Contents of /code/trunk/NEWS

News about PCRE releases
------------------------


Release 7.1 12-Mar-07
---------------------

There are no new features in this release. A few bugs are fixed (see ChangeLog
for details), but the major change is a complete re-implementation of the build
system. This now has full Autotools support and so is now "standard" in some
sense. It should help with compiling PCRE in a wide variety of environments.


Release 7.0 19-Dec-06
---------------------

This release has a new major number because there have been some internal
upheavals to facilitate the addition of new optimizations and other facilities,
and to make subsequent maintenance and extension easier. Compilation is likely
to be a bit slower, but there should be no major effect on runtime performance.
Previously compiled patterns are NOT upwards compatible with this release. If
you have saved compiled patterns from a previous release, you will have to
re-compile them. Important changes that are visible to users are:

1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
   some more scripts.

2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
   sequence as a newline.

3. The \R escape matches a single Unicode newline sequence as a single unit.

4. New features that will appear in Perl 5.10 are now in PCRE. These include
   alternative Perl syntax for named parentheses, and Perl syntax for
   recursion.

5. The C++ wrapper interface has been extended by the addition of a
   QuoteMeta function and the ability to allow copy construction and
   assignment.

For a complete list of changes, see the ChangeLog file.


Release 6.7 04-Jul-06
---------------------

The main additions to this release are the ability to use the same name for
multiple sets of parentheses, and support for CRLF line endings in both the
library and pcregrep (and in pcretest for testing).

Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
significantly reduced for certain subject strings.


Release 6.5 01-Feb-06
---------------------

Important changes in this release:

1. A number of new features have been added to pcregrep.

2. The Unicode property tables have been updated to Unicode 4.1.0, and the
   supported properties have been extended with script names such as "Arabic",
   and the derived properties "Any" and "L&". This has necessitated a change to
   the interal format of compiled patterns. Any saved compiled patterns that
   use \p or \P must be recompiled.

3. The specification of recursion in patterns has been changed so that all
   recursive subpatterns are automatically treated as atomic groups. Thus, for
   example, (?R) is treated as if it were (?>(?R)). This is necessary because
   otherwise there are situations where recursion does not work.

See the ChangeLog for a complete list of changes, which include a number of bug
fixes and tidies.


Release 6.0 07-Jun-05
---------------------

The release number has been increased to 6.0 because of the addition of several
major new pieces of functionality.

A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
algorithm, has been added. This has a number of advantages for certain cases,
though it does run more slowly, and lacks the ability to capture substrings. On
the other hand, it does find all matches, not just the first, and it works
better for partial matching. The pcrematching man page discusses the
differences.

The pcretest program has been enhanced so that it can make use of the new
pcre_dfa_exec() matching function and the extra features it provides.

The distribution now includes a C++ wrapper library. This is built
automatically if a C++ compiler is found. The pcrecpp man page discusses this
interface.

The code itself has been re-organized into many more files, one for each
function, so it no longer requires everything to be linked in when static
linkage is used. As a consequence, some internal functions have had to have
their names exposed. These functions all have names starting with _pcre_. They
are undocumented, and are not intended for use by outside callers.

The pcregrep program has been enhanced with new functionality such as
multiline-matching and options for output more matching context. See the
ChangeLog for a complete list of changes to the library and the utility
programs.


Release 5.0 13-Sep-04
---------------------

The licence under which PCRE is released has been changed to the more
conventional "BSD" licence.

In the code, some bugs have been fixed, and there are also some major changes
in this release (which is why I've increased the number to 5.0). Some changes
are internal rearrangements, and some provide a number of new facilities. The
new features are:

1. There's an "automatic callout" feature that inserts callouts before every
   item in the regex, and there's a new callout field that gives the position
   in the pattern - useful for debugging and tracing.

2. The extra_data structure can now be used to pass in a set of character
   tables at exec time. This is useful if compiled regex are saved and re-used
   at a later time when the tables may not be at the same address. If the
   default internal tables are used, the pointer saved with the compiled
   pattern is now set to NULL, which means that you don't need to do anything
   special unless you are using custom tables.

3. It is possible, with some restrictions on the content of the regex, to
   request "partial" matching. A special return code is given if all of the
   subject string matched part of the regex. This could be useful for testing
   an input field as it is being typed.

4. There is now some optional support for Unicode character properties, which
   means that the patterns items such as \p{Lu} and \X can now be used. Only
   the general category properties are supported. If PCRE is compiled with this
   support, an additional 90K data structure is include, which increases the
   size of the library dramatically.

5. There is support for saving compiled patterns and re-using them later.

6. There is support for running regular expressions that were compiled on a
   different host with the opposite endianness.

