private int ExecIndex(Instruction i, int instructionPtr)
{
int nestedMetaOps = 100; // sanity check, to avoid potential infinite loop here
// stack: base - index
DynValue idx = i.Value ?? m_ValueStack.Pop().ToScalar();
DynValue obj = m_ValueStack.Pop().ToScalar();
DynValue h = null;
while (nestedMetaOps > 0)
{
--nestedMetaOps;
if (obj.Type == DataType.Table)
{
var v = obj.Table.Get(idx);
if (!v.IsNil())
{
m_ValueStack.Push(v.AsReadOnly());
return(instructionPtr);
}
h = GetMetamethod(obj, "__index");
if (h == null || h.IsNil())
{
m_ValueStack.Push(DynValue.Nil);
return(instructionPtr);
}
}
else if (obj.Type == DataType.UserData)
{
UserData ud = obj.UserData;
var v = ud.Descriptor.Index(this.GetScript(), ud.Object, idx);
if (v == null)
{
throw ScriptRuntimeException.UserDataMissingField(ud.Descriptor.Name, idx.String);
}
m_ValueStack.Push(v.AsReadOnly());
return(instructionPtr);
}
else
{
h = GetMetamethod(obj, "__index");
if (h == null || h.IsNil())
{
throw ScriptRuntimeException.IndexType(obj);
}
}
if (h.Type == DataType.Function || h.Type == DataType.ClrFunction)
{
m_ValueStack.Push(h);
m_ValueStack.Push(obj);
m_ValueStack.Push(idx);
return(Internal_ExecCall(2, instructionPtr));
}
else
{
obj = h;
h = null;
}
}
throw ScriptRuntimeException.LoopInIndex();
}