen" is
         matched against the pattern
           the ((?:red|white) (king|queen))
-Line 4433 
 SUBPATTERNS
+Line 4451 
 SUBPATTERNS
         the captured substrings are "white queen" and "queen", and are numbered
 and 2. The maximum number of capturing subpatterns is 65535.
-        As a convenient shorthand, if any option settings are required  at  the
+        As  a  convenient shorthand, if any option settings are required at the
-        start  of  a  non-capturing  subpattern,  the option letters may appear
+        start of a non-capturing subpattern,  the  option  letters  may  appear
         between the "?" and the ":". Thus the two patterns
           (?i:saturday|sunday)
           (?:(?i)saturday|sunday)
         match exactly the same set of strings. Because alternative branches are
-        tried  from  left  to right, and options are not reset until the end of
+        tried from left to right, and options are not reset until  the  end  of
-        the subpattern is reached, an option setting in one branch does  affect
+        the  subpattern is reached, an option setting in one branch does affect
-        subsequent  branches,  so  the above patterns match "SUNDAY" as well as
+        subsequent branches, so the above patterns match "SUNDAY"  as  well  as
         "Saturday".
  DUPLICATE SUBPATTERN NUMBERS
         Perl 5.10 introduced a feature whereby each alternative in a subpattern
-        uses  the same numbers for its capturing parentheses. Such a subpattern
+        uses the same numbers for its capturing parentheses. Such a  subpattern
-        starts with (?| and is itself a non-capturing subpattern. For  example,
+        starts  with (?| and is itself a non-capturing subpattern. For example,
         consider this pattern:
           (?|(Sat)ur|(Sun))day
-        Because  the two alternatives are inside a (?| group, both sets of cap-
+        Because the two alternatives are inside a (?| group, both sets of  cap-
-        turing parentheses are numbered one. Thus, when  the  pattern  matches,
+        turing  parentheses  are  numbered one. Thus, when the pattern matches,
-        you  can  look  at captured substring number one, whichever alternative
+        you can look at captured substring number  one,  whichever  alternative
-        matched. This construct is useful when you want to  capture  part,  but
+        matched.  This  construct  is useful when you want to capture part, but
         not all, of one of a number of alternatives. Inside a (?| group, paren-
-        theses are numbered as usual, but the number is reset at the  start  of
+        theses  are  numbered as usual, but the number is reset at the start of
-        each  branch.  The numbers of any capturing parentheses that follow the
+        each branch. The numbers of any capturing parentheses that  follow  the
-        subpattern start after the highest number used in any branch. The  fol-
+        subpattern  start after the highest number used in any branch. The fol-
         lowing example is taken from the Perl documentation. The numbers under-
         neath show in which buffer the captured content will be stored.
-Line 4471 
 DUPLICATE SUBPATTERN NUMBERS
+Line 4489 
 DUPLICATE SUBPATTERN NUMBERS
           / ( a )  (?| x ( y ) z | (p (q) r) | (t) u (v) ) ( z ) /x
           # 1            2         2  3        2     3     4
-        A back reference to a numbered subpattern uses the  most  recent  value
+        A  back  reference  to a numbered subpattern uses the most recent value
-        that  is  set  for that number by any subpattern. The following pattern
+        that is set for that number by any subpattern.  The  following  pattern
         matches "abcabc" or "defdef":
           /(?|(abc)|(def))\1/
-        In contrast, a recursive or "subroutine" call to a numbered  subpattern
+        In  contrast,  a subroutine call to a numbered subpattern always refers
-        always  refers  to  the first one in the pattern with the given number.
+        to the first one in the pattern with the given  number.  The  following
-        The following pattern matches "abcabc" or "defabc":
+        pattern matches "abcabc" or "defabc":
           /(?|(abc)|(def))(?1)/
-        If a condition test for a subpattern's having matched refers to a  non-
+        If  a condition test for a subpattern's having matched refers to a non-
-        unique  number, the test is true if any of the subpatterns of that num-
+        unique number, the test is true if any of the subpatterns of that  num-
         ber have matched.
-        An alternative approach to using this "branch reset" feature is to  use
+        An  alternative approach to using this "branch reset" feature is to use
         duplicate named subpatterns, as described in the next section.
  NAMED SUBPATTERNS
-        Identifying  capturing  parentheses  by number is simple, but it can be
+        Identifying capturing parentheses by number is simple, but  it  can  be
-        very hard to keep track of the numbers in complicated  regular  expres-
+        very  hard  to keep track of the numbers in complicated regular expres-
-        sions.  Furthermore,  if  an  expression  is  modified, the numbers may
+        sions. Furthermore, if an  expression  is  modified,  the  numbers  may
-        change. To help with this difficulty, PCRE supports the naming of  sub-
+        change.  To help with this difficulty, PCRE supports the naming of sub-
         patterns. This feature was not added to Perl until release 5.10. Python
-        had the feature earlier, and PCRE introduced it at release  4.0,  using
+        had  the  feature earlier, and PCRE introduced it at release 4.0, using
-        the  Python syntax. PCRE now supports both the Perl and the Python syn-
+        the Python syntax. PCRE now supports both the Perl and the Python  syn-
-        tax. Perl allows identically numbered  subpatterns  to  have  different
+        tax.  Perl  allows  identically  numbered subpatterns to have different
         names, but PCRE does not.
-        In  PCRE,  a subpattern can be named in one of three ways: (?<name>...)
+        In PCRE, a subpattern can be named in one of three  ways:  (?<name>...)
-        or (?'name'...) as in Perl, or (?P<name>...) as in  Python.  References
+        or  (?'name'...)  as in Perl, or (?P<name>...) as in Python. References
-        to  capturing parentheses from other parts of the pattern, such as back
+        to capturing parentheses from other parts of the pattern, such as  back
-        references, recursion, and conditions, can be made by name as  well  as
+        references,  recursion,  and conditions, can be made by name as well as
         by number.
-        Names  consist  of  up  to  32 alphanumeric characters and underscores.
+        Names consist of up to  32  alphanumeric  characters  and  underscores.
-        Named capturing parentheses are still  allocated  numbers  as  well  as
+        Named  capturing  parentheses  are  still  allocated numbers as well as
-        names,  exactly as if the names were not present. The PCRE API provides
+        names, exactly as if the names were not present. The PCRE API  provides
         function calls for extracting the name-to-number translation table from
         a compiled pattern. There is also a convenience function for extracting
         a captured substring by name.
