/**
* Executes the current instruction (Program at pc). Returns false if END command, true otherwise.
*/
public void executeInstruction() throws ProgramException {
currentInstruction = program.getNextInstruction();
if (currentInstruction == null) throw new ProgramException("No more instructions to execute");
switch (currentInstruction.getOpCode()) {
case HVMInstructionSet.ADD_CODE:
add();
break;
case HVMInstructionSet.SUBSTRACT_CODE:
substract();
break;
case HVMInstructionSet.NEGATE_CODE:
negate();
break;
case HVMInstructionSet.EQUAL_CODE:
equal();
break;
case HVMInstructionSet.GREATER_THAN_CODE:
greaterThan();
break;
case HVMInstructionSet.LESS_THAN_CODE:
lessThan();
break;
case HVMInstructionSet.AND_CODE:
and();
break;
case HVMInstructionSet.OR_CODE:
or();
break;
case HVMInstructionSet.NOT_CODE:
not();
break;
case HVMInstructionSet.PUSH_CODE:
push(currentInstruction.getArg0(), currentInstruction.getArg1());
break;
case HVMInstructionSet.POP_CODE:
pop(currentInstruction.getArg0(), currentInstruction.getArg1());
break;
case HVMInstructionSet.GOTO_CODE:
goTo(currentInstruction.getArg0());
break;
case HVMInstructionSet.IF_GOTO_CODE:
ifGoTo(currentInstruction.getArg0());
break;
case HVMInstructionSet.FUNCTION_CODE:
if (program.getCurrentPC() == program.getPreviousPC() + 1)
throw new ProgramException("Missing return in " + callStack.getTopFunction());
function(currentInstruction.getArg0());
break;
case HVMInstructionSet.RETURN_CODE:
returnFromFunction();
break;
case HVMInstructionSet.CALL_CODE:
callFunction(
currentInstruction.getArg0(),
currentInstruction.getArg1(),
currentInstruction.getStringArg(),
false);
break;
}
}
