Le 12/07/2018 à 15:01, Brett Gilio reacts :
Alexey, could you expand on what you mean in your first point? I am quite intrigued. I do not use Haskell often, but that could be something of interest to me in-and-out of Haskell.
Brett Gilio
...major reasons
1. The ability to *define the specification (types) and then "just" follow them in implementation.* Sometimes even without having a clear understanding of the things I was using, I felt (and still feel) guided towards the right solution. I am not Alexey Raga, who precises: when I wrote a signature for my function, the compiler will make its best to help me implement it. It will yell at me, it will not let me use things that I am not supposed to use (according to constraints), etc. === ... but I think that there is more to tell, since in *all languages* the compiler makes its best to profit from typing in order to optimize the implementation... With polymorphic typing and automatic type inference, the compiler can do a little more, it seems that people forgot already the "toy" (not so...) of Lennart Augustsson, named Djinn, which takes a type and
Alexey Raga wrote: proposes an object of this type, using the intuitionistic logic theorem prover (the current Djinn library dates back to 2014, but Lennart manufactured it already in 2006, or before, if I am not mistaken. He quotes Roy Dyckhoff, and Don Stewart). Here is a test: *Djinn> f ? (a,b) -> (b,a) -- my input f :: (a, b) -> (b, a) f (a, b) = (b, a)* Doaitse Swierstra comments:
swap (a, b) = (b, a)
Once you ask for the type you get (a, b) -> (b, a), hence the type completely specifies what swap computes, and/*the function is even more general than the version of the type above*/. I don't see that last point... Anyway, the typing power of Haskell should be known. Thx.
Jerzy Karczmarczuk --- L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast. https://www.avast.com/antivirus