-        By default, a name must be unique within a pattern, but it is  possible
+        By  default, a name must be unique within a pattern, but it is possible
         to relax this constraint by setting the PCRE_DUPNAMES option at compile
-        time. (Duplicate names are also always permitted for  subpatterns  with
+        time.  (Duplicate  names are also always permitted for subpatterns with
-        the  same  number, set up as described in the previous section.) Dupli-
+        the same number, set up as described in the previous  section.)  Dupli-
-        cate names can be useful for patterns where only one  instance  of  the
+        cate  names  can  be useful for patterns where only one instance of the
-        named  parentheses  can  match. Suppose you want to match the name of a
+        named parentheses can match. Suppose you want to match the  name  of  a
-        weekday, either as a 3-letter abbreviation or as the full name, and  in
+        weekday,  either as a 3-letter abbreviation or as the full name, and in
         both cases you want to extract the abbreviation. This pattern (ignoring
         the line breaks) does the job:
-Line 4532 
 NAMED SUBPATTERNS
+Line 4550 
 NAMED SUBPATTERNS
           (?<DN>Thu)(?:rsday)?|
           (?<DN>Sat)(?:urday)?
-        There are five capturing substrings, but only one is ever set  after  a
+        There  are  five capturing substrings, but only one is ever set after a
         match.  (An alternative way of solving this problem is to use a "branch
         reset" subpattern, as described in the previous section.)
-        The convenience function for extracting the data by  name  returns  the
+        The  convenience  function  for extracting the data by name returns the
-        substring  for  the first (and in this example, the only) subpattern of
+        substring for the first (and in this example, the only)  subpattern  of
-        that name that matched. This saves searching  to  find  which  numbered
+        that  name  that  matched.  This saves searching to find which numbered
         subpattern it was.
-        If  you  make  a  back  reference to a non-unique named subpattern from
+        If you make a back reference to  a  non-unique  named  subpattern  from
-        elsewhere in the pattern, the one that corresponds to the first  occur-
+        elsewhere  in the pattern, the one that corresponds to the first occur-
         rence of the name is used. In the absence of duplicate numbers (see the
-        previous section) this is the one with the lowest number. If you use  a
+        previous  section) this is the one with the lowest number. If you use a
-        named  reference  in a condition test (see the section about conditions
+        named reference in a condition test (see the section  about  conditions
-        below), either to check whether a subpattern has matched, or  to  check
+        below),  either  to check whether a subpattern has matched, or to check
-        for  recursion,  all  subpatterns with the same name are tested. If the
+        for recursion, all subpatterns with the same name are  tested.  If  the
-        condition is true for any one of them, the overall condition  is  true.
+        condition  is  true for any one of them, the overall condition is true.
         This is the same behaviour as testing by number. For further details of
         the interfaces for handling named subpatterns, see the pcreapi documen-
         tation.
         Warning: You cannot use different names to distinguish between two sub-
-        patterns with the same number because PCRE uses only the  numbers  when
+        patterns  with  the same number because PCRE uses only the numbers when
         matching. For this reason, an error is given at compile time if differ-
-        ent names are given to subpatterns with the same number.  However,  you
+        ent  names  are given to subpatterns with the same number. However, you
-        can  give  the same name to subpatterns with the same number, even when
+        can give the same name to subpatterns with the same number,  even  when
         PCRE_DUPNAMES is not set.
  REPETITION
-        Repetition is specified by quantifiers, which can  follow  any  of  the
+        Repetition  is  specified  by  quantifiers, which can follow any of the
         following items:
           a literal data character
-Line 4575 
 REPETITION
+Line 4593 
 REPETITION
           a character class
           a back reference (see next section)
           a parenthesized subpattern (including assertions)
-          a recursive or "subroutine" call to a subpattern
+          a subroutine call to a subpattern (recursive or otherwise)
-        The  general repetition quantifier specifies a minimum and maximum num-
+        The general repetition quantifier specifies a minimum and maximum  num-
-        ber of permitted matches, by giving the two numbers in  curly  brackets
+        ber  of  permitted matches, by giving the two numbers in curly brackets
-        (braces),  separated  by  a comma. The numbers must be less than 65536,
+        (braces), separated by a comma. The numbers must be  less  than  65536,
         and the first must be less than or equal to the second. For example:
           z{2,4}
-        matches "zz", "zzz", or "zzzz". A closing brace on its  own  is  not  a
+        matches  "zz",  "zzz",  or  "zzzz". A closing brace on its own is not a
-        special  character.  If  the second number is omitted, but the comma is
+        special character. If the second number is omitted, but  the  comma  is
-        present, there is no upper limit; if the second number  and  the  comma
+        present,  there  is  no upper limit; if the second number and the comma
-        are  both omitted, the quantifier specifies an exact number of required
+        are both omitted, the quantifier specifies an exact number of  required
         matches. Thus
           [aeiou]{3,}
-Line 4596 
 REPETITION
+Line 4614 
 REPETITION
           \d{8}
-        matches exactly 8 digits. An opening curly bracket that  appears  in  a
+        matches  exactly  8  digits. An opening curly bracket that appears in a
-        position  where a quantifier is not allowed, or one that does not match
+        position where a quantifier is not allowed, or one that does not  match
-        the syntax of a quantifier, is taken as a literal character. For  exam-
+        the  syntax of a quantifier, is taken as a literal character. For exam-
         ple, {,6} is not a quantifier, but a literal string of four characters.
-        In  UTF-8  mode,  quantifiers  apply to UTF-8 characters rather than to
+        In UTF-8 mode, quantifiers apply to UTF-8  characters  rather  than  to
         individual bytes. Thus, for example, \x{100}{2} matches two UTF-8 char-
         acters, each of which is represented by a two-byte sequence. Similarly,
         when Unicode property support is available, \X{3} matches three Unicode
-        extended  sequences,  each of which may be several bytes long (and they
+        extended sequences, each of which may be several bytes long  (and  they
         may be of different lengths).
         The quantifier {0} is permitted, causing the expression to behave as if
         the previous item and the quantifier were not present. This may be use-
-        ful for subpatterns that are referenced as subroutines  from  elsewhere
+        ful  for  subpatterns that are referenced as subroutines from elsewhere
         in the pattern (but see also the section entitled "Defining subpatterns
-        for use by reference only" below). Items other  than  subpatterns  that
+        for  use  by  reference only" below). Items other than subpatterns that
         have a {0} quantifier are omitted from the compiled pattern.
-        For  convenience, the three most common quantifiers have single-charac-
+        For convenience, the three most common quantifiers have  single-charac-
         ter abbreviations:
           *    is equivalent to {0,}
           +    is equivalent to {1,}
           ?    is equivalent to {0,1}
-        It is possible to construct infinite loops by  following  a  subpattern
+        It  is  possible  to construct infinite loops by following a subpattern
         that can match no characters with a quantifier that has no upper limit,
         for example:
           (a?)*
         Earlier versions of Perl and PCRE used to give an error at compile time
-        for  such  patterns. However, because there are cases where this can be
+        for such patterns. However, because there are cases where this  can  be
-        useful, such patterns are now accepted, but if any  repetition  of  the
+        useful,  such  patterns  are now accepted, but if any repetition of the
-        subpattern  does in fact match no characters, the loop is forcibly bro-
+        subpattern does in fact match no characters, the loop is forcibly  bro-
         ken.
