New "re" regular expression support.

This code is written by Philip Hazel and Andrew Kuchling.
It requires a new "re.py" module, too.

Modules/pcre-internal.h

+/*************************************************
+*      Perl-Compatible Regular Expressions       *
+*************************************************/
+
+
+#define PCRE_VERSION       "0.95 23-Sep-1997"
+
+
+/* This is a library of functions to support regular expressions whose syntax
+and semantics are as close as possible to those of the Perl 5 language. See
+the file Tech.Notes for some information on the internals.
+
+Written by: Philip Hazel <ph10@cam.ac.uk>
+
+           Copyright (c) 1997 University of Cambridge
+
+-----------------------------------------------------------------------------
+Permission is granted to anyone to use this software for any purpose on any
+computer system, and to redistribute it freely, subject to the following
+restrictions:
+
+1. This software is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+2. The origin of this software must not be misrepresented, either by
+   explicit claim or by omission.
+
+3. Altered versions must be plainly marked as such, and must not be
+   misrepresented as being the original software.
+-----------------------------------------------------------------------------
+*/
+
+/* This header contains definitions that are shared between the different
+modules, but which are not relevant to the outside. */
+
+/* Standard C headers plus the external interface definition */
+
+#include <ctype.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "pcre.h"
+
+/* Private options flags start at the most significant end of the byte. The
+public options defined in pcre.h start at the least significant end. Make sure
+they don't overlap! */
+
+#define PCRE_FIRSTSET  0x80          /* first_char is set */
+#define PCRE_STARTLINE 0x40          /* start after \n for multiline */
+
+/* Options for the "extra" block produced by pcre_study(). */
+
+#define PCRE_STUDY_CASELESS 0x01     /* study was caseless */
+#define PCRE_STUDY_MAPPED   0x20     /* a map of starting chars exists */
+
+/* Masks for identifying the public options: all permitted at compile time,
+only some permitted at run or study time. */
+
+#ifdef FOR_PYTHON
+#define PUBLIC_OPTIONS \
+  (PCRE_CASELESS|PCRE_EXTENDED|PCRE_ANCHORED|PCRE_MULTILINE|PCRE_DOTALL)
+#else
+#define PUBLIC_OPTIONS \
+  (PCRE_CASELESS|PCRE_EXTENDED|PCRE_ANCHORED|PCRE_MULTILINE)
+#endif
+#define PUBLIC_EXEC_OPTIONS (PCRE_CASELESS|PCRE_ANCHORED|PCRE_MULTILINE)
+#define PUBLIC_STUDY_OPTIONS (PCRE_CASELESS)
+
+/* Magic number to provide a small check against being handed junk. */
+
+#define MAGIC_NUMBER  0x50435245   /* 'PCRE' */
+
+/* Miscellaneous definitions */
+
+typedef int BOOL;
+
+#define FALSE   0
+#define TRUE    1
+
+/* Flags for character classes - see also class_ops table below. */
+
+#define CLASS_DIGITS         0x01
+#define CLASS_NOT_DIGITS     0x02
+#define CLASS_WHITESPACE     0x04
+#define CLASS_NOT_WHITESPACE 0x08
+#define CLASS_WORD           0x10
+#define CLASS_NOT_WORD       0x20
+
+/* These are escaped items that aren't just an encoding of a particular data
+value such as \n. They must have non-zero values, as check_escape() returns
+their negation. Also, they must appear in the same order as in the opcode
+definitions below, up to ESC_Z. The final one must be ESC_REF as subsequent
+values are used for \1, \2, \3, etc. There is a test in the code for an escape
+greater than ESC_b and less than ESC_Z to detect the types that may be
+repeated. If any new escapes are put in-between that don't consume a character,
+that code will have to change. */
+
+enum { ESC_A = 1, ESC_B, ESC_b, ESC_D, ESC_d, ESC_S, ESC_s, ESC_W, ESC_w,
+       ESC_Z, ESC_REF };
+
+/* Opcode table: OP_BRA must be last, as all values >= it are used for brackets
+that extract substrings. Starting from 1 (i.e. after OP_END), the values up to
+OP_EOL must correspond in order to the list of escapes immediately above. */
+
+enum {
+  OP_END,            /* End of pattern */
+
+  /* Values corresponding to backslashed metacharacters */
+
+  OP_SOD,            /* Start of data: \A */
+  OP_NOT_WORD_BOUNDARY,  /* \W */
+  OP_WORD_BOUNDARY,      /* \w */
+  OP_NOT_DIGIT,          /* \D */
+  OP_DIGIT,              /* \d */
+  OP_NOT_WHITESPACE,     /* \S */
+  OP_WHITESPACE,         /* \s */
+  OP_NOT_WORDCHAR,       /* \W */
+  OP_WORDCHAR,           /* \w */
+  OP_EOD,            /* End of data: or \Z. This must always be the last
+                        of the backslashed meta values. */
+
+  OP_CIRC,           /* Start of line - varies with multiline switch */
+  OP_DOLL,           /* End of line - varies with multiline switch */
+  OP_ANY,            /* Match any character */
+  OP_CHARS,          /* Match string of characters */
+
+  OP_STAR,           /* The maximizing and minimizing versions of */
+  OP_MINSTAR,        /* all these opcodes must come in pairs, with */
+  OP_PLUS,           /* the minimizing one second. */
+  OP_MINPLUS,        /* This first set applies to single characters */
+  OP_QUERY,
+  OP_MINQUERY,
+  OP_UPTO,           /* From 0 to n matches. */
+  OP_MINUPTO,
+  OP_EXACT,          /* Exactly n matches. */
+
+  OP_TYPESTAR,       /* The maximizing and minimizing versions of */
+  OP_TYPEMINSTAR,    /* all these opcodes must come in pairs, with */
+  OP_TYPEPLUS,       /* the minimizing one second. These codes must */
+  OP_TYPEMINPLUS,    /* be in exactly the same order as those above. */
+  OP_TYPEQUERY,      /* This set applies to character types such as \d */
+  OP_TYPEMINQUERY,
+  OP_TYPEUPTO,
+  OP_TYPEMINUPTO,
+  OP_TYPEEXACT,
+
+  OP_CRSTAR,         /* The maximizing and minimizing versions of */
+  OP_CRMINSTAR,      /* all these opcodes must come in pairs, with */
+  OP_CRPLUS,         /* the minimizing one second. These codes must */
+  OP_CRMINPLUS,      /* be in exactly the same order as those above. */
+  OP_CRQUERY,        /* These are for character classes and back refs */
+  OP_CRMINQUERY,
+  OP_CRRANGE,        /* These are different to the two seta above. */
+  OP_CRMINRANGE,
+
+  OP_CLASS,          /* Match a character class */
+  OP_NEGCLASS,       /* Don't match a character class */
+  OP_REF,            /* Match a back reference */
+
+  OP_ALT,            /* Start of alternation */
+  OP_KET,            /* End of group that doesn't have an unbounded repeat */
+  OP_KETRMAX,        /* These two must remain together and in this */
+  OP_KETRMIN,        /* order. They are for groups the repeat for ever. */
+
+  OP_ASSERT,
+  OP_ASSERT_NOT,
+
+  OP_BRAZERO,        /* These two must remain together and in this */
+  OP_BRAMINZERO,     /* order. */
+
+  OP_BRA             /* This and greater values are used for brackets that
+                        extract substrings. */
+};
+
+/* The highest extraction number. This is limited by the number of opcodes
+left after OP_BRA, i.e. 255 - OP_BRA. We actually set it somewhat lower. */
+
+#define EXTRACT_MAX  99
+
+/* All character handling must be done as unsigned characters. Otherwise there
+are problems with top-bit-set characters and functions such as isspace().
+However, we leave the interface to the outside world as char *, because that
+should make things easier for callers. We define a short type for unsigned char
+to save lots of typing. I tried "uchar", but it causes problems on Digital
+Unix, where it is defined in sys/types, so use "uschar" instead. */
+
+typedef unsigned char uschar;
+
+/* The real format of the start of the pcre block; the actual code vector
+runs on as long as necessary after the end. */
+
+typedef struct real_pcre {
+  unsigned int  magic_number;
+  unsigned char options;
+  unsigned char top_bracket;
+  unsigned char first_char;
+  unsigned char code[1];
+} real_pcre;
+
+/* The real format of the extra block returned by pcre_study(). */
+
+typedef struct real_pcre_extra {
+  unsigned char options;
+  unsigned char start_bits[32];
+} real_pcre_extra;
+
+/* Global tables from pcre-chartables.c */
+
+extern uschar pcre_lcc[];
+extern uschar pcre_ucc[];
+extern uschar pcre_ctypes[];
+
+/* Bit definitions for entries in pcre_ctypes[]. */
+
+#define ctype_space   0x01
+#define ctype_digit   0x02
+#define ctype_xdigit  0x04
+#define ctype_word    0x08   /* alphameric or '_' */
+#ifdef FOR_PYTHON
+#define ctype_odigit  0x10   /* Octal digits */
+#endif
+#define ctype_meta    0x80   /* regexp meta char or zero (end pattern) */
+
+/* End of pcre-internal.h */

