g9ks157k at acme.softbase.org
Thu Oct 6 13:51:15 CEST 2011
Am Freitag, den 30.09.2011, 19:28 +0200 schrieb George Giorgidze:
> Basically the idea is to treat list literals like:
> fromList [1,2,3]
> class IsList l where
> type Item l
> fromList :: [Item l] -> l
Could we *please* not have classes whose names start with “Is”? We don’t
have classes IsNum, IsEq, or IsOrd, so why should we have IsList and
I know that the identifier String is already taken, but please don’t tie
an identifier like IsString or IsList to a language feature, so that
it’ll be difficult to change it later. Let’s search for a better
> In the following I give useful instances of the IsList class.
> instance (Ord a) => IsList (Set a) where
> type Item (Set a) = a
> fromList = Set.fromList
As a set is definitely not a list, the class should better be named
differently anyway, shouldn’t it?
Don’t know if these issues have already been pointed out, since I didn’t
read through the complete thread. Sorry, if they have already.
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