Add ifThenElse and (?) to Data.Bool

[Ivan Lazar Miljenovic]

I'm -0.5 on ifThenElse (if it can be used with RebindableSyntax then
someone may want to use it, though I personally find the bool function
to be more than sufficient as I tend to find the "which branch do I
choose" argument to be the last when constructing function pipelines),
and -1 for the operator.

On 17 November 2016 at 13:43, winter <drkoster at qq.com> wrote:
> It seems this’s a very old request, see
> https://wiki.haskell.org/If-then-else. I’d like to see following:
>
>
> ifThenElse :: Bool -> a -> a -> a
> ifThenElse True  x _ = x
> ifThenElse False _ y = y
>
>
> infixr 1 ?
> (?) :: Bool -> a -> a -> a
> (?) = ifThenElse
>
>
> in Date.Bool module, it will have advantages that:
>
>
> + It’s more composable than syntax.
>
> + Write (xxx ? yyy $ zzz) instead of (if xxx then yyy else zzz) is more
> consistent with (f . g $ x) style, and save key strokes.
>
> + In module with RebindableSyntax enabled, you can import ifThenElse to get
> default behavior.
>
>
> Whether or not to be exported by Prelude is another question, but Data.Bool
> seems a good place to start with.
>
>
> Cheers~
>
> Winter
>
>
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-- 
Ivan Lazar Miljenovic
Ivan.Miljenovic at gmail.com
http://IvanMiljenovic.wordpress.com