An approach for cheap small tables of int values

[Dibyendu Majumdar <mobile@...>]

One of the problems I have thought about for a while is how to
implement multi-dimensional array indexing efficiently. I have been
playing with Torch recently where I noticed that Lua tables are often
used as small sets of integer values representing tensor dimensions
etc.

I think it may be possible to have an optimized special case of small
table as follows:

If the table contains 1,2 or 3 int values, pack these into the TValue
itself - without any heap allocation. Then it will be quite cheap to
create these small table objects.

Of course this is just an initial thought and there are undoubtedly
implementation issues I have not foreseen.

Regards
Dibyendu