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Sat Feb 24 21:40:37 2007 UTC (7 years, 1 month ago) by nigel
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Load pcre-5.0 into code/trunk.

1 nigel 41 News about PCRE releases
2     ------------------------
3    
4 nigel 75 Release 5.0 13-Sep-04
5     ---------------------
6    
7     The licence under which PCRE is released has been changed to the more
8     conventional "BSD" licence.
9    
10     In the code, some bugs have been fixed, and there are also some major changes
11     in this release (which is why I've increased the number to 5.0). Some changes
12     are internal rearrangements, and some provide a number of new facilities. The
13     new features are:
14    
15     1. There's an "automatic callout" feature that inserts callouts before every
16     item in the regex, and there's a new callout field that gives the position
17     in the pattern - useful for debugging and tracing.
18    
19     2. The extra_data structure can now be used to pass in a set of character
20     tables at exec time. This is useful if compiled regex are saved and re-used
21     at a later time when the tables may not be at the same address. If the
22     default internal tables are used, the pointer saved with the compiled
23     pattern is now set to NULL, which means that you don't need to do anything
24     special unless you are using custom tables.
25    
26     3. It is possible, with some restrictions on the content of the regex, to
27     request "partial" matching. A special return code is given if all of the
28     subject string matched part of the regex. This could be useful for testing
29     an input field as it is being typed.
30    
31     4. There is now some optional support for Unicode character properties, which
32     means that the patterns items such as \p{Lu} and \X can now be used. Only
33     the general category properties are supported. If PCRE is compiled with this
34     support, an additional 90K data structure is include, which increases the
35     size of the library dramatically.
36    
37     5. There is support for saving compiled patterns and re-using them later.
38    
39     6. There is support for running regular expressions that were compiled on a
40     different host with the opposite endianness.
41    
42     7. The pcretest program has been extended to accommodate the new features.
43    
44     The main internal rearrangement is that sequences of literal characters are no
45     longer handled as strings. Instead, each character is handled on its own. This
46     makes some UTF-8 handling easier, and makes the support of partial matching
47     possible. Compiled patterns containing long literal strings will be larger as a
48     result of this change; I hope that performance will not be much affected.
49    
50    
51 nigel 73 Release 4.5 01-Dec-03
52     ---------------------
53    
54     Again mainly a bug-fix and tidying release, with only a couple of new features:
55    
56     1. It's possible now to compile PCRE so that it does not use recursive
57     function calls when matching. Instead it gets memory from the heap. This slows
58     things down, but may be necessary on systems with limited stacks.
59    
60     2. UTF-8 string checking has been tightened to reject overlong sequences and to
61     check that a starting offset points to the start of a character. Failure of the
62     latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
63    
64     3. PCRE can now be compiled for systems that use EBCDIC code.
65    
66    
67 nigel 71 Release 4.4 21-Aug-03
68     ---------------------
69    
70     This is mainly a bug-fix and tidying release. The only new feature is that PCRE
71     checks UTF-8 strings for validity by default. There is an option to suppress
72     this, just in case anybody wants that teeny extra bit of performance.
73    
74    
75     Releases 4.1 - 4.3
76     ------------------
77    
78     Sorry, I forgot about updating the NEWS file for these releases. Please take a
79     look at ChangeLog.
80    
81    
82 nigel 63 Release 4.0 17-Feb-03
83     ---------------------
84    
85     There have been a lot of changes for the 4.0 release, adding additional
86     functionality and mending bugs. Below is a list of the highlights of the new
87     functionality. For full details of these features, please consult the
88     documentation. For a complete list of changes, see the ChangeLog file.
89    
90     1. Support for Perl's \Q...\E escapes.
91    
92     2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
93     package. They provide some syntactic sugar for simple cases of "atomic
94     grouping".
95    
96     3. Support for the \G assertion. It is true when the current matching position
97     is at the start point of the match.
