Add a "last()" function that is like (len()-1)

[TomOnTime]

A major source of off-by-one errors for me is that with 0-based indexing there is no simple way to know the last element in an array. len(foo)-1 is convoluted.

Feature request: last(foo) should be the same as (len(foo)-1) thus making the intent very clear.

[vrok]

That's a good idea and I thing we should implement it.