No way to list the type parameters from a quotes Symbol or TypeRepr

[cchantep]

It's not possible in quotes to do something like:

def foo(s: Symbol): List[Symbol] = s.typeParams

In dotc it's possible to:

def foo(s: Symbol)(using Context): List[TypeSymbol] = s.denot.typeParams

[nicolasstucki]

This is a bit trickier than it would seem. The assumption above is that there is a single type argument list. This is not necessarily true as some definitions can have multiple type parameter lists. For example

extension [A](a: A) def f[B](b: B): C = ???
// becomes internally
def f[A](a: A)[B](b: B): C

[nicolasstucki]

Currently, the idea is to get the DefDef from the Symbol and then use one of the paramss, leadingTypeParams, trailingParamss, termParamss.

[cchantep]

For me, the type arguments/parameters on the functions through extension don't correspond to the definition of resolving the type arguments/parameters.