[Haskell-cafe] Better names for

Jon Fairbairn jon.fairbairn at cl.cam.ac.uk
Fri Apr 24 09:31:16 UTC 2020

Olaf Klinke <olf at aatal-apotheke.de> writes:

>> > fmap f. If I could re-define Haskell from scratch, I'd probably
>> >name
>> > the Functor type class function 'map'
>> As it was in Haskell 1.4
> That's interesting, I did not know this. Thanks for sharing. Are there
> any public records as to why the decision was made to re-name 'map' to
> 'fmap'? I can not find any mention in the Haskell98 report(s).

Sorry, I don’t know.

> There is a stackoverflow thread (#6824255) which mentions paedagogical
> reasons, simplifying error messages. 

That is the reason that I remember, the problem being that it
makes sense to teach map on lists before teaching type classes,
so error messages mentioning classes were considered confusing.

I was against this, preferring that teaching should use a
specialised prelude, but this was rejected on the grounds that
teachers wanted to teach “the real language”. I still think this
was a mistake.

  — Jón

Jón Fairbairn                                 Jon.Fairbairn at cl.cam.ac.uk

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