gdb - Local mods (compile)
[dragonfly.git] / contrib / tre / lib / README
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5f2eab64
JM
1This code is structured roughly as follows:
2
3xmalloc.c:
4 - Wrappers for the malloc() functions, for error generation and
5 memory leak checking purposes.
6
7tre-mem.c:
8 - A simple and efficient memory allocator.
9
10tre-stack.c:
11 - Implements a simple stack data structure.
12
13tre-ast.c:
14 - Abstract syntax tree (AST) definitions.
15
16tre-parse.c:
17 - Regexp parser. Parses a POSIX regexp (with TRE extensions) into
18 an abstract syntax tree (AST).
19
20tre-compile.c:
21 - Compiles ASTs to ready-to-use regex objects. Comprised of two parts:
22 * Routine to convert an AST to a tagged AST. A tagged AST has
23 appropriate minimized or maximized tags added to keep track of
24 submatches.
25 * Routine to convert tagged ASTs to tagged nondeterministic state
26 machines (TNFAs) without epsilon transitions (transitions on
27 empty strings).
28
29tre-match-parallel.c:
30 - Parallel TNFA matcher.
31 * The matcher basically takes a string and a TNFA and finds the
32 leftmost longest match and submatches in one pass over the input
33 string. Only the beginning of the input string is scanned until
34 a leftmost match and longest match is found.
35 * The matcher cannot handle back references, but the worst case
36 time consumption is O(l) where l is the length of the input
37 string. The space consumption is constant.
38
39tre-match-backtrack.c:
40 - A traditional backtracking matcher.
41 * Like the parallel matcher, takes a string and a TNFA and finds
42 the leftmost longest match and submatches. Portions of the
43 input string may (and usually are) scanned multiple times.
44 * Can handle back references. The worst case time consumption,
45 however, is O(k^l) where k is some constant and l is the length
46 of the input string. The worst case space consumption is O(l).
47
48tre-match-approx.c:
49 - Approximate parallel TNFA matcher.
50 * Finds the leftmost and longest match and submatches in one pass
51 over the input string. The match may contain errors. Each
52 missing, substituted, or extra character in the match increases
53 the cost of the match. A maximum cost for the returned match
54 can be given. The cost of the found match is returned.
55 * Cannot handle back references. The space and time consumption
56 bounds are the same as for the parallel exact matcher, but
57 in general this matcher is slower than the exact matcher.
58
59regcomp.c:
60 - Implementation of the regcomp() family of functions as simple
61 wrappers for tre_compile().
62
63regexec.c:
64 - Implementation of the regexec() family of functions.
65 * The appropriate matcher is dispatched according to the
66 features used in the compiled regex object.
67
68regerror.c:
69 - Implements the regerror() function.