-        By default, the quantifiers are "greedy", that is, they match  as  much
+        By  default,  the quantifiers are "greedy", that is, they match as much
-        as  possible  (up  to  the  maximum number of permitted times), without
+        as possible (up to the maximum  number  of  permitted  times),  without
-        causing the rest of the pattern to fail. The classic example  of  where
+        causing  the  rest of the pattern to fail. The classic example of where
         this gives problems is in trying to match comments in C programs. These
-        appear between /* and */ and within the comment,  individual  *  and  /
+        appear  between  /*  and  */ and within the comment, individual * and /
-        characters  may  appear. An attempt to match C comments by applying the
+        characters may appear. An attempt to match C comments by  applying  the
         pattern
           /\*.*\*/
-Line 4648 
 REPETITION
+Line 4666 
 REPETITION
           /* first comment */  not comment  /* second comment */
-        fails, because it matches the entire string owing to the greediness  of
+        fails,  because it matches the entire string owing to the greediness of
         the .*  item.
-        However,  if  a quantifier is followed by a question mark, it ceases to
+        However, if a quantifier is followed by a question mark, it  ceases  to
         be greedy, and instead matches the minimum number of times possible, so
         the pattern
           /\*.*?\*/
-        does  the  right  thing with the C comments. The meaning of the various
+        does the right thing with the C comments. The meaning  of  the  various
-        quantifiers is not otherwise changed,  just  the  preferred  number  of
+        quantifiers  is  not  otherwise  changed,  just the preferred number of
-        matches.   Do  not  confuse this use of question mark with its use as a
+        matches.  Do not confuse this use of question mark with its  use  as  a
-        quantifier in its own right. Because it has two uses, it can  sometimes
+        quantifier  in its own right. Because it has two uses, it can sometimes
         appear doubled, as in
           \d??\d
-Line 4668 
 REPETITION
+Line 4686 
 REPETITION
         which matches one digit by preference, but can match two if that is the
         only way the rest of the pattern matches.
-        If the PCRE_UNGREEDY option is set (an option that is not available  in
+        If  the PCRE_UNGREEDY option is set (an option that is not available in
-        Perl),  the  quantifiers are not greedy by default, but individual ones
+        Perl), the quantifiers are not greedy by default, but  individual  ones
-        can be made greedy by following them with a  question  mark.  In  other
+        can  be  made  greedy  by following them with a question mark. In other
         words, it inverts the default behaviour.
-        When  a  parenthesized  subpattern  is quantified with a minimum repeat
+        When a parenthesized subpattern is quantified  with  a  minimum  repeat
-        count that is greater than 1 or with a limited maximum, more memory  is
+        count  that is greater than 1 or with a limited maximum, more memory is
-        required  for  the  compiled  pattern, in proportion to the size of the
+        required for the compiled pattern, in proportion to  the  size  of  the
         minimum or maximum.
         If a pattern starts with .* or .{0,} and the PCRE_DOTALL option (equiv-
-        alent  to  Perl's  /s) is set, thus allowing the dot to match newlines,
+        alent to Perl's /s) is set, thus allowing the dot  to  match  newlines,
-        the pattern is implicitly anchored, because whatever  follows  will  be
+        the  pattern  is  implicitly anchored, because whatever follows will be
-        tried  against every character position in the subject string, so there
+        tried against every character position in the subject string, so  there
-        is no point in retrying the overall match at  any  position  after  the
+        is  no  point  in  retrying the overall match at any position after the
-        first.  PCRE  normally treats such a pattern as though it were preceded
+        first. PCRE normally treats such a pattern as though it  were  preceded
         by \A.
-        In cases where it is known that the subject  string  contains  no  new-
+        In  cases  where  it  is known that the subject string contains no new-
-        lines,  it  is  worth setting PCRE_DOTALL in order to obtain this opti-
+        lines, it is worth setting PCRE_DOTALL in order to  obtain  this  opti-
         mization, or alternatively using ^ to indicate anchoring explicitly.
-        However, there is one situation where the optimization cannot be  used.
+        However,  there is one situation where the optimization cannot be used.
         When .*  is inside capturing parentheses that are the subject of a back
         reference elsewhere in the pattern, a match at the start may fail where
         a later one succeeds. Consider, for example:
           (.*)abc\1
-        If  the subject is "xyz123abc123" the match point is the fourth charac-
+        If the subject is "xyz123abc123" the match point is the fourth  charac-
         ter. For this reason, such a pattern is not implicitly anchored.
         When a capturing subpattern is repeated, the value captured is the sub-
-Line 4706 
 REPETITION
+Line 4724 
 REPETITION
           (tweedle[dume]{3}\s*)+
         has matched "tweedledum tweedledee" the value of the captured substring
-        is "tweedledee". However, if there are  nested  capturing  subpatterns,
+        is  "tweedledee".  However,  if there are nested capturing subpatterns,
-        the  corresponding captured values may have been set in previous itera-
+        the corresponding captured values may have been set in previous  itera-
         tions. For example, after
           /(a|(b))+/
-Line 4717 
 REPETITION
+Line 4735 
 REPETITION
  ATOMIC GROUPING AND POSSESSIVE QUANTIFIERS
-        With both maximizing ("greedy") and minimizing ("ungreedy"  or  "lazy")
+        With  both  maximizing ("greedy") and minimizing ("ungreedy" or "lazy")
-        repetition,  failure  of what follows normally causes the repeated item
+        repetition, failure of what follows normally causes the  repeated  item
-        to be re-evaluated to see if a different number of repeats  allows  the
+        to  be  re-evaluated to see if a different number of repeats allows the
-        rest  of  the pattern to match. Sometimes it is useful to prevent this,
+        rest of the pattern to match. Sometimes it is useful to  prevent  this,
-        either to change the nature of the match, or to cause it  fail  earlier
+        either  to  change the nature of the match, or to cause it fail earlier
-        than  it otherwise might, when the author of the pattern knows there is
+        than it otherwise might, when the author of the pattern knows there  is
         no point in carrying on.
-        Consider, for example, the pattern \d+foo when applied to  the  subject
+        Consider,  for  example, the pattern \d+foo when applied to the subject
         line
 bar
         After matching all 6 digits and then failing to match "foo", the normal
-        action of the matcher is to try again with only 5 digits  matching  the
+        action  of  the matcher is to try again with only 5 digits matching the
-        \d+  item,  and  then  with  4,  and  so on, before ultimately failing.
+        \d+ item, and then with  4,  and  so  on,  before  ultimately  failing.
-        "Atomic grouping" (a term taken from Jeffrey  Friedl's  book)  provides
+        "Atomic  grouping"  (a  term taken from Jeffrey Friedl's book) provides
-        the  means for specifying that once a subpattern has matched, it is not
+        the means for specifying that once a subpattern has matched, it is  not
         to be re-evaluated in this way.
