package calculator; /** * Enumeration of the 3 ways to represent an arithmetic expression as a String: */ public enum Notation { /** * Prefix notation, e.g. "+(1,2)" or "+ 1 2" */ PREFIX, /** * Infix notation, e.g. "1+2" */ INFIX, /** * Postfix notation, e.g. "(1,2)+" or "1 2 +" */ POSTFIX }