lib/arel/relations/selection.rb


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module Arel
  class Selection < Compound
    attr_reader :predicate

    def initialize(relation, *predicates)
      predicate = predicates.shift
      @relation = predicates.empty?? relation : Selection.new(relation, *predicates)
      @predicate = predicate.bind(@relation)
    end

    def selects
      @selects ||= (relation.selects + [predicate]).collect { |p| p.bind(self) }
    end    

    def ==(other)
      Selection  === other          and
      relation   ==  other.relation and
      predicate  ==  other.predicate
    end
  end
end