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Revision 146 - (hide annotations) (download)
Thu Apr 5 09:17:28 2007 UTC (8 years ago) by ph10
File size: 13521 byte(s)
Another buglet in pcretest for "any" newline and /g.

1 nigel 41 News about PCRE releases
2     ------------------------
4 ph10 122
5 ph10 128 Release 7.1 20-Mar-07
6 nigel 93 ---------------------
8 ph10 122 There are no new features in this release. A few bugs are fixed (see ChangeLog
9     for details), but the major change is a complete re-implementation of the build
10 ph10 123 system. This now has full Autotools support and so is now "standard" in some
11 ph10 122 sense. It should help with compiling PCRE in a wide variety of environments.
13 ph10 146 NOTE: when building shared libraries for Windows, three dlls are now built,
14     called libpcre, libpcreposix, and libpcrecpp. Previously, everything was
15     included in a single dll.
17     Another important change is that the dftables auxiliary program is no longer
18 ph10 128 compiled and run at "make" time by default. Instead, a default set of character
19     tables (assuming ASCII coding) is used. If you want to use dftables to generate
20     the character tables as previously, add --enable-rebuild-chartables to the
21     "configure" command. You must do this if you are compiling PCRE to run on a
22     system that uses EBCDIC code.
23 ph10 122
24 ph10 128 There is a discussion about character tables in the README file. The default is
25     not to use dftables so that that there is no problem when cross-compiling.
28 ph10 122 Release 7.0 19-Dec-06
29     ---------------------
31 nigel 93 This release has a new major number because there have been some internal
32     upheavals to facilitate the addition of new optimizations and other facilities,
33     and to make subsequent maintenance and extension easier. Compilation is likely
34     to be a bit slower, but there should be no major effect on runtime performance.
35     Previously compiled patterns are NOT upwards compatible with this release. If
36     you have saved compiled patterns from a previous release, you will have to
37     re-compile them. Important changes that are visible to users are:
39     1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
40     some more scripts.
42     2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
43     sequence as a newline.
45     3. The \R escape matches a single Unicode newline sequence as a single unit.
47     4. New features that will appear in Perl 5.10 are now in PCRE. These include
48     alternative Perl syntax for named parentheses, and Perl syntax for
49     recursion.
51     5. The C++ wrapper interface has been extended by the addition of a
52     QuoteMeta function and the ability to allow copy construction and
53     assignment.
55     For a complete list of changes, see the ChangeLog file.
58 nigel 91 Release 6.7 04-Jul-06
59     ---------------------
61     The main additions to this release are the ability to use the same name for
62     multiple sets of parentheses, and support for CRLF line endings in both the
63     library and pcregrep (and in pcretest for testing).
65     Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
66     significantly reduced for certain subject strings.
69 nigel 87 Release 6.5 01-Feb-06
70     ---------------------
72     Important changes in this release:
74     1. A number of new features have been added to pcregrep.
76     2. The Unicode property tables have been updated to Unicode 4.1.0, and the
77     supported properties have been extended with script names such as "Arabic",
78     and the derived properties "Any" and "L&". This has necessitated a change to
79     the interal format of compiled patterns. Any saved compiled patterns that
80     use \p or \P must be recompiled.
82     3. The specification of recursion in patterns has been changed so that all
83     recursive subpatterns are automatically treated as atomic groups. Thus, for
84     example, (?R) is treated as if it were (?>(?R)). This is necessary because
85     otherwise there are situations where recursion does not work.
87     See the ChangeLog for a complete list of changes, which include a number of bug
88     fixes and tidies.
91 nigel 77 Release 6.0 07-Jun-05
92     ---------------------
94     The release number has been increased to 6.0 because of the addition of several
95     major new pieces of functionality.
97     A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
98     algorithm, has been added. This has a number of advantages for certain cases,
99     though it does run more slowly, and lacks the ability to capture substrings. On
100     the other hand, it does find all matches, not just the first, and it works
101     better for partial matching. The pcrematching man page discusses the
102     differences.