Modules/pcre.h

+/*************************************************
+*       Perl-Compatible Regular Expressions      *
+*************************************************/
+
+/* Copyright (c) 1997 University of Cambridge */
+
+/* Have to include stdlib.h in order to ensure that size_t is defined;
+it is needed in there for malloc. */
+
+#ifndef PCRE_H
+#define PCRE_H
+
+#include <stdlib.h>
+#ifdef FOR_PYTHON
+#include "Python.h"
+#endif
+
+/* Options */
+
+#define PCRE_CASELESS     0x01
+#define PCRE_EXTENDED     0x02
+#define PCRE_ANCHORED     0x04
+#define PCRE_MULTILINE    0x08
+#define PCRE_DOTALL       0x10
+
+/* Exec-time error codes */
+
+#define PCRE_ERROR_NOMATCH        (-1)
+#define PCRE_ERROR_BADREF         (-2)
+#define PCRE_ERROR_NULL           (-3)
+#define PCRE_ERROR_BADOPTION      (-4)
+#define PCRE_ERROR_BADMAGIC       (-5)
+#define PCRE_ERROR_UNKNOWN_NODE   (-6)
+
+/* Types */
+
+typedef void pcre;
+typedef void pcre_extra;
+
+/* Store get and free functions. These can be set to alternative malloc/free
+functions if required. */
+
+extern void *(*pcre_malloc)(size_t);
+extern void  (*pcre_free)(void *);
+
+/* Functions */
+
+#ifdef FOR_PYTHON
+extern pcre *pcre_compile(char *, int, char **, int *, PyObject *);
+#else
+extern pcre *pcre_compile(char *, int, char **, int *);
+#endif
+extern int pcre_exec(pcre *, pcre_extra *, char *, int, int, int *, int);
+extern int pcre_info(pcre *, int *, int *);
+extern pcre_extra *pcre_study(pcre *, int, char **);
+extern char *pcre_version(void);
+
+#endif /* ifndef PCRE_H */
+/* End of pcre.h */