lib/sass/script/unary_operation.rb
module Sass::Script # A SassScript parse node representing a unary operation, # such as `-!b` or `not true`. # # Currently only `-`, `/`, and `not` are unary operators. class UnaryOperation < Node # @param operand [Script::Node] The parse-tree node # for the object of the operator # @param operator [Symbol] The operator to perform def initialize(operand, operator) @operand = operand @operator = operator end # @return [String] A human-readable s-expression representation of the operation def inspect "(#{@operator.inspect} #{@operand.inspect})" end # Evaluates the operation. # # @param environment [Sass::Environment] The environment in which to evaluate the SassScript # @return [Literal] The SassScript object that is the value of the operation # @raise [Sass::SyntaxError] if the operation is undefined for the operand def perform(environment) operator = "unary_#{@operator}" literal = @operand.perform(environment) literal.send(operator) rescue NoMethodError => e raise e unless e.name.to_s == operator.to_s raise Sass::SyntaxError.new("Undefined unary operation: \"#{@operator} #{literal}\".") end end end