-- ----------------------------------------------------------------------------
--
--  Copyright (C) 2009 Stephe Leake
--  Copyright (C) 1999 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
-- ----------------------------------------------------------------------------

with Ada.Characters.Latin_1;
with Ada.Strings.Maps;
with Ada.Strings.Maps.Constants;

use type Ada.Strings.Maps.Character_Set;

-- --------------------------------------------------------------------------
--  This package implements a token recognizer for
--  comma-separated-value (CSV) fields of any type. Due to its general
--  nature, it should be declared later in the syntax than more
--  specific CSV field recognizers, so that it will work as a default
--  match. To facilitate that, it does not match any leading or
--  trailing whitespace.
-- --------------------------------------------------------------------------
package body OpenToken.Recognizer.CSV_Field is

   --  Characters that can be inside the field, but not at the ends
   Inner_Characters : constant Ada.Strings.Maps.Character_Set :=
     Ada.Strings.Maps.To_Set (Ada.Characters.Latin_1.HT &
                                Ada.Characters.Latin_1.Space);

   --  Characters that may appear anywhere in the field
   Match_Characters : constant Ada.Strings.Maps.Character_Set :=
     (Ada.Strings.Maps.Constants.Graphic_Set - Inner_Characters) -
     Ada.Strings.Maps.To_Set (',');

   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 => Match_Characters) 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 => Match_Characters) then
            Verdict := Matches;
         elsif Ada.Strings.Maps.Is_In (Element => Next_Char, Set => Inner_Characters) then
            Verdict := So_Far_So_Good;
         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 return Instance
   is begin
      return (Report => True, State  => First_Char);
   end Get;

end OpenToken.Recognizer.CSV_Field;