-        If we use atomic grouping for the previous example, the  matcher  gives
+        If  we  use atomic grouping for the previous example, the matcher gives
-        up  immediately  on failing to match "foo" the first time. The notation
+        up immediately on failing to match "foo" the first time.  The  notation
         is a kind of special parenthesis, starting with (?> as in this example:
           (?>\d+)foo
-        This kind of parenthesis "locks up" the  part of the  pattern  it  con-
+        This  kind  of  parenthesis "locks up" the  part of the pattern it con-
-        tains  once  it  has matched, and a failure further into the pattern is
+        tains once it has matched, and a failure further into  the  pattern  is
-        prevented from backtracking into it. Backtracking past it  to  previous
+        prevented  from  backtracking into it. Backtracking past it to previous
         items, however, works as normal.
-        An  alternative  description  is that a subpattern of this type matches
+        An alternative description is that a subpattern of  this  type  matches
-        the string of characters that an  identical  standalone  pattern  would
+        the  string  of  characters  that an identical standalone pattern would
         match, if anchored at the current point in the subject string.
         Atomic grouping subpatterns are not capturing subpatterns. Simple cases
         such as the above example can be thought of as a maximizing repeat that
-        must  swallow  everything  it can. So, while both \d+ and \d+? are pre-
+        must swallow everything it can. So, while both \d+ and  \d+?  are  pre-
-        pared to adjust the number of digits they match in order  to  make  the
+        pared  to  adjust  the number of digits they match in order to make the
         rest of the pattern match, (?>\d+) can only match an entire sequence of
         digits.
-        Atomic groups in general can of course contain arbitrarily  complicated
+        Atomic  groups in general can of course contain arbitrarily complicated
-        subpatterns,  and  can  be  nested. However, when the subpattern for an
+        subpatterns, and can be nested. However, when  the  subpattern  for  an
         atomic group is just a single repeated item, as in the example above, a
-        simpler  notation,  called  a "possessive quantifier" can be used. This
+        simpler notation, called a "possessive quantifier" can  be  used.  This
-        consists of an additional + character  following  a  quantifier.  Using
+        consists  of  an  additional  + character following a quantifier. Using
         this notation, the previous example can be rewritten as
           \d++foo
-Line 4773 
 ATOMIC GROUPING AND POSSESSIVE QUANTIFIE
+Line 4791 
 ATOMIC GROUPING AND POSSESSIVE QUANTIFIE
           (abc|xyz){2,3}+
-        Possessive  quantifiers  are  always  greedy;  the   setting   of   the
+        Possessive   quantifiers   are   always  greedy;  the  setting  of  the
         PCRE_UNGREEDY option is ignored. They are a convenient notation for the
-        simpler forms of atomic group. However, there is no difference  in  the
+        simpler  forms  of atomic group. However, there is no difference in the
-        meaning  of  a  possessive  quantifier and the equivalent atomic group,
+        meaning of a possessive quantifier and  the  equivalent  atomic  group,
-        though there may be a performance  difference;  possessive  quantifiers
+        though  there  may  be a performance difference; possessive quantifiers
         should be slightly faster.
-        The  possessive  quantifier syntax is an extension to the Perl 5.8 syn-
+        The possessive quantifier syntax is an extension to the Perl  5.8  syn-
-        tax.  Jeffrey Friedl originated the idea (and the name)  in  the  first
+        tax.   Jeffrey  Friedl  originated the idea (and the name) in the first
         edition of his book. Mike McCloskey liked it, so implemented it when he
-        built Sun's Java package, and PCRE copied it from there. It  ultimately
+        built  Sun's Java package, and PCRE copied it from there. It ultimately
         found its way into Perl at release 5.10.
         PCRE has an optimization that automatically "possessifies" certain sim-
-        ple pattern constructs. For example, the sequence  A+B  is  treated  as
+        ple  pattern  constructs.  For  example, the sequence A+B is treated as
-        A++B  because  there is no point in backtracking into a sequence of A's
+        A++B because there is no point in backtracking into a sequence  of  A's
         when B must follow.
-        When a pattern contains an unlimited repeat inside  a  subpattern  that
+        When  a  pattern  contains an unlimited repeat inside a subpattern that
-        can  itself  be  repeated  an  unlimited number of times, the use of an
+        can itself be repeated an unlimited number of  times,  the  use  of  an
-        atomic group is the only way to avoid some  failing  matches  taking  a
+        atomic  group  is  the  only way to avoid some failing matches taking a
         very long time indeed. The pattern
           (\D+|<\d+>)*[!?]
-        matches  an  unlimited number of substrings that either consist of non-
+        matches an unlimited number of substrings that either consist  of  non-
-        digits, or digits enclosed in <>, followed by either ! or  ?.  When  it
+        digits,  or  digits  enclosed in <>, followed by either ! or ?. When it
         matches, it runs quickly. However, if it is applied to
           aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
-        it  takes  a  long  time  before reporting failure. This is because the
+        it takes a long time before reporting  failure.  This  is  because  the
-        string can be divided between the internal \D+ repeat and the  external
+        string  can be divided between the internal \D+ repeat and the external
-        *  repeat  in  a  large  number of ways, and all have to be tried. (The
+        * repeat in a large number of ways, and all  have  to  be  tried.  (The
-        example uses [!?] rather than a single character at  the  end,  because
+        example  uses  [!?]  rather than a single character at the end, because
-        both  PCRE  and  Perl have an optimization that allows for fast failure
+        both PCRE and Perl have an optimization that allows  for  fast  failure
-        when a single character is used. They remember the last single  charac-
+        when  a single character is used. They remember the last single charac-
-        ter  that  is required for a match, and fail early if it is not present
+        ter that is required for a match, and fail early if it is  not  present
-        in the string.) If the pattern is changed so that  it  uses  an  atomic
+        in  the  string.)  If  the pattern is changed so that it uses an atomic
         group, like this:
           ((?>\D+)|<\d+>)*[!?]
-Line 4823 
 BACK REFERENCES
+Line 4841 
 BACK REFERENCES
         Outside a character class, a backslash followed by a digit greater than
 (and possibly further digits) is a back reference to a capturing sub-
-        pattern  earlier  (that is, to its left) in the pattern, provided there
+        pattern earlier (that is, to its left) in the pattern,  provided  there
         have been that many previous capturing left parentheses.
         However, if the decimal number following the backslash is less than 10,
-        it  is  always  taken  as a back reference, and causes an error only if
+        it is always taken as a back reference, and causes  an  error  only  if
-        there are not that many capturing left parentheses in the  entire  pat-
+        there  are  not that many capturing left parentheses in the entire pat-
-        tern.  In  other words, the parentheses that are referenced need not be
+        tern. In other words, the parentheses that are referenced need  not  be
-        to the left of the reference for numbers less than 10. A "forward  back
+        to  the left of the reference for numbers less than 10. A "forward back
-        reference"  of  this  type can make sense when a repetition is involved
+        reference" of this type can make sense when a  repetition  is  involved
-        and the subpattern to the right has participated in an  earlier  itera-
+        and  the  subpattern to the right has participated in an earlier itera-
         tion.
-        It  is  not  possible to have a numerical "forward back reference" to a
+        It is not possible to have a numerical "forward back  reference"  to  a
-        subpattern whose number is 10 or  more  using  this  syntax  because  a
+        subpattern  whose  number  is  10  or  more using this syntax because a
-        sequence  such  as  \50 is interpreted as a character defined in octal.
