ViewVC logotype

Contents of /code/trunk/NEWS

Parent Directory Parent Directory | Revision Log Revision Log

Revision 159 - (show annotations)
Wed May 2 10:27:18 2007 UTC (14 years, 5 months ago) by ph10
File size: 14194 byte(s)
Add code to configure.ac to remove -g from default CFLAGS and CXXFLAGS.
1 News about PCRE releases
2 ------------------------
5 Release 7.2 30-Apr-07
6 ---------------------
8 Correction to the notes for 7.1: the note about shared libraries for Windows is
9 wrong. Previously, three libraries were built, but each could function
10 independently. For example, the pcreposix library also included all the
11 functions from the basic pcre library. The change is that the three libraries
12 are no longer independent. They are like the Unix libraries. To use the
13 pcreposix functions, for example, you need to link with both the pcreposix and
14 the basic pcre library.
17 Release 7.1 24-Apr-07
18 ---------------------
20 There is only one new feature in this release: a linebreak setting of
21 PCRE_NEWLINE_ANYCRLF. It is a cut-down version of PCRE_NEWLINE_ANY, which
22 recognizes only CRLF, CR, and LF as linebreaks.
24 A few bugs are fixed (see ChangeLog for details), but the major change is a
25 complete re-implementation of the build system. This now has full Autotools
26 support and so is now "standard" in some sense. It should help with compiling
27 PCRE in a wide variety of environments.
29 NOTE: when building shared libraries for Windows, three dlls are now built,
30 called libpcre, libpcreposix, and libpcrecpp. Previously, everything was
31 included in a single dll.
33 Another important change is that the dftables auxiliary program is no longer
34 compiled and run at "make" time by default. Instead, a default set of character
35 tables (assuming ASCII coding) is used. If you want to use dftables to generate
36 the character tables as previously, add --enable-rebuild-chartables to the
37 "configure" command. You must do this if you are compiling PCRE to run on a
38 system that uses EBCDIC code.
40 There is a discussion about character tables in the README file. The default is
41 not to use dftables so that that there is no problem when cross-compiling.
44 Release 7.0 19-Dec-06
45 ---------------------
47 This release has a new major number because there have been some internal
48 upheavals to facilitate the addition of new optimizations and other facilities,
49 and to make subsequent maintenance and extension easier. Compilation is likely
50 to be a bit slower, but there should be no major effect on runtime performance.
51 Previously compiled patterns are NOT upwards compatible with this release. If
52 you have saved compiled patterns from a previous release, you will have to
53 re-compile them. Important changes that are visible to users are:
55 1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
56 some more scripts.
58 2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
59 sequence as a newline.
61 3. The \R escape matches a single Unicode newline sequence as a single unit.
63 4. New features that will appear in Perl 5.10 are now in PCRE. These include
64 alternative Perl syntax for named parentheses, and Perl syntax for
65 recursion.
67 5. The C++ wrapper interface has been extended by the addition of a
68 QuoteMeta function and the ability to allow copy construction and
69 assignment.
71 For a complete list of changes, see the ChangeLog file.
74 Release 6.7 04-Jul-06
75 ---------------------
77 The main additions to this release are the ability to use the same name for
78 multiple sets of parentheses, and support for CRLF line endings in both the
79 library and pcregrep (and in pcretest for testing).
81 Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
82 significantly reduced for certain subject strings.
85 Release 6.5 01-Feb-06
86 ---------------------
88 Important changes in this release:
90 1. A number of new features have been added to pcregrep.
92 2. The Unicode property tables have been updated to Unicode 4.1.0, and the
93 supported properties have been extended with script names such as "Arabic",
94 and the derived properties "Any" and "L&". This has necessitated a change to
95 the interal format of compiled patterns. Any saved compiled patterns that
96 use \p or \P must be recompiled.
98 3. The specification of recursion in patterns has been changed so that all
99 recursive subpatterns are automatically treated as atomic groups. Thus, for
100 example, (?R) is treated as if it were (?>(?R)). This is necessary because
101 otherwise there are situations where recursion does not work.
103 See the ChangeLog for a complete list of changes, which include a number of bug
104 fixes and tidies.
107 Release 6.0 07-Jun-05
108 ---------------------
110 The release number has been increased to 6.0 because of the addition of several
111 major new pieces of functionality.
113 A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
