class Sass::Script::Operation

def _perform(environment)
  literal1 = @operand1.perform(environment)
  literal2 = @operand2.perform(environment)
  if @operator == :concat && context == :equals
    literal1 = Sass::Script::String.new(literal1.value) if literal1.is_a?(Sass::Script::String)
    literal2 = Sass::Script::String.new(literal2.value) if literal2.is_a?(Sass::Script::String)
  end
  begin
    res = literal1.send(@operator, literal2)
    res.options = environment.options
    res
  rescue NoMethodError => e
    raise e unless e.name.to_s == @operator.to_s
    raise Sass::SyntaxError.new("Undefined operation: \"#{literal1} #{@operator} #{literal2}\".")
  end
end

def children
  [@operand1, @operand2]
end

def initialize(operand1, operand2, operator)
  @operand1 = operand1
  @operand2 = operand2
  @operator = operator
  super()
end

def inspect
  "(#{@operator.inspect} #{@operand1.inspect} #{@operand2.inspect})"
end

def operand_to_sass(pred, op, opts = {})
  return "(#{op.to_sass(opts)})" if op.is_a?(Operation) &&
    Sass::Script::Parser.precedence_of(op.operator) < pred
  op.to_sass(opts)
end

def to_sass(opts = {})
  pred = Sass::Script::Parser.precedence_of(@operator)
  o1 = operand_to_sass pred, @operand1, opts
  o2 = operand_to_sass pred, @operand2, opts
  sep =
    case @operator
    when :comma; ", "
    when :concat; " "
    else; " #{Lexer::OPERATORS_REVERSE[@operator]} "
    end
  "#{o1}#{sep}#{o2}"
end