Proposal: Num instance for (a -> b)

Anthony Clayden anthony_clayden at
Sat Nov 17 04:48:32 UTC 2018

> relevant reddit comment thread: ...

Are you people completely nuts? Haven't you wreaked enough havoc with
the Foldable Traversable Piffle?

Why ref pointy-headed discussion on reddit when you could also ref far
more frequent complaints:
"I think there must be something really wrong with the language design
here. I don't know exactly what it is, but I think someone must have
made the wrong tradeoff at some point."

(It's by no means only that author complaining; it's just that was
easiest to grab.)

No, EKmett, including `length` in `Foldable` with a `((,) a)` instance
is a lot more serious than "somewhat unfortunate".

> At what point is it better to put "weird" stuff into its own libraries (or newtypes) and keep base clean?

Always the standard Prelude should be clean of "weird" stuff. So that
beginners don't have to go round the houses to exclude the standard
and get a sensible Prelude. A beginner has more than enough to cope
with without piling the import mechanism on them.

Whereas it's no burden on the pointy-heads to import WeirdPrelude.

If the CLC process were to do anything useful, I'd expect yous to be
organising that. And then I could leave yew lot to turn your Haskell
into Perl, where any composition of symbols can acquire some meaning.

As it is, the only reason I monitor the Libraries list is to complain
about proposals for nuttiness.

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