+        sequence such as \50 is interpreted as a character  defined  in  octal.
         See the subsection entitled "Non-printing characters" above for further
-        details  of  the  handling of digits following a backslash. There is no
+        details of the handling of digits following a backslash.  There  is  no
-        such problem when named parentheses are used. A back reference  to  any
+        such  problem  when named parentheses are used. A back reference to any
         subpattern is possible using named parentheses (see below).
-        Another  way  of  avoiding  the ambiguity inherent in the use of digits
+        Another way of avoiding the ambiguity inherent in  the  use  of  digits
-        following a backslash is to use the \g  escape  sequence.  This  escape
+        following  a  backslash  is  to use the \g escape sequence. This escape
         must be followed by an unsigned number or a negative number, optionally
         enclosed in braces. These examples are all identical:
-Line 4852 
 BACK REFERENCES
+Line 4870 
 BACK REFERENCES
           (ring), \g1
           (ring), \g{1}
-        An unsigned number specifies an absolute reference without the  ambigu-
+        An  unsigned number specifies an absolute reference without the ambigu-
         ity that is present in the older syntax. It is also useful when literal
         digits follow the reference. A negative number is a relative reference.
         Consider this example:
-Line 4861 
 BACK REFERENCES
+Line 4879 
 BACK REFERENCES
         The sequence \g{-1} is a reference to the most recently started captur-
         ing subpattern before \g, that is, is it equivalent to \2 in this exam-
-        ple.   Similarly, \g{-2} would be equivalent to \1. The use of relative
+        ple.  Similarly, \g{-2} would be equivalent to \1. The use of  relative
-        references can be helpful in long patterns, and also in  patterns  that
+        references  can  be helpful in long patterns, and also in patterns that
-        are  created  by  joining  together  fragments  that contain references
+        are created by  joining  together  fragments  that  contain  references
         within themselves.
-        A back reference matches whatever actually matched the  capturing  sub-
+        A  back  reference matches whatever actually matched the capturing sub-
-        pattern  in  the  current subject string, rather than anything matching
+        pattern in the current subject string, rather  than  anything  matching
         the subpattern itself (see "Subpatterns as subroutines" below for a way
         of doing that). So the pattern
           (sens|respons)e and \1ibility
-        matches  "sense and sensibility" and "response and responsibility", but
+        matches "sense and sensibility" and "response and responsibility",  but
-        not "sense and responsibility". If caseful matching is in force at  the
+        not  "sense and responsibility". If caseful matching is in force at the
-        time  of the back reference, the case of letters is relevant. For exam-
+        time of the back reference, the case of letters is relevant. For  exam-
         ple,
           ((?i)rah)\s+\1
-        matches "rah rah" and "RAH RAH", but not "RAH  rah",  even  though  the
+        matches  "rah  rah"  and  "RAH RAH", but not "RAH rah", even though the
         original capturing subpattern is matched caselessly.
-        There  are  several  different ways of writing back references to named
+        There are several different ways of writing back  references  to  named
-        subpatterns. The .NET syntax \k{name} and the Perl syntax  \k<name>  or
+        subpatterns.  The  .NET syntax \k{name} and the Perl syntax \k<name> or
-        \k'name'  are supported, as is the Python syntax (?P=name). Perl 5.10's
+        \k'name' are supported, as is the Python syntax (?P=name). Perl  5.10's
         unified back reference syntax, in which \g can be used for both numeric
-        and  named  references,  is  also supported. We could rewrite the above
+        and named references, is also supported. We  could  rewrite  the  above
         example in any of the following ways:
           (?<p1>(?i)rah)\s+\k<p1>
-Line 4895 
 BACK REFERENCES
+Line 4913 
 BACK REFERENCES
           (?P<p1>(?i)rah)\s+(?P=p1)
           (?<p1>(?i)rah)\s+\g{p1}
-        A subpattern that is referenced by  name  may  appear  in  the  pattern
+        A  subpattern  that  is  referenced  by  name may appear in the pattern
         before or after the reference.
-        There  may be more than one back reference to the same subpattern. If a
+        There may be more than one back reference to the same subpattern. If  a
-        subpattern has not actually been used in a particular match,  any  back
+        subpattern  has  not actually been used in a particular match, any back
         references to it always fail by default. For example, the pattern
           (a|(bc))\2
-        always  fails  if  it starts to match "a" rather than "bc". However, if
+        always fails if it starts to match "a" rather than  "bc".  However,  if
         the PCRE_JAVASCRIPT_COMPAT option is set at compile time, a back refer-
         ence to an unset value matches an empty string.
-        Because  there may be many capturing parentheses in a pattern, all dig-
+        Because there may be many capturing parentheses in a pattern, all  dig-
-        its following a backslash are taken as part of a potential back  refer-
+        its  following a backslash are taken as part of a potential back refer-
-        ence  number.   If  the  pattern continues with a digit character, some
+        ence number.  If the pattern continues with  a  digit  character,  some
-        delimiter must  be  used  to  terminate  the  back  reference.  If  the
+        delimiter  must  be  used  to  terminate  the  back  reference.  If the
         PCRE_EXTENDED option is set, this can be whitespace. Otherwise, the \g{
         syntax or an empty comment (see "Comments" below) can be used.
     Recursive back references
-        A back reference that occurs inside the parentheses to which it  refers
+        A  back reference that occurs inside the parentheses to which it refers
-        fails  when  the subpattern is first used, so, for example, (a\1) never
+        fails when the subpattern is first used, so, for example,  (a\1)  never
-        matches.  However, such references can be useful inside  repeated  sub-
+        matches.   However,  such references can be useful inside repeated sub-
         patterns. For example, the pattern
           (a|b\1)+
         matches any number of "a"s and also "aba", "ababbaa" etc. At each iter-
-        ation of the subpattern,  the  back  reference  matches  the  character
+        ation  of  the  subpattern,  the  back  reference matches the character
-        string  corresponding  to  the previous iteration. In order for this to
+        string corresponding to the previous iteration. In order  for  this  to
-        work, the pattern must be such that the first iteration does  not  need
+        work,  the  pattern must be such that the first iteration does not need
-        to  match the back reference. This can be done using alternation, as in
+        to match the back reference. This can be done using alternation, as  in
         the example above, or by a quantifier with a minimum of zero.
-        Back references of this type cause the group that they reference to  be
+        Back  references of this type cause the group that they reference to be
-        treated  as  an atomic group.  Once the whole group has been matched, a
+        treated as an atomic group.  Once the whole group has been  matched,  a
-        subsequent matching failure cannot cause backtracking into  the  middle
+        subsequent  matching  failure cannot cause backtracking into the middle
         of the group.
  ASSERTIONS
-        An  assertion  is  a  test on the characters following or preceding the
+        An assertion is a test on the characters  following  or  preceding  the
-        current matching point that does not actually consume  any  characters.
