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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . R E G E X P --
-- --
-- S p e c --
-- --
-- Copyright (C) 1998-2024, AdaCore --
-- --
-- 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 3, 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. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- 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.
-- Note: this package is in the System hierarchy so that it can be directly
-- be used by other predefined packages. User access to this package is via
-- a renaming of this package in GNAT.Regexp (file g-regexp.ads).
with Ada.Finalization;
package System.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 wildcard patterns used in file names by the Unix shell (or
-- DOS prompt) command lines. The grammar is the following:
-- regexp ::= term
-- term ::= elmt
-- term ::= seq
-- term ::= {seq, seq, ...} -- alternation (matches any of seq)
-- seq ::= elmt elmt ... -- concatenation (sequence of elmts)
-- elmt ::= * -- any string of 0 or more characters
-- elmt ::= ? -- matches any character
-- elmt ::= char
-- elmt ::= [^ char char ...] -- matches any character not listed
-- elmt ::= [char char ...] -- matches any character listed
-- elmt ::= [char - char] -- matches any character in given range
-- \char is also supported by this grammar.
-- 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 System.Regexp;
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