Question

Potentially dumb:
Assuming I have a string containing an operator what’s the best way to apply this operator ?

What i tend to do is :

if(n.getString(1).equals("<<")) {
  result = tmp1 << tmp2;
}

for each kind of operator I have. Is there a better way ?

Answer 1

Could do something like:

enum Operator {

 BITSHIFT { ... }, ADD { ... }, XOR { ... }, //...etc

 Operator public static which(String s) { //...return the correct one
 }

 public abstract int apply(int a, int b); //...defined explicitly for each enum

}

the return the right one will be really nice once switch statements are go for Strings.

This solution looks like the following in use (sans Operator. if you use a static import):

 int result = Operator.which(s).apply(a,b);

but I’d go with someone else’s widely-tested and used parser.