function DOT(fnLeft, sIdentifier, aParts, oReference) {
		var oParent = fnLeft(aParts),
			vChild = oParent[sIdentifier];

		if (oReference) {
			oReference.base = oParent;
		}
		return clean(vChild);
	}
Formatter function for member access via the dot operator.
@param {function} fnLeft - formatter function for the left operand
@param {string} sIdentifier - the identifier on the dot's right side
@param {any[]} aParts - the array of binding values
@param {object} [oReference]
  optional side channel to return the base value (left operand) of the reference
@return {any} - the left operand's member with the name