/**
* Consume the first work on the input tape
*
* @return The word of input
* @throws EmptyInputException
*/
public StackValue<?> consumeInput() throws EmptyInputException {
if (hasInput()) {
StackValue<?> value = input.get(inputIndex++);
for (StackMachineListener l : listeners) l.inputConsumed(inputIndex);
return value;
} else throw new EmptyInputException(programCounter);
}