7. The pcretest program has been extended to accommodate the new features.

The main internal rearrangement is that sequences of literal characters are no
longer handled as strings. Instead, each character is handled on its own. This
makes some UTF-8 handling easier, and makes the support of partial matching
possible. Compiled patterns containing long literal strings will be larger as a
result of this change; I hope that performance will not be much affected.


Release 4.5 01-Dec-03
---------------------

Again mainly a bug-fix and tidying release, with only a couple of new features:

1. It's possible now to compile PCRE so that it does not use recursive
function calls when matching. Instead it gets memory from the heap. This slows
things down, but may be necessary on systems with limited stacks.

2. UTF-8 string checking has been tightened to reject overlong sequences and to
check that a starting offset points to the start of a character. Failure of the
latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.

3. PCRE can now be compiled for systems that use EBCDIC code.


Release 4.4 21-Aug-03
---------------------

This is mainly a bug-fix and tidying release. The only new feature is that PCRE
checks UTF-8 strings for validity by default. There is an option to suppress
this, just in case anybody wants that teeny extra bit of performance.


Releases 4.1 - 4.3
------------------

Sorry, I forgot about updating the NEWS file for these releases. Please take a
look at ChangeLog.


Release 4.0 17-Feb-03
---------------------

There have been a lot of changes for the 4.0 release, adding additional
functionality and mending bugs. Below is a list of the highlights of the new
functionality. For full details of these features, please consult the
documentation. For a complete list of changes, see the ChangeLog file.

1. Support for Perl's \Q...\E escapes.

2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
package. They provide some syntactic sugar for simple cases of "atomic
grouping".

3. Support for the \G assertion. It is true when the current matching position
is at the start point of the match.

4. A new feature that provides some of the functionality that Perl provides
with (?{...}). The facility is termed a "callout". The way it is done in PCRE
is for the caller to provide an optional function, by setting pcre_callout to
its entry point. To get the function called, the regex must include (?C) at
appropriate points.

5. Support for recursive calls to individual subpatterns. This makes it really
easy to get totally confused.

6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
name a group.

7. Several extensions to UTF-8 support; it is now fairly complete. There is an
option for pcregrep to make it operate in UTF-8 mode.

8. The single man page has been split into a number of separate man pages.
These also give rise to individual HTML pages which are put in a separate
directory. There is an index.html page that lists them all. Some hyperlinking
between the pages has been installed.


Release 3.5 15-Aug-01
---------------------

1. The configuring system has been upgraded to use later versions of autoconf
and libtool. By default it builds both a shared and a static library if the OS
supports it. You can use --disable-shared or --disable-static on the configure
command if you want only one of them.

2. The pcretest utility is now installed along with pcregrep because it is
useful for users (to test regexs) and by doing this, it automatically gets
relinked by libtool. The documentation has been turned into a man page, so
there are now .1, .txt, and .html versions in /doc.

3. Upgrades to pcregrep:
   (i)   Added long-form option names like gnu grep.
   (ii)  Added --help to list all options with an explanatory phrase.
   (iii) Added -r, --recursive to recurse into sub-directories.
   (iv)  Added -f, --file to read patterns from a file.

4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
script, to force use of CR or LF instead of \n in the source. On non-Unix
systems, the value can be set in config.h.

5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
absolute limit. Changed the text of the error message to make this clear, and
likewise updated the man page.

6. The limit of 99 on the number of capturing subpatterns has been removed.
The new limit is 65535, which I hope will not be a "real" limit.


Release 3.3 01-Aug-00
---------------------

There is some support for UTF-8 character strings. This is incomplete and
experimental. The documentation describes what is and what is not implemented.
Otherwise, this is just a bug-fixing release.


Release 3.0 01-Feb-00
---------------------

1. A "configure" script is now used to configure PCRE for Unix systems. It
builds a Makefile, a config.h file, and the pcre-config script.

2. PCRE is built as a shared library by default.

3. There is support for POSIX classes such as [:alpha:].

5. There is an experimental recursion feature.

----------------------------------------------------------------------------
          IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00

Please note that there has been a change in the API such that a larger
ovector is required at matching time, to provide some additional workspace.
The new man page has details. This change was necessary in order to support
some of the new functionality in Perl 5.005.

          IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.00

Another (I hope this is the last!) change has been made to the API for the
pcre_compile() function. An additional argument has been added to make it
possible to pass over a pointer to character tables built in the current
locale by pcre_maketables(). To use the default tables, this new arguement
should be passed as NULL.

          IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.05

Yet another (and again I hope this really is the last) change has been made
to the API for the pcre_exec() function. An additional argument has been
added to make it possible to start the match other than at the start of the
subject string. This is important if there are lookbehinds. The new man
page has the details, but you just want to convert existing programs, all
you need to do is to stick in a new fifth argument to pcre_exec(), with a
value of zero. For example, change

  pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
to
  pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)

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