[Haskell-cafe] Perl-style numeric type

Henning Thielemann lemming at henning-thielemann.de
Wed Jun 20 08:19:23 EDT 2007

On Wed, 20 Jun 2007, Brent Yorgey wrote:

> That's a good idea too, perhaps I will do that.  This would be a good thing
> to have on the wiki since it's clearly an issue that people learning Haskell
> struggle with (I certainly did).  I also want to make clear, though, that I
> certainly appreciate the reasons for strongly typed numbers.  I am not
> trying to make Haskell closer to Perl in general (God forbid!), or in any
> way advocate for doing away with strongly typed numbers, but only to create
> a library for working more conveniently with numeric types in small programs
> where the typing is not as important.  To give a couple quick examples,
> based on what I have already implemented:
> *EasyNum> 1 / 3
> 0.3333333333333333
> *EasyNum> 1 / 3 :: EasyNum
> 1/3
> *EasyNum> 1 / floor pi
> <interactive>:1:4:
>     Ambiguous type variable `t' in the constraints:
>       `Integral t' arising from use of `floor' at <interactive>:1:4-11
>       `Fractional t' arising from use of `/' at <interactive>:1:0-11
>     Probable fix: add a type signature that fixes these type variable(s)
> *EasyNum> 1 / floor pi :: EasyNum
> 1/3

How about
 1 % floor pi


Already two examples for the Wiki which I used to start the Wiki article:

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