Type families and type inference - a question

Dmitry Tsygankov dmitry.tsygankov at gmail.com
Sun Jan 10 23:08:30 EST 2010


2010/1/10 Yitzchak Gale
> IMHO, the monomorphism restriction does not make sense at the
> GHCi prompt in any case, no matter what you have or haven't
> loaded, and no matter what your opinion of MR in general.
Looks reasonable to me, that's why I intuitively expected
let q = fmap MovieLister createFinder
to work.
Not sure I would want that behaviour when I ':load' a file though, as
it may provide a false sense of security. -XTypeFamilies isn't turned
on automatically, why should -XNoMonomorphismRestriction be?

> I recommend that you create a file called ".ghci"
> in your home directory, and put into it the line:
>
> :set -XNoMonomorphismRestriction
That seems to also affect how the file is ':load'-ed, not sure I would
want to do that.


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