gcc/ada/libgnat/s-valboo.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                      S Y S T E M . V A L _ B O O L                       --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2020, 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 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 with System.Val_Util; use System.Val_Util;
  33
  34 package body System.Val_Bool is
  35
  36    -------------------
  37    -- Value_Boolean --
  38    -------------------
  39
  40    function Value_Boolean (Str : String) return Boolean is
  41       F : Natural;
  42       L : Natural;
  43       S : String (Str'Range) := Str;
  44
  45    begin
  46       Normalize_String (S, F, L);
  47
  48       if S (F .. L) = "TRUE" then
  49          return True;
  50
  51       elsif S (F .. L) = "FALSE" then
  52          return False;
  53
  54       else
  55          Bad_Value (Str);
  56       end if;
  57    end Value_Boolean;
  58
  59 end System.Val_Bool;