1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                      S Y S T E M . V A L _ C H A R                       --
6--                                                                          --
7--                                 B o d y                                  --
8--                                                                          --
9--          Copyright (C) 1992-2012, 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
32with System.Val_Util; use System.Val_Util;
33
34package body System.Val_Char is
35
36   ---------------------
37   -- Value_Character --
38   ---------------------
39
40   function Value_Character (Str : String) return Character is
41      F : Natural;
42      L : Natural;
43      S : String (Str'Range) := Str;
44
45   begin
46      Normalize_String (S, F, L);
47
48      --  Accept any single character enclosed in quotes
49
50      if L - F = 2 and then S (F) = ''' and then S (L) = ''' then
51         return Character'Val (Character'Pos (S (F + 1)));
52
53      --  Check control character cases
54
55      else
56         for C in Character'Val (16#00#) .. Character'Val (16#1F#) loop
57            if S (F .. L) = Character'Image (C) then
58               return C;
59            end if;
60         end loop;
61
62         for C in Character'Val (16#7F#) .. Character'Val (16#9F#) loop
63            if S (F .. L) = Character'Image (C) then
64               return C;
65            end if;
66         end loop;
67
68         if S (F .. L) = "SOFT_HYPHEN" then
69            return Character'Val (16#AD#);
70         end if;
71
72         Bad_Value (Str);
73      end if;
74   end Value_Character;
75
76end System.Val_Char;
77