1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- G N A T . R E G E X P --
-- --
-- S p e c --
-- --
-- Copyright (C) 1998-2003 Ada Core Technologies, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNAT is maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
-- Simple Regular expression matching
-- This package provides a simple implementation of a regular expression
-- pattern matching algorithm, using a subset of the syntax of regular
-- expressions copied from familiar Unix style utilities.
------------------------------------------------------------
-- Summary of Pattern Matching Packages in GNAT Hierarchy --
------------------------------------------------------------
-- There are three related packages that perform pattern maching functions.
-- the following is an outline of these packages, to help you determine
-- which is best for your needs.
-- GNAT.Regexp (files g-regexp.ads/g-regexp.adb)
-- This is a simple package providing Unix-style regular expression
-- matching with the restriction that it matches entire strings. It
-- is particularly useful for file name matching, and in particular
-- it provides "globbing patterns" that are useful in implementing
-- unix or DOS style wild card matching for file names.
-- GNAT.Regpat (files g-regpat.ads/g-regpat.adb)
-- This is a more complete implementation of Unix-style regular
-- expressions, copied from the original V7 style regular expression
-- library written in C by Henry Spencer. It is functionally the
-- same as this library, and uses the same internal data structures
-- stored in a binary compatible manner.
-- GNAT.Spitbol.Patterns (files g-spipat.ads/g-spipat.adb)
-- This is a completely general patterm matching package based on the
-- pattern language of SNOBOL4, as implemented in SPITBOL. The pattern
-- language is modeled on context free grammars, with context sensitive
-- extensions that provide full (type 0) computational capabilities.
with Ada.Finalization;
package GNAT.Regexp is
-- The regular expression must first be compiled, using the Compile
-- function, which creates a finite state matching table, allowing
-- very fast matching once the expression has been compiled.
-- The following is the form of a regular expression, expressed in Ada
-- reference manual style BNF is as follows
-- regexp ::= term
-- regexp ::= term | term -- alternation (term or term ...)
-- term ::= item
-- term ::= item item ... -- concatenation (item then item)
-- item ::= elmt -- match elmt
-- item ::= elmt * -- zero or more elmt's
-- item ::= elmt + -- one or more elmt's
-- item ::= elmt ? -- matches elmt or nothing
-- elmt ::= nchr -- matches given character
-- elmt ::= [nchr nchr ...] -- matches any character listed
-- elmt ::= [^ nchr nchr ...] -- matches any character not listed
-- elmt ::= [char - char] -- matches chars in given range
-- elmt ::= . -- matches any single character
-- elmt ::= ( regexp ) -- parens used for grouping
-- char ::= any character, including special characters
-- nchr ::= any character except \()[].*+?^ or \char to match char
-- ... is used to indication repetition (one or more terms)
-- See also regexp(1) man page on Unix systems for further details
-- A second kind of regular expressions is provided. This one is more
-- like the wild card patterns used in file names by the Unix shell (or
-- DOS prompt) command lines. The grammar is the following:
-- regexp ::= term
-- term ::= elmt
-- term ::= elmt elmt ... -- concatenation (elmt then elmt)
-- term ::= * -- any string of 0 or more characters
-- term ::= ? -- matches any character
-- term ::= [char char ...] -- matches any character listed
-- term ::= [char - char] -- matches any character in given range
-- term ::= {elmt, elmt, ...} -- alternation (matches any of elmt)
-- Important note : This package was mainly intended to match regular
-- expressions against file names. The whole string has to match the
-- regular expression. If only a substring matches, then the function
-- Match will return False.
type Regexp is private;
-- Private type used to represent a regular expression
Error_In_Regexp : exception;
-- Exception raised when an error is found in the regular expression
function Compile
(Pattern : String;
Glob : Boolean := False;
Case_Sensitive : Boolean := True)
return Regexp;
-- Compiles a regular expression S. If the syntax of the given
-- expression is invalid (does not match above grammar, Error_In_Regexp
-- is raised. If Glob is True, the pattern is considered as a 'globbing
-- pattern', that is a pattern as given by the second grammar above.
-- As a special case, if Pattern is the empty string it will always
-- match.
function Match (S : String; R : Regexp) return Boolean;
-- True if S matches R, otherwise False. Raises Constraint_Error if
-- R is an uninitialized regular expression value.
private
type Regexp_Value;
type Regexp_Access is access Regexp_Value;
type Regexp is new Ada.Finalization.Controlled with record
R : Regexp_Access := null;
end record;
pragma Finalize_Storage_Only (Regexp);
procedure Finalize (R : in out Regexp);
-- Free the memory occupied by R
procedure Adjust (R : in out Regexp);
-- Called after an assignment (do a copy of the Regexp_Access.all)
end GNAT.Regexp;
|
