Num instance for functions
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== See also == | == See also == | ||
| + | * The [[applicative-numbers]] package, which generates numeric class instances for arbitrary [[applicative functor]]s (including functions). | ||
* http://www.haskell.org/pipermail/haskell-cafe/2006-November/019374.html | * http://www.haskell.org/pipermail/haskell-cafe/2006-November/019374.html | ||
* http://www.haskell.org/pipermail/haskell-cafe/2006-October/019105.html | * http://www.haskell.org/pipermail/haskell-cafe/2006-October/019105.html | ||
* http://www.haskell.org/pipermail/haskell-cafe/2001-February/001531.html | * http://www.haskell.org/pipermail/haskell-cafe/2001-February/001531.html | ||
| - | + | * http://augustss.blogspot.com/2009/02/regression-they-say-that-as-you-get.html | |
[[Category:Humor]] | [[Category:Humor]] | ||
[[Category:Proposals]] | [[Category:Proposals]] | ||
| - | [[ | + | [[Category:FAQ]] |
| + | [[Category:Style]] | ||
Current revision
Some people have argued, thatNum
(->)
to add functions nicely, say for
f, g :: Num a => b -> a
you would define
(f+g) x = f x + g x
fromInteger
fromInteger = const
numeric literals would also denote constant functions. This allows
f+2 == \x -> f x + 2
Even nicer, the mathematically established notation of omitting the multiplication dot
2(x+y) :: Integer
will now be parsed by a Haskell compiler to the most obvious meaning
2 :: Integer
! :-)
1 Note
This article is in category Proposals in order to show people that this idea was already proposed, but that one should think twice implementing it. There should be a category Counterproposals.
2 See also
- The applicative-numbers package, which generates numeric class instances for arbitrary applicative functors (including functions).
- http://www.haskell.org/pipermail/haskell-cafe/2006-November/019374.html
- http://www.haskell.org/pipermail/haskell-cafe/2006-October/019105.html
- http://www.haskell.org/pipermail/haskell-cafe/2001-February/001531.html
- http://augustss.blogspot.com/2009/02/regression-they-say-that-as-you-get.html
Categories: Humor | Proposals | FAQ | Style
