# File lib/sass/script/unary_operation.rb, line 48 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