private int PrepareFunctionCall(int position, ushort nbParams, Stack <double> valueStack, Stack <int> returnStack)
{
var functionNameHash = NanTags.DecodeVariableRef(valueStack.Pop());
var param = ReadParams(position, nbParams, valueStack);
// Evaluate function.
var evalResult = EvaluateFunctionCall(ref position, functionNameHash, nbParams, param, returnStack, valueStack);
// Add result on stack as a value.
if (NanTags.TypeOf(evalResult) != DataType.NoValue)
{
valueStack.Push(evalResult);
}
else if (NanTags.DecodeNonValue(evalResult) == NonValueType.Unit)
{
valueStack.Push(evalResult);
}
return(position);
}