Use canonical underlying type reference #10110
Conversation
nicolasstucki
force-pushed
the
use-canonical-undelying-type
branch
from
40b8801 to
8afec66
Compare
| @@ -4,7 +4,7 @@ import scala.quoted._ | |||
| object Test { | |||
| def loop[T](x: Expr[T])(implicit t: Type[T], qctx: QuoteContext): Expr[T] = '{ | |||
| val y: t.Underlying = $x; | |||
| ${loop[t.Underlying]( // error | |||
| ${loop[t.Underlying]( | |||
There was a problem hiding this comment.
This was actually crashing with an assertion failure at
8afec66#diff-b3069d0753da3a2c12847b53d12eaf5d5003af1d6e6438c84f1dd5f6ef6a668eL218.
This also happens on master.
There was a problem hiding this comment.
I did not open an issue as the fix was straightforward.
| } | ||
|
|
||
| { | ||
| val s = '{Option.empty[${T}]} // works | ||
| val s = '{Option.empty[T.Underlying]} // works |
There was a problem hiding this comment.
| val s = '{Option.empty[T.Underlying]} // works | |
| val s = '{Option.empty[T]} // works |
There was a problem hiding this comment.
It is equivalent but should not be changed to keep testing the same thing.
There was a problem hiding this comment.
For example, the second commit found the bug because I kept it as T.Underlying.
| val r1 = '{Option.empty[T.Underlying]} // works | ||
| val r2 = '{Option.empty[List[T.Underlying]]} // works | ||
| val r3 = '{summon[Type[T.Underlying]]} // error: is not stable | ||
| val r4 = '{summon[T.Underlying <:< Any]} // error: is not stable |
There was a problem hiding this comment.
It's a little surprising that List[T.Underlying] works but summon[Type[T.Underlying]]] is an error.
There was a problem hiding this comment.
This one was subtle.
[error] (Test.this.given_Type_T : => quoted.Type[Test.this.T]) is not a valid type witness, since it is not an immutable path
The issue is that given Type[T] = getT is not stable. This is where I usually write given getT.type = getT to not lose the path in the given.
The other cases happen to work because we only referred to T.Underlying and never needed to head some type. This is the expected behavior.
| else report.warning(msg, tree.srcPos) | ||
| // if sourceVersion.isAtLeast(`3.1-migration`) then | ||
| report.error(msg, tree.srcPos) | ||
| // else report.warning(msg, tree.srcPos) |
There was a problem hiding this comment.
So we decide to enforce it in M1? That's fine, just make sure it's not an accidental change.
There was a problem hiding this comment.
I need to revert this change
nicolasstucki
force-pushed
the
use-canonical-undelying-type
branch
from
8afec66 to
a779493
Compare
No description provided.