APL's iota

So it's trivial to implement an APL-like iota combinator.

>> def iota = [ 0 -> 0 | N -> (iota (N-1)) N ]
>> iota 5
(0 1 2 3 4 5)

I subsequently set out to see if I could define factorial in an APL manner. The definition should be something like below.

>> def fac = mult @ map [X -> X + 1] @ iota

But the problem is Egel can't really pattern match readily against a variadic sized array. Take a variadic number of arguments, no problem; match against an n-adic construct, if n is known - sure; match against variadic array, no can do.

So, I either implement car/cdr like deconstruction combinators or I extend the pattern matching features. Where the new snag is that my bytecode doesn't support variadic pattern matching..