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------------------------------------------------------------------------------
-- --
-- GNAT RUNTIME COMPONENTS --
-- --
-- A D A . S T R I N G S . S E A R C H --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2004 Free Software Foundation, 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. --
-- --
------------------------------------------------------------------------------
-- Note: This code is derived from the ADAR.CSH public domain Ada 83
-- versions of the Appendix C string handling packages (code extracted
-- from Ada.Strings.Fixed). A significant change is that we optimize the
-- case of identity mappings for Count and Index, and also Index_Non_Blank
-- is specialized (rather than using the general Index routine).
with Ada.Strings.Maps; use Ada.Strings.Maps;
package body Ada.Strings.Search is
-----------------------
-- Local Subprograms --
-----------------------
function Belongs
(Element : Character;
Set : Maps.Character_Set;
Test : Membership) return Boolean;
pragma Inline (Belongs);
-- Determines if the given element is in (Test = Inside) or not in
-- (Test = Outside) the given character set.
-------------
-- Belongs --
-------------
function Belongs
(Element : Character;
Set : Maps.Character_Set;
Test : Membership) return Boolean
is
begin
if Test = Inside then
return Is_In (Element, Set);
else
return not Is_In (Element, Set);
end if;
end Belongs;
-----------
-- Count --
-----------
function Count
(Source : String;
Pattern : String;
Mapping : Maps.Character_Mapping := Maps.Identity) return Natural
is
N : Natural;
J : Natural;
Mapped_Source : String (Source'Range);
begin
for J in Source'Range loop
Mapped_Source (J) := Value (Mapping, Source (J));
end loop;
if Pattern = "" then
raise Pattern_Error;
end if;
N := 0;
J := Source'First;
while J <= Source'Last - (Pattern'Length - 1) loop
if Mapped_Source (J .. J + (Pattern'Length - 1)) = Pattern then
N := N + 1;
J := J + Pattern'Length;
else
J := J + 1;
end if;
end loop;
return N;
end Count;
function Count
(Source : String;
Pattern : String;
Mapping : Maps.Character_Mapping_Function) return Natural
is
Mapped_Source : String (Source'Range);
N : Natural;
J : Natural;
begin
if Pattern = "" then
raise Pattern_Error;
end if;
-- We make sure Access_Check is unsuppressed so that the Mapping.all
-- call will generate a friendly Constraint_Error if the value for
-- Mapping is uninitialized (and hence null).
declare
pragma Unsuppress (Access_Check);
begin
for J in Source'Range loop
Mapped_Source (J) := Mapping.all (Source (J));
end loop;
end;
N := 0;
J := Source'First;
while J <= Source'Last - (Pattern'Length - 1) loop
if Mapped_Source (J .. J + (Pattern'Length - 1)) = Pattern then
N := N + 1;
J := J + Pattern'Length;
else
J := J + 1;
end if;
end loop;
return N;
end Count;
function Count
(Source : String;
Set : Maps.Character_Set) return Natural
is
N : Natural := 0;
begin
for J in Source'Range loop
if Is_In (Source (J), Set) then
N := N + 1;
end if;
end loop;
return N;
end Count;
----------------
-- Find_Token --
----------------
procedure Find_Token
(Source : String;
Set : Maps.Character_Set;
Test : Membership;
First : out Positive;
Last : out Natural)
is
begin
for J in Source'Range loop
if Belongs (Source (J), Set, Test) then
First := J;
for K in J + 1 .. Source'Last loop
if not Belongs (Source (K), Set, Test) then
Last := K - 1;
return;
end if;
end loop;
-- Here if J indexes 1st char of token, and all chars
-- after J are in the token
Last := Source'Last;
return;
end if;
end loop;
-- Here if no token found
First := Source'First;
Last := 0;
end Find_Token;
-----------
-- Index --
-----------
function Index
(Source : String;
Pattern : String;
Going : Direction := Forward;
Mapping : Maps.Character_Mapping := Maps.Identity) return Natural
is
Cur_Index : Natural;
Mapped_Source : String (Source'Range);
begin
if Pattern = "" then
raise Pattern_Error;
end if;
for J in Source'Range loop
Mapped_Source (J) := Value (Mapping, Source (J));
end loop;
-- Forwards case
if Going = Forward then
for J in 1 .. Source'Length - Pattern'Length + 1 loop
Cur_Index := Source'First + J - 1;
if Pattern = Mapped_Source
(Cur_Index .. Cur_Index + Pattern'Length - 1)
then
return Cur_Index;
end if;
end loop;
-- Backwards case
else
for J in reverse 1 .. Source'Length - Pattern'Length + 1 loop
Cur_Index := Source'First + J - 1;
if Pattern = Mapped_Source
(Cur_Index .. Cur_Index + Pattern'Length - 1)
then
return Cur_Index;
end if;
end loop;
end if;
-- Fall through if no match found. Note that the loops are skipped
-- completely in the case of the pattern being longer than the source.
return 0;
end Index;
function Index
(Source : String;
Pattern : String;
Going : Direction := Forward;
Mapping : Maps.Character_Mapping_Function) return Natural
is
Mapped_Source : String (Source'Range);
Cur_Index : Natural;
begin
if Pattern = "" then
raise Pattern_Error;
end if;
-- We make sure Access_Check is unsuppressed so that the Mapping.all
-- call will generate a friendly Constraint_Error if the value for
-- Mapping is uninitialized (and hence null).
declare
pragma Unsuppress (Access_Check);
begin
for J in Source'Range loop
Mapped_Source (J) := Mapping.all (Source (J));
end loop;
end;
-- Forwards case
if Going = Forward then
for J in 1 .. Source'Length - Pattern'Length + 1 loop
Cur_Index := Source'First + J - 1;
if Pattern = Mapped_Source
(Cur_Index .. Cur_Index + Pattern'Length - 1)
then
return Cur_Index;
end if;
end loop;
-- Backwards case
else
for J in reverse 1 .. Source'Length - Pattern'Length + 1 loop
Cur_Index := Source'First + J - 1;
if Pattern = Mapped_Source
(Cur_Index .. Cur_Index + Pattern'Length - 1)
then
return Cur_Index;
end if;
end loop;
end if;
return 0;
end Index;
function Index
(Source : String;
Set : Maps.Character_Set;
Test : Membership := Inside;
Going : Direction := Forward) return Natural
is
begin
-- Forwards case
if Going = Forward then
for J in Source'Range loop
if Belongs (Source (J), Set, Test) then
return J;
end if;
end loop;
-- Backwards case
else
for J in reverse Source'Range loop
if Belongs (Source (J), Set, Test) then
return J;
end if;
end loop;
end if;
-- Fall through if no match
return 0;
end Index;
---------------------
-- Index_Non_Blank --
---------------------
function Index_Non_Blank
(Source : String;
Going : Direction := Forward) return Natural
is
begin
if Going = Forward then
for J in Source'Range loop
if Source (J) /= ' ' then
return J;
end if;
end loop;
else -- Going = Backward
for J in reverse Source'Range loop
if Source (J) /= ' ' then
return J;
end if;
end loop;
end if;
-- Fall through if no match
return 0;
end Index_Non_Blank;
end Ada.Strings.Search;
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