gcc/ada/s-regexp.ads

   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) 1998-2008, 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 2,  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.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  Simple Regular expression matching
  35
  36 --  This package provides a simple implementation of a regular expression
  37 --  pattern matching algorithm, using a subset of the syntax of regular
  38 --  expressions copied from familiar Unix style utilities.
  39
  40 --  Note: this package is in the System hierarchy so that it can be directly
  41 --  be used by other predefined packages. User access to this package is via
  42 --  a renaming of this package in GNAT.Regexp (file g-regexp.ads).
  43
  44 with Ada.Finalization;
  45
  46 package System.Regexp is
  47
  48    --  The regular expression must first be compiled, using the Compile
  49    --  function, which creates a finite state matching table, allowing
  50    --  very fast matching once the expression has been compiled.
  51
  52    --  The following is the form of a regular expression, expressed in Ada
  53    --  reference manual style BNF is as follows
  54
  55    --     regexp ::= term
  56
  57    --     regexp ::= term | term          -- alternation (term or term ...)
  58
  59    --     term ::= item
  60
  61    --     term ::= item item ...          -- concatenation (item then item)
  62
  63    --     item ::= elmt                   -- match elmt
  64    --     item ::= elmt *                 -- zero or more elmt's
  65    --     item ::= elmt +                 -- one or more elmt's
  66    --     item ::= elmt ?                 -- matches elmt or nothing
  67
  68    --     elmt ::= nchr                   -- matches given character
  69    --     elmt ::= [nchr nchr ...]        -- matches any character listed
  70    --     elmt ::= [^ nchr nchr ...]      -- matches any character not listed
  71    --     elmt ::= [char - char]          -- matches chars in given range
  72    --     elmt ::= .                      -- matches any single character
  73    --     elmt ::= ( regexp )             -- parens used for grouping
  74
  75    --     char ::= any character, including special characters
  76    --     nchr ::= any character except \()[].*+?^ or \char to match char
  77    --     ... is used to indication repetition (one or more terms)
  78
  79    --  See also regexp(1) man page on Unix systems for further details
  80
  81    --  A second kind of regular expressions is provided. This one is more
  82    --  like the wild card patterns used in file names by the Unix shell (or
  83    --  DOS prompt) command lines. The grammar is the following:
  84
  85    --     regexp ::= term
  86
  87    --     term   ::= elmt
  88
  89    --     term   ::= elmt elmt ...     -- concatenation (elmt then elmt)
  90    --     term   ::= *                 -- any string of 0 or more characters
  91    --     term   ::= ?                 -- matches any character
  92    --     term   ::= [char char ...]   -- matches any character listed
  93    --     term   ::= [char - char]     -- matches any character in given range
  94    --     term   ::= {elmt, elmt, ...} -- alternation (matches any of elmt)
  95
  96    --  Important note : This package was mainly intended to match regular
  97    --  expressions against file names. The whole string has to match the
  98    --  regular expression. If only a substring matches, then the function
  99    --  Match will return False.
 100
 101    type Regexp is private;
 102    --  Private type used to represent a regular expression
 103
 104    Error_In_Regexp : exception;
 105    --  Exception raised when an error is found in the regular expression
 106
 107    function Compile
 108      (Pattern        : String;
 109       Glob           : Boolean := False;
 110       Case_Sensitive : Boolean := True) return Regexp;
 111    --  Compiles a regular expression S. If the syntax of the given
 112    --  expression is invalid (does not match above grammar), Error_In_Regexp
 113    --  is raised. If Glob is True, the pattern is considered as a 'globbing
 114    --  pattern', that is a pattern as given by the second grammar above.
 115    --  As a special case, if Pattern is the empty string it will always
 116    --  match.
 117
 118    function Match (S : String; R : Regexp) return Boolean;
 119    --  True if S matches R, otherwise False. Raises Constraint_Error if
 120    --  R is an uninitialized regular expression value.
 121
 122 private
 123    type Regexp_Value;
 124
 125    type Regexp_Access is access Regexp_Value;
 126
 127    type Regexp is new Ada.Finalization.Controlled with record
 128       R : Regexp_Access := null;
 129    end record;
 130
 131    pragma Finalize_Storage_Only (Regexp);
 132
 133    procedure Finalize (R : in out Regexp);
 134    --  Free the memory occupied by R
 135
 136    procedure Adjust (R : in out Regexp);
 137    --  Called after an assignment (do a copy of the Regexp_Access.all)
 138
 139 end System.Regexp;