GHCI says we all drink left-handed

Andreas Abel abela at chalmers.se
Sat Apr 1 12:17:25 UTC 2017


Indeed.  But

   all (const True) _ == True

does not really come as surprise.  Not really usable as a joke, the 
element of surprise is lacking!

On 01.04.2017 13:36, Jon Purdy wrote:
> If we assume that you drink beer:
>
>     let drink beer = True
>
> Then we can conclude that it doesn’t matter which hand you drink with:
>
>     all drink (Left Handed) == all drink (Right Handed) == True
>
> On Sat, Apr 1, 2017 at 4:08 AM, Andreas Abel <abela at chalmers.se
> <mailto:abela at chalmers.se>> wrote:
>
>     GHCi, version 7.10.3: http://www.haskell.org/ghc/  :? for help
>     Prelude> data Handed = Handed
>     Prelude> let drink beer = beer
>     Prelude> all drink (Left Handed)
>     True
>
>     --
>     Andreas Abel  <><      Du bist der geliebte Mensch.
>
>     Department of Computer Science and Engineering
>     Chalmers and Gothenburg University, Sweden
>
>     andreas.abel at gu.se <mailto:andreas.abel at gu.se>
>     http://www.cse.chalmers.se/~abela/ <http://www.cse.chalmers.se/~abela/>
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>

-- 
Andreas Abel  <><      Du bist der geliebte Mensch.

Department of Computer Science and Engineering
Chalmers and Gothenburg University, Sweden

andreas.abel at gu.se
http://www.cse.chalmers.se/~abela/


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