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------------------------------------------------------------------------------
-- --
-- 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 was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- 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;
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