104     The pcretest program has been enhanced so that it can make use of the new
105     pcre_dfa_exec() matching function and the extra features it provides.
107     The distribution now includes a C++ wrapper library. This is built
108     automatically if a C++ compiler is found. The pcrecpp man page discusses this
109     interface.
111     The code itself has been re-organized into many more files, one for each
112     function, so it no longer requires everything to be linked in when static
113     linkage is used. As a consequence, some internal functions have had to have
114     their names exposed. These functions all have names starting with _pcre_. They
115     are undocumented, and are not intended for use by outside callers.
117     The pcregrep program has been enhanced with new functionality such as
118     multiline-matching and options for output more matching context. See the
119     ChangeLog for a complete list of changes to the library and the utility
120     programs.
123 nigel 75 Release 5.0 13-Sep-04
124     ---------------------
126     The licence under which PCRE is released has been changed to the more
127     conventional "BSD" licence.
129     In the code, some bugs have been fixed, and there are also some major changes
130     in this release (which is why I've increased the number to 5.0). Some changes
131     are internal rearrangements, and some provide a number of new facilities. The
132     new features are:
134     1. There's an "automatic callout" feature that inserts callouts before every
135     item in the regex, and there's a new callout field that gives the position
136     in the pattern - useful for debugging and tracing.
138     2. The extra_data structure can now be used to pass in a set of character
139     tables at exec time. This is useful if compiled regex are saved and re-used
140     at a later time when the tables may not be at the same address. If the
141     default internal tables are used, the pointer saved with the compiled
142     pattern is now set to NULL, which means that you don't need to do anything
143     special unless you are using custom tables.
145     3. It is possible, with some restrictions on the content of the regex, to
146     request "partial" matching. A special return code is given if all of the
147     subject string matched part of the regex. This could be useful for testing
148     an input field as it is being typed.
150     4. There is now some optional support for Unicode character properties, which
151     means that the patterns items such as \p{Lu} and \X can now be used. Only
152     the general category properties are supported. If PCRE is compiled with this
153     support, an additional 90K data structure is include, which increases the
154     size of the library dramatically.
156     5. There is support for saving compiled patterns and re-using them later.
158     6. There is support for running regular expressions that were compiled on a
159     different host with the opposite endianness.
161     7. The pcretest program has been extended to accommodate the new features.
163     The main internal rearrangement is that sequences of literal characters are no
164     longer handled as strings. Instead, each character is handled on its own. This
165     makes some UTF-8 handling easier, and makes the support of partial matching
166     possible. Compiled patterns containing long literal strings will be larger as a
167     result of this change; I hope that performance will not be much affected.
170 nigel 73 Release 4.5 01-Dec-03
171     ---------------------
173     Again mainly a bug-fix and tidying release, with only a couple of new features:
175     1. It's possible now to compile PCRE so that it does not use recursive
176     function calls when matching. Instead it gets memory from the heap. This slows
177     things down, but may be necessary on systems with limited stacks.
179     2. UTF-8 string checking has been tightened to reject overlong sequences and to
180     check that a starting offset points to the start of a character. Failure of the
181     latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
183     3. PCRE can now be compiled for systems that use EBCDIC code.
186 nigel 71 Release 4.4 21-Aug-03
187     ---------------------
189     This is mainly a bug-fix and tidying release. The only new feature is that PCRE
190     checks UTF-8 strings for validity by default. There is an option to suppress
191     this, just in case anybody wants that teeny extra bit of performance.
194     Releases 4.1 - 4.3
195     ------------------
197     Sorry, I forgot about updating the NEWS file for these releases. Please take a
198     look at ChangeLog.
201 nigel 63 Release 4.0 17-Feb-03
202     ---------------------
204     There have been a lot of changes for the 4.0 release, adding additional
205     functionality and mending bugs. Below is a list of the highlights of the new
206     functionality. For full details of these features, please consult the
207     documentation. For a complete list of changes, see the ChangeLog file.
