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nicolasstuckinicolasstucki
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Add reflect TypeLambda.paramVariances (#17568)
Fixes #16734
2 parents 242ba21 + f86a682 commit 40cee39

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‎compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala

+3
Original file line numberDiff line numberDiff line change
@@ -2246,6 +2246,8 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
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extension (self: TypeLambda)
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def param(idx: Int): TypeRepr = self.newParamRef(idx)
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def paramBounds: List[TypeBounds] = self.paramInfos
2249+
def paramVariances: List[Flags] =
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self.typeParams.map(_.paramVariance)
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end extension
22502252
end TypeLambdaMethods
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@@ -2754,6 +2756,7 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
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}
27552757

27562758
def isTypeParam: Boolean = self.isTypeParam
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def paramVariance: Flags = self.paramVariance
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def signature: Signature = self.signature
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def moduleClass: Symbol = self.denot.moduleClass
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def companionClass: Symbol = self.denot.companionClass

‎library/src/scala/quoted/Quotes.scala

+17
Original file line numberDiff line numberDiff line change
@@ -3258,8 +3258,16 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
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/** Extension methods of `TypeLambda` */
32593259
trait TypeLambdaMethods:
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extension (self: TypeLambda)
3261+
/** Reference to the i-th parameter */
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def param(idx: Int) : TypeRepr
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/** Type bounds of the i-th parameter */
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def paramBounds: List[TypeBounds]
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/** Variance flags for the i-th parameter
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*
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* Variance flags can be one of `Flags.{Covariant, Contravariant, EmptyFlags}`.
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*/
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@experimental
3270+
def paramVariances: List[Flags]
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end extension
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end TypeLambdaMethods
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@@ -4078,8 +4086,17 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
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/** Fields of a case class type -- only the ones declared in primary constructor */
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def caseFields: List[Symbol]
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/** Is this the symbol of a type parameter */
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def isTypeParam: Boolean
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4092+
/** Variance flags for of this type parameter.
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*
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* Variance flags can be one of `Flags.{Covariant, Contravariant, EmptyFlags}`.
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* If this is not the symbol of a type parameter the result is `Flags.EmptyFlags`.
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*/
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@experimental
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def paramVariance: Flags
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/** Signature of this definition */
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def signature: Signature
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‎tests/run-macros/i16734a.check

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,67 @@
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[F >: scala.Nothing <: [A >: scala.Nothing <: scala.Any] =>> scala.Any] =>> K1Inv[F]
2+
F
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A
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5+
[F >: scala.Nothing <: [A >: scala.Nothing <: scala.Any] =>> scala.Any] =>> K1Cov[F]
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F
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+A
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[F >: scala.Nothing <: [A >: scala.Nothing <: scala.Any] =>> scala.Any] =>> K1Con[F]
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F
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-A
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[F >: scala.Nothing <: [A >: scala.Nothing <: scala.Any, B >: scala.Nothing <: scala.Any] =>> scala.Any] =>> K2InvInv[F]
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F
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A, B
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[F >: scala.Nothing <: [A >: scala.Nothing <: scala.Any, B >: scala.Nothing <: scala.Any] =>> scala.Any] =>> K2InvCov[F]
18+
F
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A, +B
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[F >: scala.Nothing <: [A >: scala.Nothing <: scala.Any, B >: scala.Nothing <: scala.Any] =>> scala.Any] =>> K2InvCon[F]
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F
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A, -B
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[F >: scala.Nothing <: [A >: scala.Nothing <: scala.Any, B >: scala.Nothing <: scala.Any] =>> scala.Any] =>> K2CovInv[F]
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F
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+A, B
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[F >: scala.Nothing <: [A >: scala.Nothing <: scala.Any, B >: scala.Nothing <: scala.Any] =>> scala.Any] =>> K2CovCov[F]
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F
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+A, +B
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[F >: scala.Nothing <: [A >: scala.Nothing <: scala.Any, B >: scala.Nothing <: scala.Any] =>> scala.Any] =>> K2CovCon[F]
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F
35+
+A, -B
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[F >: scala.Nothing <: [A >: scala.Nothing <: scala.Any, B >: scala.Nothing <: scala.Any] =>> scala.Any] =>> K2ConInv[F]
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F
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-A, B
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[F >: scala.Nothing <: [A >: scala.Nothing <: scala.Any, B >: scala.Nothing <: scala.Any] =>> scala.Any] =>> K2ConCov[F]
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F
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-A, +B
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[F >: scala.Nothing <: [A >: scala.Nothing <: scala.Any, B >: scala.Nothing <: scala.Any] =>> scala.Any] =>> K2ConCon[F]
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F
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-A, -B
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[G >: scala.Nothing <: [A >: scala.Nothing <: scala.Any, B >: scala.Nothing <: scala.Any, C >: scala.Nothing <: scala.Any, D >: scala.Nothing <: [X1 >: scala.Nothing <: scala.Any, Y1 >: scala.Nothing <: scala.Any, Z1 >: scala.Nothing <: scala.Any] =>> scala.Any, E >: scala.Nothing <: [X2 >: scala.Nothing <: scala.Any, Y2 >: scala.Nothing <: scala.Any, Z2 >: scala.Nothing <: scala.Any] =>> scala.Any, F >: scala.Nothing <: [X3 >: scala.Nothing <: scala.Any, Y3 >: scala.Nothing <: scala.Any, Z3 >: scala.Nothing <: scala.Any] =>> scala.Any] =>> scala.Any] =>> KFunky[G]
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G
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A, +B, -C, D, +E, -F
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X1, +Y1, -Z1
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X2, +Y2, -Z2
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X3, +Y3, -Z3
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[A >: scala.Nothing <: scala.Any, F >: scala.Nothing <: [B >: scala.Nothing <: scala.Any] =>> scala.Any] =>> F[A]
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A, +F
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B
59+
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[A >: scala.Nothing <: scala.Any, F >: scala.Nothing <: [B >: scala.Nothing <: scala.Any] =>> scala.Any] =>> F[A]
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+A, +F
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+B
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[A >: scala.Nothing <: scala.Any, F >: scala.Nothing <: [B >: scala.Nothing <: scala.Any] =>> scala.Any] =>> F[A]
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-A, +F
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-B
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‎tests/run-macros/i16734a/Macro_1.scala

