private WideningConversion(char type, Calculator calc, Primitive arg)
throws InvalidOperandException, InvalidTypeException {
super(type, calc);
// checks on parameters
if (arg == null) {
throw new InvalidOperandException("null operand in widening construction");
}
if (!Type.widens(type, arg.getType())) {
throw new InvalidTypeException("cannot widen type " + arg.getType() + " to type " + type);
}
this.arg = arg;
// calculates hashCode
final int prime = 281;
int result = 1;
result = prime * result + arg.hashCode();
result = prime * result + type;
this.hashCode = result;
// calculates toString
this.toString = "WIDEN-" + this.getType() + "(" + arg.toString() + ")";
}
