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Language request: Add forAll quantifier / Make MethodTypes first-class

See original GitHub issue

We already have forSome, how about adding a forAll quantifier? Haskell, for instance, has this.

Issue Analytics

State:
Created 6 years ago
Reactions:1
Comments:55 (53 by maintainers)

Top GitHub Comments

5reactions

milessabincommented, Jun 14, 2018

@LPTK there are tricks to do it in Scala 2 too … for Scala 3 we should be aiming to do away with the tricks and make this idiom first class.

What I’d like to see is a direct correspondence between method types (polymorphic, implicit, dependent) and function types … we’re tantalizingly close now, with this being the last piece of the picture.

I don’t particularly like the proposed syntax however. We already have universal quantification for method types, so why not simply reuse it for function types? Taking @LukaJCB’s example, that would allow us to write,

val map: [F[_], A, B](implicit Functor[F]) => F[A] => (A => B) => F[B] = ...

4reactions

oderskycommented, May 24, 2017

forSome has been deprecated 😄

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