Re: Standard Libraries: (was: and Lua marches on)

[steve donovan <steve.j.donovan@...>]

On Thu, Dec 17, 2009 at 3:43 PM, Tony Finch <dot@dotat.at> wrote:
> Traditional functional libraries don't have a map2() function since
> it can be trivially defined as something like:
>
>        function map2(f,xs,ys)
>                return map(f,zip(xs,ys))
>        end
>

That makes sense, so really it's zip that's the important one here. We
don't really have tuples so zip({1,2,3},{10,20,30}) would give
{{1,10},{2,20},{3,30}}, so the actual function passed to map() here
would be the composition of f and unpack.

What do you think about going beyond ordered lists, given that we are
likely to want to operate on hashes as well?  A useful standard
transform is {a=1,b=2} => {{'a',1},{'b',2}} so it's always possible to
reduce hashes to lists.

steve d.