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Revision 184 - (hide annotations) (download)
Tue Jun 19 13:26:46 2007 UTC (7 years, 2 months ago) by ph10
Original Path: code/trunk/NEWS
File size: 14998 byte(s)
Fix non-UTF-8 mode Unicode properties bug; prepare for 7.2 release.

1 nigel 41 News about PCRE releases
2     ------------------------
3    
4 ph10 122
5 ph10 184 Release 7.2 19-Jun-07
6 ph10 157 ---------------------
7    
8 ph10 172 WARNING: saved patterns that were compiled by earlier versions of PCRE must be
9 ph10 181 recompiled for use with 7.2 (necessitated by the addition of \K, \h, \H, \v,
10     and \V).
11 ph10 168
12 ph10 159 Correction to the notes for 7.1: the note about shared libraries for Windows is
13     wrong. Previously, three libraries were built, but each could function
14     independently. For example, the pcreposix library also included all the
15     functions from the basic pcre library. The change is that the three libraries
16     are no longer independent. They are like the Unix libraries. To use the
17     pcreposix functions, for example, you need to link with both the pcreposix and
18 ph10 157 the basic pcre library.
19    
20 ph10 166 Some more features from Perl 5.10 have been added:
21 ph10 157
22 ph10 166 (?-n) and (?+n) relative references for recursion and subroutines.
23 ph10 172
24     (?(-n) and (?(+n) relative references as conditions.
25 ph10 182
26 ph10 181 \k{name} and \g{name} are synonyms for \k<name>.
27 ph10 172
28 ph10 168 \K to reset the start of the matched string; for example, (foo)\Kbar
29 ph10 175 matches bar preceded by foo, but only sets bar as the matched string.
30 ph10 182
31     (?| introduces a group where the capturing parentheses in each alternative
32     start from the same number; for example, (?|(abc)|(xyz)) sets capturing
33 ph10 175 parentheses number 1 in both cases.
34 ph10 166
35 ph10 182 \h, \H, \v, \V match horizontal and vertical whitespace, respectively.
36 ph10 166
37 ph10 182
38 ph10 155 Release 7.1 24-Apr-07
39 nigel 93 ---------------------
40    
41 ph10 155 There is only one new feature in this release: a linebreak setting of
42     PCRE_NEWLINE_ANYCRLF. It is a cut-down version of PCRE_NEWLINE_ANY, which
43     recognizes only CRLF, CR, and LF as linebreaks.
44 ph10 122
45 ph10 155 A few bugs are fixed (see ChangeLog for details), but the major change is a
46     complete re-implementation of the build system. This now has full Autotools
47     support and so is now "standard" in some sense. It should help with compiling
48     PCRE in a wide variety of environments.
49    
50 ph10 146 NOTE: when building shared libraries for Windows, three dlls are now built,
51     called libpcre, libpcreposix, and libpcrecpp. Previously, everything was
52     included in a single dll.
53    
54     Another important change is that the dftables auxiliary program is no longer
55 ph10 128 compiled and run at "make" time by default. Instead, a default set of character
56     tables (assuming ASCII coding) is used. If you want to use dftables to generate
57     the character tables as previously, add --enable-rebuild-chartables to the
58     "configure" command. You must do this if you are compiling PCRE to run on a
59     system that uses EBCDIC code.
60 ph10 122
61 ph10 128 There is a discussion about character tables in the README file. The default is
62     not to use dftables so that that there is no problem when cross-compiling.
63    
64    
65 ph10 122 Release 7.0 19-Dec-06
66     ---------------------
67    
68 nigel 93 This release has a new major number because there have been some internal
69     upheavals to facilitate the addition of new optimizations and other facilities,
70     and to make subsequent maintenance and extension easier. Compilation is likely
71     to be a bit slower, but there should be no major effect on runtime performance.
72     Previously compiled patterns are NOT upwards compatible with this release. If
73     you have saved compiled patterns from a previous release, you will have to
74     re-compile them. Important changes that are visible to users are:
75    
76     1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
77     some more scripts.
78    
79     2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
80     sequence as a newline.
81    
82     3. The \R escape matches a single Unicode newline sequence as a single unit.
83    
84     4. New features that will appear in Perl 5.10 are now in PCRE. These include
85     alternative Perl syntax for named parentheses, and Perl syntax for
86     recursion.
87    
88     5. The C++ wrapper interface has been extended by the addition of a
89     QuoteMeta function and the ability to allow copy construction and
90     assignment.
91    
92     For a complete list of changes, see the ChangeLog file.
93    
94    
95 nigel 91 Release 6.7 04-Jul-06
96     ---------------------
97    
98     The main additions to this release are the ability to use the same name for
99     multiple sets of parentheses, and support for CRLF line endings in both the
100     library and pcregrep (and in pcretest for testing).
101    
102     Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
103     significantly reduced for certain subject strings.