209     1. Support for Perl's \Q...\E escapes.
211     2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
212     package. They provide some syntactic sugar for simple cases of "atomic
213     grouping".
215     3. Support for the \G assertion. It is true when the current matching position
216     is at the start point of the match.
218     4. A new feature that provides some of the functionality that Perl provides
219     with (?{...}). The facility is termed a "callout". The way it is done in PCRE
220     is for the caller to provide an optional function, by setting pcre_callout to
221     its entry point. To get the function called, the regex must include (?C) at
222     appropriate points.
224     5. Support for recursive calls to individual subpatterns. This makes it really
225     easy to get totally confused.
227     6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
228     name a group.
230     7. Several extensions to UTF-8 support; it is now fairly complete. There is an
231     option for pcregrep to make it operate in UTF-8 mode.
233     8. The single man page has been split into a number of separate man pages.
234     These also give rise to individual HTML pages which are put in a separate
235     directory. There is an index.html page that lists them all. Some hyperlinking
236     between the pages has been installed.
239 nigel 53 Release 3.5 15-Aug-01
240     ---------------------
242     1. The configuring system has been upgraded to use later versions of autoconf
243     and libtool. By default it builds both a shared and a static library if the OS
244     supports it. You can use --disable-shared or --disable-static on the configure
245     command if you want only one of them.
247     2. The pcretest utility is now installed along with pcregrep because it is
248     useful for users (to test regexs) and by doing this, it automatically gets
249     relinked by libtool. The documentation has been turned into a man page, so
250     there are now .1, .txt, and .html versions in /doc.
252     3. Upgrades to pcregrep:
253     (i) Added long-form option names like gnu grep.
254     (ii) Added --help to list all options with an explanatory phrase.
255     (iii) Added -r, --recursive to recurse into sub-directories.
256     (iv) Added -f, --file to read patterns from a file.
258     4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
259     script, to force use of CR or LF instead of \n in the source. On non-Unix
260     systems, the value can be set in config.h.
262     5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
263     absolute limit. Changed the text of the error message to make this clear, and
264     likewise updated the man page.
266     6. The limit of 99 on the number of capturing subpatterns has been removed.
267     The new limit is 65535, which I hope will not be a "real" limit.
270 nigel 49 Release 3.3 01-Aug-00
271     ---------------------
273     There is some support for UTF-8 character strings. This is incomplete and
274     experimental. The documentation describes what is and what is not implemented.
275     Otherwise, this is just a bug-fixing release.
278 nigel 43 Release 3.0 01-Feb-00
279     ---------------------
280 nigel 41
281 nigel 43 1. A "configure" script is now used to configure PCRE for Unix systems. It
282     builds a Makefile, a config.h file, and the pcre-config script.
284     2. PCRE is built as a shared library by default.
286     3. There is support for POSIX classes such as [:alpha:].
288     5. There is an experimental recursion feature.
290 nigel 41 ----------------------------------------------------------------------------
293     Please note that there has been a change in the API such that a larger
294     ovector is required at matching time, to provide some additional workspace.
295     The new man page has details. This change was necessary in order to support
296     some of the new functionality in Perl 5.005.
300     Another (I hope this is the last!) change has been made to the API for the
301     pcre_compile() function. An additional argument has been added to make it
302     possible to pass over a pointer to character tables built in the current
303     locale by pcre_maketables(). To use the default tables, this new arguement
304     should be passed as NULL.
308     Yet another (and again I hope this really is the last) change has been made
309     to the API for the pcre_exec() function. An additional argument has been
310     added to make it possible to start the match other than at the start of the
311     subject string. This is important if there are lookbehinds. The new man
312     page has the details, but you just want to convert existing programs, all
313     you need to do is to stick in a new fifth argument to pcre_exec(), with a
314     value of zero. For example, change
316     pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
317     to
318     pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)
320     ****


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