Bound TypeRepr by Matchable in Quotes

[hamzaremmal]

Closes #21282

[sjrd]

Is that not intended? Can we safely match on TypeReprs?

[hamzaremmal]

Is that not intended? Can we safely match on TypeReprs?

Yes, we can safely match over TypeRepr (under the assumption that only the compiler implements Quotes). We also provide instances of TypeTest, for example:

scala3/library/src/scala/quoted/Quotes.scala

Line 2811 in 1913367

given ConstantTypeTypeTest: TypeTest[TypeRepr, ConstantType]

[jchyb]

LGTM. Thank you!
We might need to go through some other types in Quotes.scala like ImplicitSearchResult, Tree, even some TypeRepr subtypes like AndOrType and also add Matchable there. I'll try to prepare an issue for that and fix it later today.

[hamzaremmal]

LGTM. Thank you! We might need to go through some other types in Quotes.scala like ImplicitSearchResult, Tree, even some TypeRepr subtypes like AndOrType and also add Matchable there. I'll try to prepare an issue for that and fix it later today.

I agree, I'm sure there are some other types we need to bind but I didn't want to include these changes here as it closes a specific issue. We don't need to do anything more for subtypes of TypeRepr, the will all be bound by Matchable since now TypeRepr is bound by Matchable:

scala3/library/src/scala/quoted/Quotes.scala

Line 2997 in b64afad

type AndOrType <: TypeRepr

For Tree and ImplicitSearchResult, the types are already bound by AnyRef and therefore Matchable:

scala3/library/src/scala/quoted/Quotes.scala

Line 283 in b64afad

type Tree <: AnyRef

scala3/library/src/scala/quoted/Quotes.scala

Line 3711 in b64afad

type ImplicitSearchResult <: AnyRef

Nevertheless, a check is welcome.

[jchyb]

Ah, good point!