> So from this viewpoint (and regarding that example with squares), it's good
> to have also `Array.seq(from, to)` method (the name is taken from Erlang, I
> just frequently uses lists:seq(from, to) there):
<bikeshed>Array.range seems like an intuitive name as well.</bikeshed>
> Array.seq(1, 5).map((x) -> x * x); [1, 4, 9, 16, 25]
This pattern (integer range immediately followed by map) is so common that many
Schemes have a more general function that fuses the two traversals, sometimes
called build-list or list-tabulate:
Array.build(n, f) ~~~ [f(0), ..., f(n-1)]
Another common and useful fusion of two traversals that's in many Schemes is
map-filter or filter-map:
a.filterMap(f) ~~~ [res for [i,x] of items(a) let (res = f(x, i)) if (res
!== void 0)]
I rather arbitrarily chose to accept both null and undefined here as way to say
"no element" -- a reasonable alternative would be to accept *only* undefined as
"no element".
Dave
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