[no subject]

X = trunk.branch.leaf

If “leaf” is nil, “X” will be set to nil, but if “branch” or “trunk” is nil, this is an error “attempt to index a nil value”. Surely it would be architecturally more consistent (and practically more useful) if an attempt to index a nil value evaluated to nil?

From a recent piece of code I’ve written:

a = tb[p1]; if not a then return end

a = a[p2]; if not a then return end

a = a[p3]; if not a then return end

a = a[p4]; if not a then return end

It would have been neat to be able just to write:

a = tb[p1][p2][p3][p4]

if not a then return end

- John Hind