gcc/ada/libgnat/a-slcain.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT LIBRARY COMPONENTS                          --
   4 --                                                                          --
   5 --                    ADA.STRINGS.LESS_CASE_INSENSITIVE                     --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2004-2017, 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
  30 with Ada.Characters.Handling; use Ada.Characters.Handling;
  31
  32 function Ada.Strings.Less_Case_Insensitive
  33   (Left, Right : String) return Boolean
  34 is
  35    LI : Integer := Left'First;
  36    RI : Integer := Right'First;
  37
  38    LC, RC : Character;
  39
  40 begin
  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;
  72 end Ada.Strings.Less_Case_Insensitive;