#
# iset.rb
#
# Copyright (c) 1999-2003 Minero Aoki <aamine@loveruby.net>
#
# This program is free software.
# You can distribute/modify this program under the terms of
# the GNU LGPL, Lesser General Public License version 2.
# For details of the GNU LGPL, see the file "COPYING".
#

module Racc

  #
  # ISet
  #
  # indexed set.
  # all items must respond to :ident
  #

  class ISet

    def initialize( a = [] )
      @set = a
    end

    attr_reader :set

    def add( i )
      @set[i.ident] = i
    end

    def []( key )
      @set[key.ident]
    end

    def []=( key, val )
      @set[key.ident] = val
    end

    alias include? []
    alias key? []

    def update( other )
      s = @set
      o = other.set
      o.each_index do |idx|
        if t = o[idx]
          s[idx] = t
        end
      end
    end

    def update_a( a )
      s = @set
      i = nil
      a.each {|i| s[i.ident] = i }
    end

    def delete( key )
      i = @set[key.ident]
      @set[key.ident] = nil
      i
    end

    def each( &block )
      @set.compact.each(&block)
    end

    def to_a
      @set.compact
    end

    def to_s
      "[#{@set.compact.join(' ')}]"
    end

    alias inspect to_s

    def size
      @set.nitems
    end

    def empty?
      @set.nitems == 0
    end

    def clear
      @set.clear
    end

    def dup
      ISet.new(@set.dup)
    end
  
  end   # class ISet

end   # module Racc
