185 lines
7.9 KiB
C
185 lines
7.9 KiB
C
/* Definitions for data structures callers pass the regex library.
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Copyright (C) 1985, 1989 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 1, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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In other words, you are welcome to use, share and improve this program.
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You are forbidden to forbid anyone else to use, share and improve
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what you give them. Help stamp out software-hoarding! */
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/* Define number of parens for which we record the beginnings and ends.
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This affects how much space the `struct re_registers' type takes up. */
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#ifndef RE_NREGS
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#define RE_NREGS 10
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#endif
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/* These bits are used in the obscure_syntax variable to choose among
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alternative regexp syntaxes. */
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/* 1 means plain parentheses serve as grouping, and backslash
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parentheses are needed for literal searching.
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0 means backslash-parentheses are grouping, and plain parentheses
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are for literal searching. */
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#define RE_NO_BK_PARENS 1
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/* 1 means plain | serves as the "or"-operator, and \| is a literal.
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0 means \| serves as the "or"-operator, and | is a literal. */
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#define RE_NO_BK_VBAR 2
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/* 0 means plain + or ? serves as an operator, and \+, \? are literals.
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1 means \+, \? are operators and plain +, ? are literals. */
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#define RE_BK_PLUS_QM 4
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/* 1 means | binds tighter than ^ or $.
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0 means the contrary. */
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#define RE_TIGHT_VBAR 8
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/* 1 means treat \n as an _OR operator
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0 means treat it as a normal character */
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#define RE_NEWLINE_OR 16
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/* 0 means that a special characters (such as *, ^, and $) always have
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their special meaning regardless of the surrounding context.
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1 means that special characters may act as normal characters in some
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contexts. Specifically, this applies to:
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^ - only special at the beginning, or after ( or |
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$ - only special at the end, or before ) or |
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*, +, ? - only special when not after the beginning, (, or | */
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#define RE_CONTEXT_INDEP_OPS 32
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/* Now define combinations of bits for the standard possibilities. */
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#define RE_SYNTAX_AWK (RE_NO_BK_PARENS | RE_NO_BK_VBAR | RE_CONTEXT_INDEP_OPS)
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#define RE_SYNTAX_EGREP (RE_SYNTAX_AWK | RE_NEWLINE_OR)
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#define RE_SYNTAX_GREP (RE_BK_PLUS_QM | RE_NEWLINE_OR)
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#define RE_SYNTAX_EMACS 0
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/* This data structure is used to represent a compiled pattern. */
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struct re_pattern_buffer
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{
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char *buffer; /* Space holding the compiled pattern commands. */
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int allocated; /* Size of space that buffer points to */
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int used; /* Length of portion of buffer actually occupied */
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char *fastmap; /* Pointer to fastmap, if any, or zero if none. */
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/* re_search uses the fastmap, if there is one,
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to skip quickly over totally implausible characters */
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char *translate; /* Translate table to apply to all characters before comparing.
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Or zero for no translation.
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The translation is applied to a pattern when it is compiled
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and to data when it is matched. */
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char fastmap_accurate;
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/* Set to zero when a new pattern is stored,
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set to one when the fastmap is updated from it. */
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char can_be_null; /* Set to one by compiling fastmap
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if this pattern might match the null string.
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It does not necessarily match the null string
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in that case, but if this is zero, it cannot.
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2 as value means can match null string
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but at end of range or before a character
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listed in the fastmap. */
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};
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/* Structure to store "register" contents data in.
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Pass the address of such a structure as an argument to re_match, etc.,
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if you want this information back.
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start[i] and end[i] record the string matched by \( ... \) grouping i,
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for i from 1 to RE_NREGS - 1.
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start[0] and end[0] record the entire string matched. */
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struct re_registers
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{
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int start[RE_NREGS];
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int end[RE_NREGS];
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};
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/* These are the command codes that appear in compiled regular expressions, one per byte.
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Some command codes are followed by argument bytes.
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A command code can specify any interpretation whatever for its arguments.
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Zero-bytes may appear in the compiled regular expression. */
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enum regexpcode
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{
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unused,
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exactn, /* followed by one byte giving n, and then by n literal bytes */
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begline, /* fails unless at beginning of line */
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endline, /* fails unless at end of line */
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jump, /* followed by two bytes giving relative address to jump to */
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on_failure_jump, /* followed by two bytes giving relative address of place
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to resume at in case of failure. */
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finalize_jump, /* Throw away latest failure point and then jump to address. */
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maybe_finalize_jump, /* Like jump but finalize if safe to do so.
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This is used to jump back to the beginning
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of a repeat. If the command that follows
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this jump is clearly incompatible with the
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one at the beginning of the repeat, such that
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we can be sure that there is no use backtracking
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out of repetitions already completed,
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then we finalize. */
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dummy_failure_jump, /* jump, and push a dummy failure point.
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This failure point will be thrown away
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if an attempt is made to use it for a failure.
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A + construct makes this before the first repeat. */
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anychar, /* matches any one character */
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charset, /* matches any one char belonging to specified set.
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First following byte is # bitmap bytes.
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Then come bytes for a bit-map saying which chars are in.
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Bits in each byte are ordered low-bit-first.
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A character is in the set if its bit is 1.
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A character too large to have a bit in the map
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is automatically not in the set */
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charset_not, /* similar but match any character that is NOT one of those specified */
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start_memory, /* starts remembering the text that is matched
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and stores it in a memory register.
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followed by one byte containing the register number.
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Register numbers must be in the range 0 through NREGS. */
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stop_memory, /* stops remembering the text that is matched
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and stores it in a memory register.
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followed by one byte containing the register number.
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Register numbers must be in the range 0 through NREGS. */
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duplicate, /* match a duplicate of something remembered.
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Followed by one byte containing the index of the memory register. */
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before_dot, /* Succeeds if before dot */
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at_dot, /* Succeeds if at dot */
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after_dot, /* Succeeds if after dot */
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begbuf, /* Succeeds if at beginning of buffer */
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endbuf, /* Succeeds if at end of buffer */
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wordchar, /* Matches any word-constituent character */
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notwordchar, /* Matches any char that is not a word-constituent */
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wordbeg, /* Succeeds if at word beginning */
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wordend, /* Succeeds if at word end */
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wordbound, /* Succeeds if at a word boundary */
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notwordbound, /* Succeeds if not at a word boundary */
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syntaxspec, /* Matches any character whose syntax is specified.
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followed by a byte which contains a syntax code, Sword or such like */
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notsyntaxspec /* Matches any character whose syntax differs from the specified. */
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};
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extern char *re_compile_pattern ();
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/* Is this really advertised? */
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extern void re_compile_fastmap ();
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extern int re_search (), re_search_2 ();
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extern int re_match (), re_match_2 ();
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/* 4.2 bsd compatibility (yuck) */
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extern char *re_comp ();
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extern int re_exec ();
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#ifdef SYNTAX_TABLE
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extern char *re_syntax_table;
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#endif
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