+        current  matching  point that does not actually consume any characters.
-        The  simple  assertions  coded  as  \b, \B, \A, \G, \Z, \z, ^ and $ are
+        The simple assertions coded as \b, \B, \A, \G, \Z,  \z,  ^  and  $  are
         described above.
-        More complicated assertions are coded as  subpatterns.  There  are  two
+        More  complicated  assertions  are  coded as subpatterns. There are two
-        kinds:  those  that  look  ahead of the current position in the subject
+        kinds: those that look ahead of the current  position  in  the  subject
-        string, and those that look  behind  it.  An  assertion  subpattern  is
+        string,  and  those  that  look  behind  it. An assertion subpattern is
-        matched  in  the  normal way, except that it does not cause the current
+        matched in the normal way, except that it does not  cause  the  current
         matching position to be changed.
-        Assertion subpatterns are not capturing subpatterns. If such an  asser-
+        Assertion  subpatterns are not capturing subpatterns. If such an asser-
-        tion  contains  capturing  subpatterns within it, these are counted for
+        tion contains capturing subpatterns within it, these  are  counted  for
-        the purposes of numbering the capturing subpatterns in the  whole  pat-
+        the  purposes  of numbering the capturing subpatterns in the whole pat-
-        tern.  However,  substring  capturing  is carried out only for positive
+        tern. However, substring capturing is carried  out  only  for  positive
         assertions, because it does not make sense for negative assertions.
-        For compatibility with Perl, assertion  subpatterns  may  be  repeated;
+        For  compatibility  with  Perl,  assertion subpatterns may be repeated;
-        though  it  makes  no sense to assert the same thing several times, the
+        though it makes no sense to assert the same thing  several  times,  the
-        side effect of capturing parentheses may  occasionally  be  useful.  In
+        side  effect  of  capturing  parentheses may occasionally be useful. In
         practice, there only three cases:
-        (1)  If  the  quantifier  is  {0}, the assertion is never obeyed during
+        (1) If the quantifier is {0}, the  assertion  is  never  obeyed  during
-        matching.  However, it may  contain  internal  capturing  parenthesized
+        matching.   However,  it  may  contain internal capturing parenthesized
         groups that are called from elsewhere via the subroutine mechanism.
-        (2)  If quantifier is {0,n} where n is greater than zero, it is treated
+        (2) If quantifier is {0,n} where n is greater than zero, it is  treated
-        as if it were {0,1}. At run time, the rest  of  the  pattern  match  is
+        as  if  it  were  {0,1}.  At run time, the rest of the pattern match is
         tried with and without the assertion, the order depending on the greed-
         iness of the quantifier.
-        (3) If the minimum repetition is greater than zero, the  quantifier  is
+        (3)  If  the minimum repetition is greater than zero, the quantifier is
-        ignored.   The  assertion  is  obeyed just once when encountered during
+        ignored.  The assertion is obeyed just  once  when  encountered  during
         matching.
     Lookahead assertions
-Line 4981 
 ASSERTIONS
+Line 4999 
 ASSERTIONS
           \w+(?=;)
-        matches  a word followed by a semicolon, but does not include the semi-
+        matches a word followed by a semicolon, but does not include the  semi-
         colon in the match, and
           foo(?!bar)
-        matches any occurrence of "foo" that is not  followed  by  "bar".  Note
+        matches  any  occurrence  of  "foo" that is not followed by "bar". Note
         that the apparently similar pattern
           (?!foo)bar
-        does  not  find  an  occurrence  of "bar" that is preceded by something
+        does not find an occurrence of "bar"  that  is  preceded  by  something
-        other than "foo"; it finds any occurrence of "bar" whatsoever,  because
+        other  than "foo"; it finds any occurrence of "bar" whatsoever, because
         the assertion (?!foo) is always true when the next three characters are
         "bar". A lookbehind assertion is needed to achieve the other effect.
         If you want to force a matching failure at some point in a pattern, the
-        most  convenient  way  to  do  it  is with (?!) because an empty string
+        most convenient way to do it is  with  (?!)  because  an  empty  string
-        always matches, so an assertion that requires there not to be an  empty
+        always  matches, so an assertion that requires there not to be an empty
         string must always fail.  The backtracking control verb (*FAIL) or (*F)
         is a synonym for (?!).
     Lookbehind assertions
-        Lookbehind assertions start with (?<= for positive assertions and  (?<!
+        Lookbehind  assertions start with (?<= for positive assertions and (?<!
         for negative assertions. For example,
           (?<!foo)bar
-        does  find  an  occurrence  of "bar" that is not preceded by "foo". The
+        does find an occurrence of "bar" that is not  preceded  by  "foo".  The
-        contents of a lookbehind assertion are restricted  such  that  all  the
+        contents  of  a  lookbehind  assertion are restricted such that all the
         strings it matches must have a fixed length. However, if there are sev-
-        eral top-level alternatives, they do not all  have  to  have  the  same
+        eral  top-level  alternatives,  they  do  not all have to have the same
         fixed length. Thus
           (?<=bullock|donkey)
-Line 5021 
 ASSERTIONS
+Line 5039 
 ASSERTIONS
           (?<!dogs?|cats?)
-        causes  an  error at compile time. Branches that match different length
+        causes an error at compile time. Branches that match  different  length
-        strings are permitted only at the top level of a lookbehind  assertion.
+        strings  are permitted only at the top level of a lookbehind assertion.
         This is an extension compared with Perl, which requires all branches to
         match the same length of string. An assertion such as
           (?<=ab(c|de))
-        is not permitted, because its single top-level  branch  can  match  two
+        is  not  permitted,  because  its single top-level branch can match two
         different lengths, but it is acceptable to PCRE if rewritten to use two
         top-level branches:
           (?<=abc|abde)
-        In some cases, the escape sequence \K (see above) can be  used  instead
+        In  some  cases, the escape sequence \K (see above) can be used instead
         of a lookbehind assertion to get round the fixed-length restriction.
-        The  implementation  of lookbehind assertions is, for each alternative,
+        The implementation of lookbehind assertions is, for  each  alternative,
-        to temporarily move the current position back by the fixed  length  and
+        to  temporarily  move the current position back by the fixed length and
         then try to match. If there are insufficient characters before the cur-
         rent position, the assertion fails.
         PCRE does not allow the \C escape (which matches a single byte in UTF-8
-        mode)  to appear in lookbehind assertions, because it makes it impossi-
+        mode) to appear in lookbehind assertions, because it makes it  impossi-
-        ble to calculate the length of the lookbehind. The \X and  \R  escapes,
+        ble  to  calculate the length of the lookbehind. The \X and \R escapes,
         which can match different numbers of bytes, are also not permitted.
-        "Subroutine"  calls  (see below) such as (?2) or (?&X) are permitted in
+        "Subroutine" calls (see below) such as (?2) or (?&X) are  permitted  in
-        lookbehinds, as long as the subpattern matches a  fixed-length  string.
+        lookbehinds,  as  long as the subpattern matches a fixed-length string.
