1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . V A L _ W C H A R --
9 -- Copyright (C) 1992-2005, Free Software Foundation, Inc. --
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 2, 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. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 with Interfaces; use Interfaces;
35 with System.Val_Util; use System.Val_Util;
36 with System.WCh_Con; use System.WCh_Con;
37 with System.WCh_StW; use System.WCh_StW;
39 package body System.Val_WChar is
41 --------------------------
42 -- Value_Wide_Character --
43 --------------------------
45 function Value_Wide_Character
47 EM : WC_Encoding_Method) return Wide_Character
49 WWC : constant Wide_Wide_Character :=
50 Value_Wide_Wide_Character (Str, EM);
51 WWV : constant Unsigned_32 := Wide_Wide_Character'Pos (WWC);
53 if WWV > 16#FFFF# then
54 raise Constraint_Error;
56 return Wide_Character'Val (WWV);
58 end Value_Wide_Character;
60 -------------------------------
61 -- Value_Wide_Wide_Character --
62 -------------------------------
64 function Value_Wide_Wide_Character
66 EM : System.WCh_Con.WC_Encoding_Method) return Wide_Wide_Character
70 S : String (Str'Range) := Str;
73 Normalize_String (S, F, L);
75 -- Character literal case
77 if S (F) = ''' and then S (L) = ''' then
79 -- If just three characters, simple character case
82 return Wide_Wide_Character'Val (Character'Pos (S (F + 1)));
84 -- Otherwise must be a wide character in quotes. The easiest
85 -- thing is to convert the string to a wide wide string and then
86 -- pick up the single character that it should contain.
90 WS : constant Wide_Wide_String :=
91 String_To_Wide_Wide_String (S (F + 1 .. L - 1), EM);
94 if WS'Length /= 1 then
95 raise Constraint_Error;
102 -- the last two values of the type have language-defined names:
104 elsif S = "FFFE" then
105 return Wide_Wide_Character'Val (16#FFFE#);
107 elsif S = "FFFF" then
108 return Wide_Wide_Character'Val (16#FFFF#);
110 -- Otherwise must be a control character
113 for C in Character'Val (16#00#) .. Character'Val (16#1F#) loop
114 if S (F .. L) = Character'Image (C) then
115 return Wide_Wide_Character'Val (Character'Pos (C));
119 for C in Character'Val (16#7F#) .. Character'Val (16#9F#) loop
120 if S (F .. L) = Character'Image (C) then
121 return Wide_Wide_Character'Val (Character'Pos (C));
125 raise Constraint_Error;
127 end Value_Wide_Wide_Character;
129 end System.Val_WChar;