Implicit values (types) defined in a for comprehension cannot be properly used right after

[kovacshuni]

Compiler version

3.1.1, 3.1.2

Minimized code

How do you fetch an implicit value in a for comprehension, when its type is parameterized?

for
  o               <- Option("line just to make for comprehension start")
  given Int       = 2
  a               = implicitly[Int] // error: same kind as below
  given List[Int] = List(1, 2, 3)
  b               = implicitly[List[Int]] // error: no implicit argument of type List[Int] was found for parameter e of method implicitly in object Predef
yield ()

Output

no implicit argument of type List[Int] was found for parameter e of method implicitly in object Predef

Expectation

For comprehensions to work cleanly with givens, whether they are defined by a <- or a =.

Would be really great if this worked as implicits and composing dependencies in for comprehensions is fundamental in the tagless final style of coding. Basically the initial part of the application, defining the components makes use of this.

Workaround

But if I insert a dummy line in between the declaration and the usage, it works:

for
  o               <- Option("line just to make for comprehension start")
  given List[Int] = List(1, 2, 3)
  p               <- Option("dummy")
  b               = implicitly[List[Int]] // works
yield ()

[bishabosha]

I think this was fixed by #12646, could you see if it works on 3.2.0-RC1?

[kovacshuni]

Yes, positive.

[kovacshuni]

Thank you for confirming / taking a look.