1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT LIBRARY COMPONENTS                          --
4--                                                                          --
5--                    ADA.STRINGS.LESS_CASE_INSENSITIVE                     --
6--                                                                          --
7--                                 B o d y                                  --
8--                                                                          --
9--          Copyright (C) 2004-2009, Free Software Foundation, Inc.         --
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 3,  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.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 3.1, as published by the Free Software Foundation.               --
21--                                                                          --
22-- You should have received a copy of the GNU General Public License and    --
23-- a copy of the GCC Runtime Library Exception along with this program;     --
24-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
25-- <http://www.gnu.org/licenses/>.                                          --
26--                                                                          --
27-- This unit was originally developed by Matthew J Heaney.                  --
28------------------------------------------------------------------------------
29
30with Ada.Characters.Handling; use Ada.Characters.Handling;
31
32function Ada.Strings.Less_Case_Insensitive
33  (Left, Right : String) return Boolean
34is
35   LI : Integer := Left'First;
36   RI : Integer := Right'First;
37
38   LC, RC : Character;
39
40begin
41   if LI > Left'Last then
42      return RI <= Right'Last;
43   end if;
44
45   if RI > Right'Last then
46      return False;
47   end if;
48
49   loop
50      LC := To_Lower (Left (LI));
51      RC := To_Lower (Right (RI));
52
53      if LC < RC then
54         return True;
55      end if;
56
57      if LC > RC then
58         return False;
59      end if;
60
61      if LI = Left'Last then
62         return RI < Right'Last;
63      end if;
64
65      if RI = Right'Last then
66         return False;
67      end if;
68
69      LI := LI + 1;
70      RI := RI + 1;
71   end loop;
72end Ada.Strings.Less_Case_Insensitive;
73