1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S Y S T E M . R E G E X P -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1998-2010, AdaCore -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- Simple Regular expression matching 33 34-- This package provides a simple implementation of a regular expression 35-- pattern matching algorithm, using a subset of the syntax of regular 36-- expressions copied from familiar Unix style utilities. 37 38-- Note: this package is in the System hierarchy so that it can be directly 39-- be used by other predefined packages. User access to this package is via 40-- a renaming of this package in GNAT.Regexp (file g-regexp.ads). 41 42with Ada.Finalization; 43 44package System.Regexp is 45 46 -- The regular expression must first be compiled, using the Compile 47 -- function, which creates a finite state matching table, allowing 48 -- very fast matching once the expression has been compiled. 49 50 -- The following is the form of a regular expression, expressed in Ada 51 -- reference manual style BNF is as follows 52 53 -- regexp ::= term 54 55 -- regexp ::= term | term -- alternation (term or term ...) 56 57 -- term ::= item 58 59 -- term ::= item item ... -- concatenation (item then item) 60 61 -- item ::= elmt -- match elmt 62 -- item ::= elmt * -- zero or more elmt's 63 -- item ::= elmt + -- one or more elmt's 64 -- item ::= elmt ? -- matches elmt or nothing 65 66 -- elmt ::= nchr -- matches given character 67 -- elmt ::= [nchr nchr ...] -- matches any character listed 68 -- elmt ::= [^ nchr nchr ...] -- matches any character not listed 69 -- elmt ::= [char - char] -- matches chars in given range 70 -- elmt ::= . -- matches any single character 71 -- elmt ::= ( regexp ) -- parens used for grouping 72 73 -- char ::= any character, including special characters 74 -- nchr ::= any character except \()[].*+?^ or \char to match char 75 -- ... is used to indication repetition (one or more terms) 76 77 -- See also regexp(1) man page on Unix systems for further details 78 79 -- A second kind of regular expressions is provided. This one is more 80 -- like the wild card patterns used in file names by the Unix shell (or 81 -- DOS prompt) command lines. The grammar is the following: 82 83 -- regexp ::= term 84 85 -- term ::= elmt 86 87 -- term ::= elmt elmt ... -- concatenation (elmt then elmt) 88 -- term ::= * -- any string of 0 or more characters 89 -- term ::= ? -- matches any character 90 -- term ::= [char char ...] -- matches any character listed 91 -- term ::= [char - char] -- matches any character in given range 92 -- term ::= {elmt, elmt, ...} -- alternation (matches any of elmt) 93 94 -- Important note : This package was mainly intended to match regular 95 -- expressions against file names. The whole string has to match the 96 -- regular expression. If only a substring matches, then the function 97 -- Match will return False. 98 99 type Regexp is private; 100 -- Private type used to represent a regular expression 101 102 Error_In_Regexp : exception; 103 -- Exception raised when an error is found in the regular expression 104 105 function Compile 106 (Pattern : String; 107 Glob : Boolean := False; 108 Case_Sensitive : Boolean := True) return Regexp; 109 -- Compiles a regular expression S. If the syntax of the given 110 -- expression is invalid (does not match above grammar), Error_In_Regexp 111 -- is raised. If Glob is True, the pattern is considered as a 'globbing 112 -- pattern', that is a pattern as given by the second grammar above. 113 -- As a special case, if Pattern is the empty string it will always 114 -- match. 115 116 function Match (S : String; R : Regexp) return Boolean; 117 -- True if S matches R, otherwise False. Raises Constraint_Error if 118 -- R is an uninitialized regular expression value. 119 120private 121 type Regexp_Value; 122 123 type Regexp_Access is access Regexp_Value; 124 125 type Regexp is new Ada.Finalization.Controlled with record 126 R : Regexp_Access := null; 127 end record; 128 129 pragma Finalize_Storage_Only (Regexp); 130 131 procedure Finalize (R : in out Regexp); 132 -- Free the memory occupied by R 133 134 procedure Adjust (R : in out Regexp); 135 -- Called after an assignment (do a copy of the Regexp_Access.all) 136 137end System.Regexp; 138