value + is not a member of Int

[scarf005]

Compiler version

3.7.0

Minimized example

(1, 2).map([Int] => (x: Int) => x + 1)

Output Error/Warning message

scala> (1, 2).map([Int] => (x: Int) => x + 1)
-- [E008] Not Found Error: --------------------------------------------------------------------------------------
1 |(1, 2).map([Int] => (x: Int) => x + 1)
  |                                ^^^
  |                        value + is not a member of Int, but could be made available as an extension method.
  |
  |                        One of the following imports might make progress towards fixing the problem:
  |
  |                          import scala.math.Fractional.Implicits.infixFractionalOps
  |                          import scala.math.Integral.Implicits.infixIntegralOps
  |                          import scala.math.Numeric.Implicits.infixNumericOps
  |
1 error found

Why this Error/Warning was not helpful

the error message value + is not a member of Int is very confusing because 1 + 1 = 2

Suggested improvement

probably same as #10082

[bishabosha]

so i was not sure if your intention here was for the function to work with scala.Int or to illustrate an error message that doesnt hint the user in the right direction.

If the first case then the error is because [Int] => (i: Int) => i + 1 means "create a generic function with a generic type parameter called Int (unrelated to scala.Int) and use the generic type parameter as the type of parameter i of the function"

possible solutions, perhaps in type errors we can hint if generic type parameters names shadow any other types visible from the scope?

[scarf005]

sorry, lacked some context:
after reading https://discord.com/channels/632150470000902164/632150470000902166/1372495676637708390 i was testing how to map over a tuple (intuition: (1, 2).map(_ + 1) == (2, 3)), and stumbled upon this error message.

i remember scala error messages showing ABC is not equal to ABC²; foo.bar.ABC is not equal to baz.qux.ABC; maybe this one could use the same method.

[som-snytt]

There is a proposal somewhere to run refchecks after erroring before refchecks.

It should also run -Wall checks.

In this case, the shadowing Int does not (yet) warn under -Wshadow:something-something.

-Wshadow:type-parameter-shadow

-- Warning: /home/amarki/snips/i23167.scala:4:6 --------------------------------
4 |def f[Int] = (x: Int) => ???
  |      ^^^
  |Type parameter Int for method f shadows the type defined by class Int in package scala
-- [E198] Unused Symbol Warning: /home/amarki/snips/i23167.scala:4:14 ----------
4 |def f[Int] = (x: Int) => ???
  |              ^
  |              unused explicit parameter
-- [E198] Unused Symbol Warning: /home/amarki/snips/i23167.scala:6:18 ----------
6 |def g = [Int] => (x: Int) => ???
  |                  ^
  |                  unused explicit parameter