         Recursion, however, is not supported.
-        Possessive  quantifiers  can  be  used  in  conjunction with lookbehind
+        Possessive quantifiers can  be  used  in  conjunction  with  lookbehind
         assertions to specify efficient matching of fixed-length strings at the
         end of subject strings. Consider a simple pattern such as
           abcd$
-        when  applied  to  a  long string that does not match. Because matching
+        when applied to a long string that does  not  match.  Because  matching
         proceeds from left to right, PCRE will look for each "a" in the subject
-        and  then  see  if what follows matches the rest of the pattern. If the
+        and then see if what follows matches the rest of the  pattern.  If  the
         pattern is specified as
           ^.*abcd$
-        the initial .* matches the entire string at first, but when this  fails
+        the  initial .* matches the entire string at first, but when this fails
         (because there is no following "a"), it backtracks to match all but the
-        last character, then all but the last two characters, and so  on.  Once
+        last  character,  then all but the last two characters, and so on. Once
-        again  the search for "a" covers the entire string, from right to left,
+        again the search for "a" covers the entire string, from right to  left,
         so we are no better off. However, if the pattern is written as
           ^.*+(?<=abcd)
-        there can be no backtracking for the .*+ item; it can  match  only  the
+        there  can  be  no backtracking for the .*+ item; it can match only the
-        entire  string.  The subsequent lookbehind assertion does a single test
+        entire string. The subsequent lookbehind assertion does a  single  test
-        on the last four characters. If it fails, the match fails  immediately.
+        on  the last four characters. If it fails, the match fails immediately.
-        For  long  strings, this approach makes a significant difference to the
+        For long strings, this approach makes a significant difference  to  the
         processing time.
     Using multiple assertions
-Line 5084 
 ASSERTIONS
+Line 5102 
 ASSERTIONS
           (?<=\d{3})(?<!999)foo
-        matches "foo" preceded by three digits that are not "999". Notice  that
+        matches  "foo" preceded by three digits that are not "999". Notice that
-        each  of  the  assertions is applied independently at the same point in
+        each of the assertions is applied independently at the  same  point  in
-        the subject string. First there is a  check  that  the  previous  three
+        the  subject  string.  First  there  is a check that the previous three
-        characters  are  all  digits,  and  then there is a check that the same
+        characters are all digits, and then there is  a  check  that  the  same
         three characters are not "999".  This pattern does not match "foo" pre-
-        ceded  by  six  characters,  the first of which are digits and the last
+        ceded by six characters, the first of which are  digits  and  the  last
-        three of which are not "999". For example, it  doesn't  match  "123abc-
+        three  of  which  are not "999". For example, it doesn't match "123abc-
         foo". A pattern to do that is
           (?<=\d{3}...)(?<!999)foo
-        This  time  the  first assertion looks at the preceding six characters,
+        This time the first assertion looks at the  preceding  six  characters,
         checking that the first three are digits, and then the second assertion
         checks that the preceding three characters are not "999".
-Line 5103 
 ASSERTIONS
+Line 5121 
 ASSERTIONS
           (?<=(?<!foo)bar)baz
-        matches  an occurrence of "baz" that is preceded by "bar" which in turn
+        matches an occurrence of "baz" that is preceded by "bar" which in  turn
         is not preceded by "foo", while
           (?<=\d{3}(?!999)...)foo
-        is another pattern that matches "foo" preceded by three digits and  any
+        is  another pattern that matches "foo" preceded by three digits and any
         three characters that are not "999".
  CONDITIONAL SUBPATTERNS
-        It  is possible to cause the matching process to obey a subpattern con-
+        It is possible to cause the matching process to obey a subpattern  con-
-        ditionally or to choose between two alternative subpatterns,  depending
+        ditionally  or to choose between two alternative subpatterns, depending
-        on  the result of an assertion, or whether a specific capturing subpat-
+        on the result of an assertion, or whether a specific capturing  subpat-
-        tern has already been matched. The two possible  forms  of  conditional
+        tern  has  already  been matched. The two possible forms of conditional
         subpattern are:
           (?(condition)yes-pattern)
           (?(condition)yes-pattern|no-pattern)
-        If  the  condition is satisfied, the yes-pattern is used; otherwise the
+        If the condition is satisfied, the yes-pattern is used;  otherwise  the
-        no-pattern (if present) is used. If there are more  than  two  alterna-
+        no-pattern  (if  present)  is used. If there are more than two alterna-
-        tives  in  the subpattern, a compile-time error occurs. Each of the two
+        tives in the subpattern, a compile-time error occurs. Each of  the  two
         alternatives may itself contain nested subpatterns of any form, includ-
         ing  conditional  subpatterns;  the  restriction  to  two  alternatives
         applies only at the level of the condition. This pattern fragment is an
-Line 5134 
 CONDITIONAL SUBPATTERNS
+Line 5152 
 CONDITIONAL SUBPATTERNS
           (?(1) (A|B|C) | (D | (?(2)E|F) | E) )
-        There  are  four  kinds of condition: references to subpatterns, refer-
+        There are four kinds of condition: references  to  subpatterns,  refer-
         ences to recursion, a pseudo-condition called DEFINE, and assertions.
     Checking for a used subpattern by number
-        If the text between the parentheses consists of a sequence  of  digits,
+        If  the  text between the parentheses consists of a sequence of digits,
         the condition is true if a capturing subpattern of that number has pre-
-        viously matched. If there is more than one  capturing  subpattern  with
+        viously  matched.  If  there is more than one capturing subpattern with
-        the  same  number  (see  the earlier section about duplicate subpattern
+        the same number (see the earlier  section  about  duplicate  subpattern
-        numbers), the condition is true if any of them have matched. An  alter-
+        numbers),  the condition is true if any of them have matched. An alter-
-        native  notation is to precede the digits with a plus or minus sign. In
+        native notation is to precede the digits with a plus or minus sign.  In
-        this case, the subpattern number is relative rather than absolute.  The
+        this  case, the subpattern number is relative rather than absolute. The
-        most  recently opened parentheses can be referenced by (?(-1), the next
+        most recently opened parentheses can be referenced by (?(-1), the  next
-        most recent by (?(-2), and so on. Inside loops it can also  make  sense
+        most  recent  by (?(-2), and so on. Inside loops it can also make sense
         to refer to subsequent groups. The next parentheses to be opened can be
-        referenced as (?(+1), and so on. (The value zero in any of these  forms
+        referenced  as (?(+1), and so on. (The value zero in any of these forms
         is not used; it provokes a compile-time error.)