98    
99     4. A new feature that provides some of the functionality that Perl provides
100     with (?{...}). The facility is termed a "callout". The way it is done in PCRE
101     is for the caller to provide an optional function, by setting pcre_callout to
102     its entry point. To get the function called, the regex must include (?C) at
103     appropriate points.
104    
105     5. Support for recursive calls to individual subpatterns. This makes it really
106     easy to get totally confused.
107    
108     6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
109     name a group.
110    
111     7. Several extensions to UTF-8 support; it is now fairly complete. There is an
112     option for pcregrep to make it operate in UTF-8 mode.
113    
114     8. The single man page has been split into a number of separate man pages.
115     These also give rise to individual HTML pages which are put in a separate
116     directory. There is an index.html page that lists them all. Some hyperlinking
117     between the pages has been installed.
118    
119    
120 nigel 53 Release 3.5 15-Aug-01
121     ---------------------
122    
123     1. The configuring system has been upgraded to use later versions of autoconf
124     and libtool. By default it builds both a shared and a static library if the OS
125     supports it. You can use --disable-shared or --disable-static on the configure
126     command if you want only one of them.
127    
128     2. The pcretest utility is now installed along with pcregrep because it is
129     useful for users (to test regexs) and by doing this, it automatically gets
130     relinked by libtool. The documentation has been turned into a man page, so
131     there are now .1, .txt, and .html versions in /doc.
132    
133     3. Upgrades to pcregrep:
134     (i) Added long-form option names like gnu grep.
135     (ii) Added --help to list all options with an explanatory phrase.
136     (iii) Added -r, --recursive to recurse into sub-directories.
137     (iv) Added -f, --file to read patterns from a file.
138    
139     4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
140     script, to force use of CR or LF instead of \n in the source. On non-Unix
141     systems, the value can be set in config.h.
142    
143     5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
144     absolute limit. Changed the text of the error message to make this clear, and
145     likewise updated the man page.
146    
147     6. The limit of 99 on the number of capturing subpatterns has been removed.
148     The new limit is 65535, which I hope will not be a "real" limit.
149    
150    
151 nigel 49 Release 3.3 01-Aug-00
152     ---------------------
153    
154     There is some support for UTF-8 character strings. This is incomplete and
155     experimental. The documentation describes what is and what is not implemented.
156     Otherwise, this is just a bug-fixing release.
157    
158    
159 nigel 43 Release 3.0 01-Feb-00
160     ---------------------
161 nigel 41
162 nigel 43 1. A "configure" script is now used to configure PCRE for Unix systems. It
163     builds a Makefile, a config.h file, and the pcre-config script.
164    
165     2. PCRE is built as a shared library by default.
166    
167     3. There is support for POSIX classes such as [:alpha:].
168    
169     5. There is an experimental recursion feature.
170    
171 nigel 41 ----------------------------------------------------------------------------
172     IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00
173    
174     Please note that there has been a change in the API such that a larger
175     ovector is required at matching time, to provide some additional workspace.
176     The new man page has details. This change was necessary in order to support
177     some of the new functionality in Perl 5.005.
178    
179     IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.00
180    
181     Another (I hope this is the last!) change has been made to the API for the
182     pcre_compile() function. An additional argument has been added to make it
183     possible to pass over a pointer to character tables built in the current
184     locale by pcre_maketables(). To use the default tables, this new arguement
185     should be passed as NULL.
186    
187     IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.05
188    
189     Yet another (and again I hope this really is the last) change has been made
190     to the API for the pcre_exec() function. An additional argument has been
191     added to make it possible to start the match other than at the start of the
192     subject string. This is important if there are lookbehinds. The new man
193     page has the details, but you just want to convert existing programs, all
194     you need to do is to stick in a new fifth argument to pcre_exec(), with a
195     value of zero. For example, change
196    
197     pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
198     to
199     pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)
200    
201     ****

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