104    
105    
106 nigel 87 Release 6.5 01-Feb-06
107     ---------------------
108    
109     Important changes in this release:
110    
111     1. A number of new features have been added to pcregrep.
112    
113     2. The Unicode property tables have been updated to Unicode 4.1.0, and the
114     supported properties have been extended with script names such as "Arabic",
115     and the derived properties "Any" and "L&". This has necessitated a change to
116     the interal format of compiled patterns. Any saved compiled patterns that
117     use \p or \P must be recompiled.
118    
119     3. The specification of recursion in patterns has been changed so that all
120     recursive subpatterns are automatically treated as atomic groups. Thus, for
121     example, (?R) is treated as if it were (?>(?R)). This is necessary because
122     otherwise there are situations where recursion does not work.
123    
124     See the ChangeLog for a complete list of changes, which include a number of bug
125     fixes and tidies.
126    
127    
128 nigel 77 Release 6.0 07-Jun-05
129     ---------------------
130    
131     The release number has been increased to 6.0 because of the addition of several
132     major new pieces of functionality.
133    
134     A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
135     algorithm, has been added. This has a number of advantages for certain cases,
136     though it does run more slowly, and lacks the ability to capture substrings. On
137     the other hand, it does find all matches, not just the first, and it works
138     better for partial matching. The pcrematching man page discusses the
139     differences.
140    
141     The pcretest program has been enhanced so that it can make use of the new
142     pcre_dfa_exec() matching function and the extra features it provides.
143    
144     The distribution now includes a C++ wrapper library. This is built
145     automatically if a C++ compiler is found. The pcrecpp man page discusses this
146     interface.
147    
148     The code itself has been re-organized into many more files, one for each
149     function, so it no longer requires everything to be linked in when static
150     linkage is used. As a consequence, some internal functions have had to have
151     their names exposed. These functions all have names starting with _pcre_. They
152     are undocumented, and are not intended for use by outside callers.
153    
154     The pcregrep program has been enhanced with new functionality such as
155     multiline-matching and options for output more matching context. See the
156     ChangeLog for a complete list of changes to the library and the utility
157     programs.
158    
159    
160 nigel 75 Release 5.0 13-Sep-04
161     ---------------------
162    
163     The licence under which PCRE is released has been changed to the more
164     conventional "BSD" licence.
165    
166     In the code, some bugs have been fixed, and there are also some major changes
167     in this release (which is why I've increased the number to 5.0). Some changes
168     are internal rearrangements, and some provide a number of new facilities. The
169     new features are:
170    
171     1. There's an "automatic callout" feature that inserts callouts before every
172     item in the regex, and there's a new callout field that gives the position
173     in the pattern - useful for debugging and tracing.
174    
175     2. The extra_data structure can now be used to pass in a set of character
176     tables at exec time. This is useful if compiled regex are saved and re-used
177     at a later time when the tables may not be at the same address. If the
178     default internal tables are used, the pointer saved with the compiled
179     pattern is now set to NULL, which means that you don't need to do anything
180     special unless you are using custom tables.
181    
182     3. It is possible, with some restrictions on the content of the regex, to
183     request "partial" matching. A special return code is given if all of the
184     subject string matched part of the regex. This could be useful for testing
185     an input field as it is being typed.
186    
187     4. There is now some optional support for Unicode character properties, which
188     means that the patterns items such as \p{Lu} and \X can now be used. Only
189     the general category properties are supported. If PCRE is compiled with this
190     support, an additional 90K data structure is include, which increases the
191     size of the library dramatically.
192    
193     5. There is support for saving compiled patterns and re-using them later.
194    
195     6. There is support for running regular expressions that were compiled on a
196     different host with the opposite endianness.
197    
198     7. The pcretest program has been extended to accommodate the new features.
199    
200     The main internal rearrangement is that sequences of literal characters are no
201     longer handled as strings. Instead, each character is handled on its own. This
202     makes some UTF-8 handling easier, and makes the support of partial matching
203     possible. Compiled patterns containing long literal strings will be larger as a
204     result of this change; I hope that performance will not be much affected.
205    
206    
207 nigel 73 Release 4.5 01-Dec-03
208     ---------------------
209    
210     Again mainly a bug-fix and tidying release, with only a couple of new features:
211    
212     1. It's possible now to compile PCRE so that it does not use recursive
213     function calls when matching. Instead it gets memory from the heap. This slows
214     things down, but may be necessary on systems with limited stacks.
215    
216     2. UTF-8 string checking has been tightened to reject overlong sequences and to
217     check that a starting offset points to the start of a character. Failure of the
218     latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
219    
220     3. PCRE can now be compiled for systems that use EBCDIC code.
