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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . V A L _ C H A R --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2005, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
-- Boston, MA 02110-1301, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with System.Val_Util; use System.Val_Util;
package body System.Val_Char is
---------------------
-- Value_Character --
---------------------
function Value_Character (Str : String) return Character is
F : Natural;
L : Natural;
S : String (Str'Range) := Str;
begin
Normalize_String (S, F, L);
-- Accept any single character enclosed in quotes
if L - F = 2 and then S (F) = ''' and then S (L) = ''' then
return Character'Val (Character'Pos (S (F + 1)));
-- Check control character cases
else
for C in Character'Val (16#00#) .. Character'Val (16#1F#) loop
if S (F .. L) = Character'Image (C) then
return C;
end if;
end loop;
for C in Character'Val (16#7F#) .. Character'Val (16#9F#) loop
if S (F .. L) = Character'Image (C) then
return C;
end if;
end loop;
raise Constraint_Error;
end if;
end Value_Character;
end System.Val_Char;
|
