------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- A D A . S T R I N G S . S E A R C H --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2009, 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 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 --
-- . --
-- --
-- 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;
with System; use System;
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
PL1 : constant Integer := Pattern'Length - 1;
Num : Natural;
Ind : Natural;
Cur : Natural;
begin
if Pattern = "" then
raise Pattern_Error;
end if;
Num := 0;
Ind := Source'First;
-- Unmapped case
if Mapping'Address = Maps.Identity'Address then
while Ind <= Source'Last - PL1 loop
if Pattern = Source (Ind .. Ind + PL1) then
Num := Num + 1;
Ind := Ind + Pattern'Length;
else
Ind := Ind + 1;
end if;
end loop;
-- Mapped case
else
while Ind <= Source'Last - PL1 loop
Cur := Ind;
for K in Pattern'Range loop
if Pattern (K) /= Value (Mapping, Source (Cur)) then
Ind := Ind + 1;
goto Cont;
else
Cur := Cur + 1;
end if;
end loop;
Num := Num + 1;
Ind := Ind + Pattern'Length;
<>
null;
end loop;
end if;
-- Return result
return Num;
end Count;
function Count
(Source : String;
Pattern : String;
Mapping : Maps.Character_Mapping_Function) return Natural
is
PL1 : constant Integer := Pattern'Length - 1;
Num : Natural;
Ind : Natural;
Cur : Natural;
begin
if Pattern = "" then
raise Pattern_Error;
end if;
-- Check for null pointer in case checks are off
if Mapping = null then
raise Constraint_Error;
end if;
Num := 0;
Ind := Source'First;
while Ind <= Source'Last - PL1 loop
Cur := Ind;
for K in Pattern'Range loop
if Pattern (K) /= Mapping (Source (Cur)) then
Ind := Ind + 1;
goto Cont;
else
Cur := Cur + 1;
end if;
end loop;
Num := Num + 1;
Ind := Ind + Pattern'Length;
<>
null;
end loop;
return Num;
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 first 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
PL1 : constant Integer := Pattern'Length - 1;
Cur : Natural;
Ind : Integer;
-- Index for start of match check. This can be negative if the pattern
-- length is greater than the string length, which is why this variable
-- is Integer instead of Natural. In this case, the search loops do not
-- execute at all, so this Ind value is never used.
begin
if Pattern = "" then
raise Pattern_Error;
end if;
-- Forwards case
if Going = Forward then
Ind := Source'First;
-- Unmapped forward case
if Mapping'Address = Maps.Identity'Address then
for J in 1 .. Source'Length - PL1 loop
if Pattern = Source (Ind .. Ind + PL1) then
return Ind;
else
Ind := Ind + 1;
end if;
end loop;
-- Mapped forward case
else
for J in 1 .. Source'Length - PL1 loop
Cur := Ind;
for K in Pattern'Range loop
if Pattern (K) /= Value (Mapping, Source (Cur)) then
goto Cont1;
else
Cur := Cur + 1;
end if;
end loop;
return Ind;
<>
Ind := Ind + 1;
end loop;
end if;
-- Backwards case
else
-- Unmapped backward case
Ind := Source'Last - PL1;
if Mapping'Address = Maps.Identity'Address then
for J in reverse 1 .. Source'Length - PL1 loop
if Pattern = Source (Ind .. Ind + PL1) then
return Ind;
else
Ind := Ind - 1;
end if;
end loop;
-- Mapped backward case
else
for J in reverse 1 .. Source'Length - PL1 loop
Cur := Ind;
for K in Pattern'Range loop
if Pattern (K) /= Value (Mapping, Source (Cur)) then
goto Cont2;
else
Cur := Cur + 1;
end if;
end loop;
return Ind;
<>
Ind := Ind - 1;
end loop;
end if;
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
PL1 : constant Integer := Pattern'Length - 1;
Ind : Natural;
Cur : Natural;
begin
if Pattern = "" then
raise Pattern_Error;
end if;
-- Check for null pointer in case checks are off
if Mapping = null then
raise Constraint_Error;
end if;
-- If Pattern longer than Source it can't be found
if Pattern'Length > Source'Length then
return 0;
end if;
-- Forwards case
if Going = Forward then
Ind := Source'First;
for J in 1 .. Source'Length - PL1 loop
Cur := Ind;
for K in Pattern'Range loop
if Pattern (K) /= Mapping.all (Source (Cur)) then
goto Cont1;
else
Cur := Cur + 1;
end if;
end loop;
return Ind;
<>
Ind := Ind + 1;
end loop;
-- Backwards case
else
Ind := Source'Last - PL1;
for J in reverse 1 .. Source'Length - PL1 loop
Cur := Ind;
for K in Pattern'Range loop
if Pattern (K) /= Mapping.all (Source (Cur)) then
goto Cont2;
else
Cur := Cur + 1;
end if;
end loop;
return Ind;
<>
Ind := Ind - 1;
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;
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;
function Index
(Source : String;
Pattern : String;
From : Positive;
Going : Direction := Forward;
Mapping : Maps.Character_Mapping := Maps.Identity) return Natural
is
begin
if Going = Forward then
if From < Source'First then
raise Index_Error;
end if;
return
Index (Source (From .. Source'Last), Pattern, Forward, Mapping);
else
if From > Source'Last then
raise Index_Error;
end if;
return
Index (Source (Source'First .. From), Pattern, Backward, Mapping);
end if;
end Index;
function Index
(Source : String;
Pattern : String;
From : Positive;
Going : Direction := Forward;
Mapping : Maps.Character_Mapping_Function) return Natural
is
begin
if Going = Forward then
if From < Source'First then
raise Index_Error;
end if;
return Index
(Source (From .. Source'Last), Pattern, Forward, Mapping);
else
if From > Source'Last then
raise Index_Error;
end if;
return Index
(Source (Source'First .. From), Pattern, Backward, Mapping);
end if;
end Index;
function Index
(Source : String;
Set : Maps.Character_Set;
From : Positive;
Test : Membership := Inside;
Going : Direction := Forward) return Natural
is
begin
if Going = Forward then
if From < Source'First then
raise Index_Error;
end if;
return
Index (Source (From .. Source'Last), Set, Test, Forward);
else
if From > Source'Last then
raise Index_Error;
end if;
return
Index (Source (Source'First .. From), Set, Test, Backward);
end if;
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;
function Index_Non_Blank
(Source : String;
From : Positive;
Going : Direction := Forward) return Natural
is
begin
if Going = Forward then
if From < Source'First then
raise Index_Error;
end if;
return
Index_Non_Blank (Source (From .. Source'Last), Forward);
else
if From > Source'Last then
raise Index_Error;
end if;
return
Index_Non_Blank (Source (Source'First .. From), Backward);
end if;
end Index_Non_Blank;
end Ada.Strings.Search;