/* Atoms do not hold variables.
* Makes for nice simplification by dereferencing variable names in
* the constructor and just dealing with integer values thereafter. */
private Atom(String token) {
/*
if (token == null || token.length() < 1)
throw new IllegalArgumentException(
"Tokens must have length > 1, but was '" + token + "'");
*/
if (token == null) throw new IllegalArgumentException("Tokens may not be null");
if (token.length() < 1) throw new IllegalArgumentException("Tokens may not be empty");
if (intPattern.matcher(token).matches()) {
val = Long.parseLong(token);
return;
}
if (token.length() == 1) {
op = MathOp.valueOf(token.charAt(0));
if (op != null) return;
}
// System.err.println("Trying '" + token + "'");
val = deref(token);
}
public static MathOp valueOf(char c) {
for (MathOp o : MathOp.values()) if (o.c == c) return o;
return null;
}
public String toString() {
return (op == null) ? Long.toString(val) : op.toString();
}