private static void callFunction(SheepMachine vm, Stack <StackItem> stack, List <SheepImport> imports, int index, int numExpectedReturns)
{
int numParams = getInt(stack);
const int MAX_NUM_PARAMS = 16;
StackItem[] parms = new StackItem[MAX_NUM_PARAMS];
if (numParams >= MAX_NUM_PARAMS)
{
throw new Exception("More than the maximum number of allowed parameters found");
}
int numItemsOnStack = stack.Count;
// find the function
if (index < 0 || index >= imports.Count)
{
throw new Exception("Invalid import function");
}
if (imports[index].Parameters.Length != numParams)
{
throw new Exception("Invalid number of parameters to import function");
}
if (numParams > stack.Count)
{
throw new Exception("Stack is not in a valid state for calling this import function");
}
if (imports[index].Callback != null)
{
// TODO: call the callback
imports[index].Callback(vm);
}
int paramsLeftOver = numParams - (int)(numItemsOnStack - stack.Count);
if (paramsLeftOver > numExpectedReturns)
{
// lazy bums didn't pop everything off!
for (int i = numExpectedReturns; i < paramsLeftOver; i++)
{
stack.Pop();
}
}
else if (paramsLeftOver < numExpectedReturns)
{
// the idiots popped too much, or didn't put enough stuff on the stack!
throw new Exception("Incorrect number of items on the stack after function call");
}
}
private static void callIntFunction(SheepMachine vm, Stack <StackItem> stack, List <SheepImport> imports, int index)
{
callFunction(vm, stack, imports, index, 1);
}
private static void callVoidFunction(SheepMachine vm, Stack <StackItem> stack, List <SheepImport> imports, int index)
{
callFunction(vm, stack, imports, index, 0);
stack.Push(new StackItem(SheepSymbolType.Int, 0));
}