whoward/cadenza

# frozen_string_literal: true

module Cadenza
  # The {BooleanInverseNode} takes an expression and evaluates the logical inverse
  # of that expression so any expression that evaluates to true will return false
  # and vice versa.
  class BooleanInverseNode
    include TreeNode

    # @return [OperationNode] an evaluatable expression node
    attr_accessor :expression

    # creates a new {BooleanInverseNode} with the given expression
    # @param [OperationNode] expression the node this one will invert
    def initialize(expression)
      @expression = expression
    end

    # @param [BooleanInverseNode] other
    # @return [Boolean] if the given {BooleanInverseNode} is equivalent by value
    def ==(other)
      @expression == other.expression
    end

    # evaluates the {#expression} and returns the inverted result
    # @param [Context] context
    # @return the value of this node evaluated with the data in the given {Context}
    def eval(context)
      # TODO: rename me to .evaluate
      !@expression.eval(context)
    end
  end
end