114 algorithm, has been added. This has a number of advantages for certain cases,
115 though it does run more slowly, and lacks the ability to capture substrings. On
116 the other hand, it does find all matches, not just the first, and it works
117 better for partial matching. The pcrematching man page discusses the
118 differences.
120 The pcretest program has been enhanced so that it can make use of the new
121 pcre_dfa_exec() matching function and the extra features it provides.
123 The distribution now includes a C++ wrapper library. This is built
124 automatically if a C++ compiler is found. The pcrecpp man page discusses this
125 interface.
127 The code itself has been re-organized into many more files, one for each
128 function, so it no longer requires everything to be linked in when static
129 linkage is used. As a consequence, some internal functions have had to have
130 their names exposed. These functions all have names starting with _pcre_. They
131 are undocumented, and are not intended for use by outside callers.
133 The pcregrep program has been enhanced with new functionality such as
134 multiline-matching and options for output more matching context. See the
135 ChangeLog for a complete list of changes to the library and the utility
136 programs.
139 Release 5.0 13-Sep-04
140 ---------------------
142 The licence under which PCRE is released has been changed to the more
143 conventional "BSD" licence.
145 In the code, some bugs have been fixed, and there are also some major changes
146 in this release (which is why I've increased the number to 5.0). Some changes
147 are internal rearrangements, and some provide a number of new facilities. The
148 new features are:
150 1. There's an "automatic callout" feature that inserts callouts before every
151 item in the regex, and there's a new callout field that gives the position
152 in the pattern - useful for debugging and tracing.
154 2. The extra_data structure can now be used to pass in a set of character
155 tables at exec time. This is useful if compiled regex are saved and re-used
156 at a later time when the tables may not be at the same address. If the
157 default internal tables are used, the pointer saved with the compiled
158 pattern is now set to NULL, which means that you don't need to do anything
159 special unless you are using custom tables.
161 3. It is possible, with some restrictions on the content of the regex, to
162 request "partial" matching. A special return code is given if all of the
163 subject string matched part of the regex. This could be useful for testing
164 an input field as it is being typed.
166 4. There is now some optional support for Unicode character properties, which
167 means that the patterns items such as \p{Lu} and \X can now be used. Only
168 the general category properties are supported. If PCRE is compiled with this
169 support, an additional 90K data structure is include, which increases the
170 size of the library dramatically.
172 5. There is support for saving compiled patterns and re-using them later.
174 6. There is support for running regular expressions that were compiled on a
175 different host with the opposite endianness.
177 7. The pcretest program has been extended to accommodate the new features.
179 The main internal rearrangement is that sequences of literal characters are no
180 longer handled as strings. Instead, each character is handled on its own. This
181 makes some UTF-8 handling easier, and makes the support of partial matching
182 possible. Compiled patterns containing long literal strings will be larger as a
183 result of this change; I hope that performance will not be much affected.
186 Release 4.5 01-Dec-03
187 ---------------------
189 Again mainly a bug-fix and tidying release, with only a couple of new features:
191 1. It's possible now to compile PCRE so that it does not use recursive
192 function calls when matching. Instead it gets memory from the heap. This slows
193 things down, but may be necessary on systems with limited stacks.
195 2. UTF-8 string checking has been tightened to reject overlong sequences and to
196 check that a starting offset points to the start of a character. Failure of the
197 latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
199 3. PCRE can now be compiled for systems that use EBCDIC code.
202 Release 4.4 21-Aug-03
203 ---------------------
205 This is mainly a bug-fix and tidying release. The only new feature is that PCRE
206 checks UTF-8 strings for validity by default. There is an option to suppress
207 this, just in case anybody wants that teeny extra bit of performance.
210 Releases 4.1 - 4.3
211 ------------------
213 Sorry, I forgot about updating the NEWS file for these releases. Please take a
214 look at ChangeLog.
217 Release 4.0 17-Feb-03
218 ---------------------
220 There have been a lot of changes for the 4.0 release, adding additional
221 functionality and mending bugs. Below is a list of the highlights of the new
