-- ----------------------------------------------------------------------------
--
--  Copyright (C) 1999, 2012 FlightSafety International and Ted Dennison
--
--  This file is part of the OpenToken package.
--
--  The OpenToken package is free software; you can redistribute it and/or
--  modify it under the terms of the  GNU General Public License as published
--  by the Free Software Foundation; either version 3, or (at your option)
--  any later version. The OpenToken package is distributed in the hope that
--  it will be useful, but WITHOUT 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 the OpenToken
--  package;  see file GPL.txt.  If not, write to  the Free Software Foundation,
--  59 Temple Place - Suite 330,  Boston, MA 02111-1307, 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.
--
--  This software was originally developed by the following company,
--  and was released as open-source software as a service to the
--  community:
--
--           FlightSafety International Simulation Systems Division
--                    Broken Arrow, OK  USA  918-259-4000
--
-- ----------------------------------------------------------------------------

-- ----------------------------------------------------------------------------
--  This package implements a token recognizer for an identifier
-- ----------------------------------------------------------------------------
package body OpenToken.Recognizer.Identifier is

   overriding procedure Clear (The_Token : in out Instance)
   is begin
      The_Token.State := First_Char;
   end Clear;

   overriding procedure Analyze
     (The_Token : in out Instance;
      Next_Char : in     Character;
      Verdict   :    out Analysis_Verdict)
   is begin

      case The_Token.State is

      when First_Char =>
         if Ada.Strings.Maps.Is_In
           (Element => Next_Char,
            Set     => The_Token.Start_Chars)
         then
            Verdict         := Matches;
            The_Token.State := Text;
         else
            Verdict         := Failed;
            The_Token.State := Done;
         end if;

      when Text =>
         if
           Ada.Strings.Maps.Is_In
           (Element => Next_Char,
            Set     => The_Token.Body_Chars)
         then
            Verdict := Matches;
         elsif Next_Char = '_' and then The_Token.Has_Separator then
            Verdict         := So_Far_So_Good;
            The_Token.State := Underscore;
         else
            Verdict         := Failed;
            The_Token.State := Done;
         end if;

      when Underscore =>
         if
           Ada.Strings.Maps.Is_In
           (Element => Next_Char,
            Set     => The_Token.Body_Chars)
         then
            Verdict         := Matches;
            The_Token.State := Text;
         else
            Verdict         := Failed;
            The_Token.State := Done;
         end if;

      when Done =>
         --  We shouldn't get called from here.
         Verdict := Failed;

      end case;

   end Analyze;

   function Get
     (Start_Chars   : in Ada.Strings.Maps.Character_Set;
      Body_Chars    : in Ada.Strings.Maps.Character_Set;
      Has_Separator : in Boolean := True)
     return Instance
   is begin
      return (Report        => True,
              Start_Chars   => Start_Chars,
              Body_Chars    => Body_Chars,
              Has_Separator => Has_Separator,
              State         => First_Char);
   end Get;

end OpenToken.Recognizer.Identifier;