Proposal reminder: Add functions to get consecutive elements to Data.List

wren romano winterkoninkje at
Fri May 20 05:27:09 UTC 2016

On Thu, May 19, 2016 at 2:33 PM, Theodore Lief Gannon <tanuki at> wrote:
> Whoops, responded privately (and also made a mistake I wanted to correct, so
> I guess that works out). To the list this time:
> I don't like using the 'zip' terminology here; I feel like that should be
> reserved for multiple distinct data sources.
> Why not 'map2'?

I too dislike the "zip" terminology here, for the same reason. But I
also I mislike "map" since this isn't functorial in any particular way
(I'd expect "map2" to have to do with some sort of 2-functors).

I'm agnostic on adding the function vs not, but If we're bikeshedding
for short names how about "twine"? (The problem I see with "pairwise"
is that it's ambiguous about whether values get "reused": i.e.,
matching even elements to odds[1], vs matching every element to the

[1] I also note without comment that this interpretation is the
inverse to what is traditionally called "zip" in the non-wellfounded
set theory community; e.g., when viewing streams (like the Thue–Morse
sequence) as a greatest solution to a system of equations.

Live well,

More information about the Libraries mailing list