# Simple Declarative Language (SDL) for Ruby
# Copyright 2005 Ikayzo, inc.
#
# This program is free software. You can distribute or modify it under the
# terms of the GNU Lesser General Public License version 2.1 as published by
# the Free Software Foundation.
#
# This program is distributed AS IS and WITHOUT WARRANTY. OF ANY KIND,
# INCLUDING MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
# See the GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, contact the Free Software Foundation, Inc.,
# 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.


module SDL4R
  
  require File.dirname(__FILE__) + '/parser'

  # An SDL token.
  #
  # @author Daniel Leuck, Philippe Vosges
  #
  class Token

    def initialize(text, line = -1, position = -1)
      @text = text
      @line = line
      @pos = position
      @size = text.length

      begin
        @type = nil
        @object = nil

        if text =~ /^["`]/
          @type = :STRING
          @object = Parser.parse_string(text)

        elsif text =~ /^'/
          @type = :CHARACTER
          @object = text[1...-1]

        elsif text == "null"
          @type = :NULL
          @object = nil

        elsif text =~ /^true$|^on$/
          @type = :BOOLEAN
          @object = true

        elsif text =~ /^false$|^off$/
          @type = :BOOLEAN
          @object = false

        elsif text =~ /^\[/
          @type=:BINARY
          @object = Parser.parse_binary(text)

        elsif text =~ /^\d+\/\d+\/\d+$/
          @type = :DATE;
          @object = Parser.parse_date_time(text)

        elsif text =~ /^-?\d+d?:\d+/
          @type = :TIME
          @object = parse_time_span_with_zone(text)

        elsif text =~ /^[\d\-\.]/
          @type = :NUMBER
          @object = Parser.parse_number(text)

        else
          case text[0]
          when ?{
            @type = :START_BLOCK
          when ?}
            @type = :END_BLOCK
          when ?=
            @type = :EQUALS
          when ?:
            @type = :COLON
          when ?;
            @type = :SEMICOLON
          end
        end

      rescue ArgumentError
        raise SdlParseError.new($!.message, @line, @pos)
      end

      @type = :IDENTIFIER if @type.nil? # if all hope is lost, it's an identifier

      @punctuation =
        @type == :COLON || @type == :SEMICOLON || @type == :EQUALS ||
        @type == :START_BLOCK || @type == :END_BLOCK
      @literal = @type != :IDENTIFIER && !@punctuation
    end

    attr_reader :text, :type, :line, :position

    def literal?
      @literal
    end

    # Returns the Ruby object corresponding to this literal (or nil if it is
    # not a literal).
    def object_for_literal
      return @object
    end

    def to_s
      @type.to_s + " " + @text + " pos:" + @pos.to_s
    end

    # This special parse method is used only by the Token class for
    # tokens which are ambiguously either a TimeSpan or the time component
    # of a date/time type
    def parse_time_span_with_zone(literal)
      raise ArgumentError("time span or date literal is nil") if literal.nil?

      days, hours, minutes, seconds, time_zone_offset =
        Parser.parse_time_span_and_time_zone(literal, true, true)

      return Parser::TimeSpanWithZone.new(days, hours, minutes, seconds, time_zone_offset)
    end
  end
  
end