function UNARY(fnRight, fnOperator, aParts) {
		return fnOperator(fnRight(aParts));
	}
Formatter function for a unary operator.

@param {function} fnRight - formatter function for the operand
@param {function} fnOperator
  function to evaluate the unary operator taking one argument
@param {any[]} aParts - the array of binding values
@return {any} - the result of the operator function applied to the operand