222 functionality. For full details of these features, please consult the
223 documentation. For a complete list of changes, see the ChangeLog file.
225 1. Support for Perl's \Q...\E escapes.
227 2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
228 package. They provide some syntactic sugar for simple cases of "atomic
229 grouping".
231 3. Support for the \G assertion. It is true when the current matching position
232 is at the start point of the match.
234 4. A new feature that provides some of the functionality that Perl provides
235 with (?{...}). The facility is termed a "callout". The way it is done in PCRE
236 is for the caller to provide an optional function, by setting pcre_callout to
237 its entry point. To get the function called, the regex must include (?C) at
238 appropriate points.
240 5. Support for recursive calls to individual subpatterns. This makes it really
241 easy to get totally confused.
243 6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
244 name a group.
246 7. Several extensions to UTF-8 support; it is now fairly complete. There is an
247 option for pcregrep to make it operate in UTF-8 mode.
249 8. The single man page has been split into a number of separate man pages.
250 These also give rise to individual HTML pages which are put in a separate
251 directory. There is an index.html page that lists them all. Some hyperlinking
252 between the pages has been installed.
255 Release 3.5 15-Aug-01
256 ---------------------
258 1. The configuring system has been upgraded to use later versions of autoconf
259 and libtool. By default it builds both a shared and a static library if the OS
260 supports it. You can use --disable-shared or --disable-static on the configure
261 command if you want only one of them.
263 2. The pcretest utility is now installed along with pcregrep because it is
264 useful for users (to test regexs) and by doing this, it automatically gets
265 relinked by libtool. The documentation has been turned into a man page, so
266 there are now .1, .txt, and .html versions in /doc.
268 3. Upgrades to pcregrep:
269 (i) Added long-form option names like gnu grep.
270 (ii) Added --help to list all options with an explanatory phrase.
271 (iii) Added -r, --recursive to recurse into sub-directories.
272 (iv) Added -f, --file to read patterns from a file.
274 4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
275 script, to force use of CR or LF instead of \n in the source. On non-Unix
276 systems, the value can be set in config.h.
278 5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
279 absolute limit. Changed the text of the error message to make this clear, and
280 likewise updated the man page.
282 6. The limit of 99 on the number of capturing subpatterns has been removed.
283 The new limit is 65535, which I hope will not be a "real" limit.
286 Release 3.3 01-Aug-00
287 ---------------------
289 There is some support for UTF-8 character strings. This is incomplete and
290 experimental. The documentation describes what is and what is not implemented.
291 Otherwise, this is just a bug-fixing release.
294 Release 3.0 01-Feb-00
295 ---------------------
297 1. A "configure" script is now used to configure PCRE for Unix systems. It
298 builds a Makefile, a config.h file, and the pcre-config script.
300 2. PCRE is built as a shared library by default.
302 3. There is support for POSIX classes such as [:alpha:].
304 5. There is an experimental recursion feature.
306 ----------------------------------------------------------------------------
309 Please note that there has been a change in the API such that a larger
310 ovector is required at matching time, to provide some additional workspace.
311 The new man page has details. This change was necessary in order to support
312 some of the new functionality in Perl 5.005.
316 Another (I hope this is the last!) change has been made to the API for the
317 pcre_compile() function. An additional argument has been added to make it
318 possible to pass over a pointer to character tables built in the current
319 locale by pcre_maketables(). To use the default tables, this new arguement
320 should be passed as NULL.
324 Yet another (and again I hope this really is the last) change has been made
325 to the API for the pcre_exec() function. An additional argument has been
326 added to make it possible to start the match other than at the start of the
327 subject string. This is important if there are lookbehinds. The new man
328 page has the details, but you just want to convert existing programs, all
329 you need to do is to stick in a new fifth argument to pcre_exec(), with a
330 value of zero. For example, change
332 pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
333 to
334 pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)
336 ****


Name Value
svn:eol-style native
svn:keywords "Author Date Id Revision Url"

  ViewVC Help
Powered by ViewVC 1.1.5