Slow Type Check (Result in slow compile time)

[jeffersonsetiawan]

I loved Prelude and used it a lot in my projects.

But recently, one of member in my team found out that if we use a lot of it, it cause slow type check (he used 8 pipe) like this

let a8: TestingOnly = TestingOnly(a: true)
            |> \.a .~ false
            |> \.a .~ false
            |> \.a .~ false
            |> \.a .~ false
            |> \.a .~ false
            |> \.a .~ false
            |> \.a .~ false
            |> \.a .~ false

and the type check can be as slow as 10s.

For temporary solution I suggest my team not to use lot of pipe chaining to have faster type checking or breaking it to smaller chunks

Demo project: https://github.com/jeffersonsetiawan/SlowTypeCheckLens

Really appreciate if someone can make this faster 🙏🏻

[stephencelis]

Sorry for the radio silence in this repo. It's more of an experimental one compared to our more publicly maintained ones!

This is unfortunately a limitation of the Swift compiler and not something we can solve at the library-level. Our "fix" is the same as the one you suggest (breaking the expression down into smaller ones).

Going to migrate this to a discussion for now, thanks!