-        Consider  the  following  pattern, which contains non-significant white
+        Consider the following pattern, which  contains  non-significant  white
         space to make it more readable (assume the PCRE_EXTENDED option) and to
         divide it into three parts for ease of discussion:
           ( \( )?    [^()]+    (?(1) \) )
-        The  first  part  matches  an optional opening parenthesis, and if that
+        The first part matches an optional opening  parenthesis,  and  if  that
         character is present, sets it as the first captured substring. The sec-
-        ond  part  matches one or more characters that are not parentheses. The
+        ond part matches one or more characters that are not  parentheses.  The
-        third part is a conditional subpattern that tests whether  or  not  the
+        third  part  is  a conditional subpattern that tests whether or not the
-        first  set  of  parentheses  matched.  If they did, that is, if subject
+        first set of parentheses matched. If they  did,  that  is,  if  subject
-        started with an opening parenthesis, the condition is true, and so  the
+        started  with an opening parenthesis, the condition is true, and so the
-        yes-pattern  is  executed and a closing parenthesis is required. Other-
+        yes-pattern is executed and a closing parenthesis is  required.  Other-
-        wise, since no-pattern is not present, the subpattern matches  nothing.
+        wise,  since no-pattern is not present, the subpattern matches nothing.
-        In  other  words,  this  pattern matches a sequence of non-parentheses,
+        In other words, this pattern matches  a  sequence  of  non-parentheses,
         optionally enclosed in parentheses.
-        If you were embedding this pattern in a larger one,  you  could  use  a
+        If  you  were  embedding  this pattern in a larger one, you could use a
         relative reference:
           ...other stuff... ( \( )?    [^()]+    (?(-1) \) ) ...
-        This  makes  the  fragment independent of the parentheses in the larger
+        This makes the fragment independent of the parentheses  in  the  larger
         pattern.
     Checking for a used subpattern by name
-        Perl uses the syntax (?(<name>)...) or (?('name')...)  to  test  for  a
+        Perl  uses  the  syntax  (?(<name>)...) or (?('name')...) to test for a
-        used  subpattern  by  name.  For compatibility with earlier versions of
+        used subpattern by name. For compatibility  with  earlier  versions  of
-        PCRE, which had this facility before Perl, the syntax  (?(name)...)  is
+        PCRE,  which  had this facility before Perl, the syntax (?(name)...) is
-        also  recognized. However, there is a possible ambiguity with this syn-
+        also recognized. However, there is a possible ambiguity with this  syn-
-        tax, because subpattern names may  consist  entirely  of  digits.  PCRE
+        tax,  because  subpattern  names  may  consist entirely of digits. PCRE
-        looks  first for a named subpattern; if it cannot find one and the name
+        looks first for a named subpattern; if it cannot find one and the  name
-        consists entirely of digits, PCRE looks for a subpattern of  that  num-
+        consists  entirely  of digits, PCRE looks for a subpattern of that num-
-        ber,  which must be greater than zero. Using subpattern names that con-
+        ber, which must be greater than zero. Using subpattern names that  con-
         sist entirely of digits is not recommended.
         Rewriting the above example to use a named subpattern gives this:
           (?<OPEN> \( )?    [^()]+    (?(<OPEN>) \) )
-        If the name used in a condition of this kind is a duplicate,  the  test
+        If  the  name used in a condition of this kind is a duplicate, the test
-        is  applied to all subpatterns of the same name, and is true if any one
+        is applied to all subpatterns of the same name, and is true if any  one
         of them has matched.
     Checking for pattern recursion
         If the condition is the string (R), and there is no subpattern with the
-        name  R, the condition is true if a recursive call to the whole pattern
+        name R, the condition is true if a recursive call to the whole  pattern
         or any subpattern has been made. If digits or a name preceded by amper-
         sand follow the letter R, for example:
-Line 5208 
 CONDITIONAL SUBPATTERNS
+Line 5226 
 CONDITIONAL SUBPATTERNS
         the condition is true if the most recent recursion is into a subpattern
         whose number or name is given. This condition does not check the entire
-        recursion  stack.  If  the  name  used in a condition of this kind is a
+        recursion stack. If the name used in a condition  of  this  kind  is  a
         duplicate, the test is applied to all subpatterns of the same name, and
         is true if any one of them is the most recent recursion.
-        At  "top  level",  all  these recursion test conditions are false.  The
+        At "top level", all these recursion test  conditions  are  false.   The
         syntax for recursive patterns is described below.
     Defining subpatterns for use by reference only
-        If the condition is the string (DEFINE), and  there  is  no  subpattern
+        If  the  condition  is  the string (DEFINE), and there is no subpattern
-        with  the  name  DEFINE,  the  condition is always false. In this case,
+        with the name DEFINE, the condition is  always  false.  In  this  case,
-        there may be only one alternative  in  the  subpattern.  It  is  always
+        there  may  be  only  one  alternative  in the subpattern. It is always
-        skipped  if  control  reaches  this  point  in the pattern; the idea of
+        skipped if control reaches this point  in  the  pattern;  the  idea  of
-        DEFINE is that it can be used to define "subroutines" that can be  ref-
+        DEFINE  is that it can be used to define subroutines that can be refer-
-        erenced  from elsewhere. (The use of "subroutines" is described below.)
+        enced from elsewhere. (The use of subroutines is described below.)  For
-        For  example,  a  pattern  to   match   an   IPv4   address   such   as
+        example,  a  pattern  to match an IPv4 address such as "192.168.23.245"
-        "192.168.23.245" could be written like this (ignore whitespace and line
+        could be written like this (ignore whitespace and line breaks):
-        breaks):
           (?(DEFINE) (?<byte> 2[0-4]\d | 25[0-5] | 1\d\d | [1-9]?\d) )
           \b (?&byte) (\.(?&byte)){3} \b
-Line 5312 
 RECURSIVE PATTERNS
+Line 5329 
 RECURSIVE PATTERNS
         into Perl at release 5.10.
         A special item that consists of (? followed by a  number  greater  than
-        zero and a closing parenthesis is a recursive call of the subpattern of
+        zero  and  a  closing parenthesis is a recursive subroutine call of the
-        the given number, provided that it occurs inside that  subpattern.  (If
+        subpattern of the given number, provided that  it  occurs  inside  that
-        not,  it  is  a  "subroutine" call, which is described in the next sec-
+        subpattern.  (If  not,  it is a non-recursive subroutine call, which is
-        tion.) The special item (?R) or (?0) is a recursive call of the  entire
+        described in the next section.) The special item  (?R)  or  (?0)  is  a
-        regular expression.
+        recursive call of the entire regular expression.
         This  PCRE  pattern  solves  the nested parentheses problem (assume the
         PCRE_EXTENDED option is set so that white space is ignored):
-Line 5348 
 RECURSIVE PATTERNS
+Line 5365 
 RECURSIVE PATTERNS
         It is also possible to refer to  subsequently  opened  parentheses,  by
         writing  references  such  as (?+2). However, these cannot be recursive
         because the reference is not inside the  parentheses  that  are  refer-
-        enced.  They  are  always  "subroutine" calls, as described in the next
+        enced.  They are always non-recursive subroutine calls, as described in
-        section.
+        the next section.
         An alternative approach is to use named parentheses instead.  The  Perl
         syntax  for  this  is (?&name); PCRE's earlier syntax (?P>name) is also
-Line 5382 
 RECURSIVE PATTERNS
+Line 5399<