221    
222    
223 nigel 71 Release 4.4 21-Aug-03
224     ---------------------
225    
226     This is mainly a bug-fix and tidying release. The only new feature is that PCRE
227     checks UTF-8 strings for validity by default. There is an option to suppress
228     this, just in case anybody wants that teeny extra bit of performance.
229    
230    
231     Releases 4.1 - 4.3
232     ------------------
233    
234     Sorry, I forgot about updating the NEWS file for these releases. Please take a
235     look at ChangeLog.
236    
237    
238 nigel 63 Release 4.0 17-Feb-03
239     ---------------------
240    
241     There have been a lot of changes for the 4.0 release, adding additional
242     functionality and mending bugs. Below is a list of the highlights of the new
243     functionality. For full details of these features, please consult the
244     documentation. For a complete list of changes, see the ChangeLog file.
245    
246     1. Support for Perl's \Q...\E escapes.
247    
248     2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
249     package. They provide some syntactic sugar for simple cases of "atomic
250     grouping".
251    
252     3. Support for the \G assertion. It is true when the current matching position
253     is at the start point of the match.
254    
255     4. A new feature that provides some of the functionality that Perl provides
256     with (?{...}). The facility is termed a "callout". The way it is done in PCRE
257     is for the caller to provide an optional function, by setting pcre_callout to
258     its entry point. To get the function called, the regex must include (?C) at
259     appropriate points.
260    
261     5. Support for recursive calls to individual subpatterns. This makes it really
262     easy to get totally confused.
263    
264     6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
265     name a group.
266    
267     7. Several extensions to UTF-8 support; it is now fairly complete. There is an
268     option for pcregrep to make it operate in UTF-8 mode.
269    
270     8. The single man page has been split into a number of separate man pages.
271     These also give rise to individual HTML pages which are put in a separate
272     directory. There is an index.html page that lists them all. Some hyperlinking
273     between the pages has been installed.
274    
275    
276 nigel 53 Release 3.5 15-Aug-01
277     ---------------------
278    
279     1. The configuring system has been upgraded to use later versions of autoconf
280     and libtool. By default it builds both a shared and a static library if the OS
281     supports it. You can use --disable-shared or --disable-static on the configure
282     command if you want only one of them.
283    
284     2. The pcretest utility is now installed along with pcregrep because it is
285     useful for users (to test regexs) and by doing this, it automatically gets
286     relinked by libtool. The documentation has been turned into a man page, so
287     there are now .1, .txt, and .html versions in /doc.
288    
289     3. Upgrades to pcregrep:
290     (i) Added long-form option names like gnu grep.
291     (ii) Added --help to list all options with an explanatory phrase.
292     (iii) Added -r, --recursive to recurse into sub-directories.
293     (iv) Added -f, --file to read patterns from a file.
294    
295     4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
296     script, to force use of CR or LF instead of \n in the source. On non-Unix
297     systems, the value can be set in config.h.
298    
299     5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
300     absolute limit. Changed the text of the error message to make this clear, and
301     likewise updated the man page.
302    
303     6. The limit of 99 on the number of capturing subpatterns has been removed.
304     The new limit is 65535, which I hope will not be a "real" limit.
305    
306    
307 nigel 49 Release 3.3 01-Aug-00
308     ---------------------
309    
310     There is some support for UTF-8 character strings. This is incomplete and
311     experimental. The documentation describes what is and what is not implemented.
312     Otherwise, this is just a bug-fixing release.
313    
314    
315 nigel 43 Release 3.0 01-Feb-00
316     ---------------------
317 nigel 41
318 nigel 43 1. A "configure" script is now used to configure PCRE for Unix systems. It
319     builds a Makefile, a config.h file, and the pcre-config script.
320    
321     2. PCRE is built as a shared library by default.
322    
323     3. There is support for POSIX classes such as [:alpha:].
324    
325     5. There is an experimental recursion feature.
326    
327 nigel 41 ----------------------------------------------------------------------------
328     IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00
329    
330     Please note that there has been a change in the API such that a larger
331     ovector is required at matching time, to provide some additional workspace.
332     The new man page has details. This change was necessary in order to support
333     some of the new functionality in Perl 5.005.
334    
335     IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.00
336    
337     Another (I hope this is the last!) change has been made to the API for the
338     pcre_compile() function. An additional argument has been added to make it
339     possible to pass over a pointer to character tables built in the current
340     locale by pcre_maketables(). To use the default tables, this new arguement
341     should be passed as NULL.
342    
343     IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.05
344    
345     Yet another (and again I hope this really is the last) change has been made
346     to the API for the pcre_exec() function. An additional argument has been
347     added to make it possible to start the match other than at the start of the
348     subject string. This is important if there are lookbehinds. The new man
349     page has the details, but you just want to convert existing programs, all
350     you need to do is to stick in a new fifth argument to pcre_exec(), with a
351     value of zero. For example, change
352    
353     pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
354     to
355     pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)
356    
357     ****

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