+21
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@@ -0,0 +1,21 @@
1+
import scala.quoted.*
2+
3+
inline def variances[A <: AnyKind]: String =
4+
${variancesImpl[A]}
5+
6+
def variancesImpl[A <: AnyKind: Type](using Quotes): Expr[String] =
7+
import quotes.reflect.*
8+
def loop(tpe: TypeRepr): List[String] =
9+
tpe match
10+
case tpe: TypeLambda =>
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tpe.paramNames.zip(tpe.paramVariances).map { (name, variance) =>
12+
if variance == Flags.Covariant then "+" + name
13+
else if variance == Flags.Contravariant then "-" + name
14+
else name
15+
}.mkString(", ") :: tpe.paramTypes.flatMap(loop)
16+
case tpe: TypeBounds =>
17+
loop(tpe.low) ++ loop(tpe.hi)
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case _ =>
19+
Nil
20+
val res = (Type.show[A] :: loop(TypeRepr.of[A])).mkString("", "\n", "\n")
21+
Expr(res)

‎tests/run-macros/i16734a/Test_2.scala

+34
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@@ -0,0 +1,34 @@
1+
trait K1Inv[F[A]]
2+
trait K1Cov[F[+A]]
3+
trait K1Con[F[-A]]
4+
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trait K2InvInv[F[A, B]]
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trait K2InvCov[F[A, +B]]
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trait K2InvCon[F[A, -B]]
8+
trait K2CovInv[F[+A, B]]
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trait K2CovCov[F[+A, +B]]
10+
trait K2CovCon[F[+A, -B]]
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trait K2ConInv[F[-A, B]]
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trait K2ConCov[F[-A, +B]]
13+
trait K2ConCon[F[-A, -B]]
14+
15+
16+
trait KFunky[G[A, +B, -C, D[X1, +Y1, -Z1], +E[X2, +Y2, -Z2], -F[X3, +Y3, -Z3]]]
17+
18+
@main def Test =
19+
println(variances[K1Inv])
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println(variances[K1Cov])
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println(variances[K1Con])
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println(variances[K2InvInv])
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println(variances[K2InvCov])
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println(variances[K2InvCon])
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println(variances[K2CovInv])
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println(variances[K2CovCov])
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println(variances[K2CovCon])
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println(variances[K2ConInv])
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println(variances[K2ConCov])
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println(variances[K2ConCon])
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println(variances[KFunky])
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println(variances[[A, F[B]] =>> F[A]])
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println(variances[[A, F[+B]] =>> F[A]])
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println(variances[[A, F[-B]] =>> F[A]])

‎tests/run-macros/i16734b.check

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@@ -0,0 +1,36 @@
1+
type F1Inv
2+
A
3+
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type F1Cov
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+A
6+
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type F1Con
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-A
9+
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type F2InvInv
11+
A, B
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13+
type F2InvCov
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A, +B
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type F2InvCon
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A, -B
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type F2CovInv
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+A, B
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type F2CovCov
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+A, +B
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type F2CovCon
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+A, -B
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type F2ConInv
29+
-A, B
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type F2ConCov
32+
-A, +B
33+
34+
type F2ConCon
35+
-A, -B
36+

‎tests/run-macros/i16734b/Macro_1.scala

+14
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@@ -0,0 +1,14 @@
1+
import scala.quoted.*
2+
3+
inline def typeVariances[A <: AnyKind]: String =
4+
${variancesImpl[A]}
5+
6+
def variancesImpl[A <: AnyKind: Type](using Quotes): Expr[String] =
7+
import quotes.reflect.*
8+
val TypeBounds(_, tl: TypeLambda) = TypeRepr.of[A].typeSymbol.info: @unchecked
9+
val variances = tl.paramNames.zip(tl.paramVariances).map { (name, variance) =>
10+
if variance == Flags.Covariant then "+" + name
11+
else if variance == Flags.Contravariant then "-" + name
12+
else name
13+
}.mkString(", ")
14+
Expr(TypeRepr.of[A].typeSymbol.toString() + "\n" + variances + "\n")

‎tests/run-macros/i16734b/Test_2.scala

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,27 @@
1+
type F1Inv[A]
2+
type F1Cov[+A]
3+
type F1Con[-A]
4+
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type F2InvInv[A, B]
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type F2InvCov[A, +B]
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type F2InvCon[A, -B]
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type F2CovInv[+A, B]
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type F2CovCov[+A, +B]
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type F2CovCon[+A, -B]
11+
type F2ConInv[-A, B]
12+
type F2ConCov[-A, +B]
13+
type F2ConCon[-A, -B]
14+
15+
@main def Test =
16+
println(typeVariances[F1Inv])
17+
println(typeVariances[F1Cov])
18+
println(typeVariances[F1Con])
19+
println(typeVariances[F2InvInv])
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println(typeVariances[F2InvCov])
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println(typeVariances[F2InvCon])
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println(typeVariances[F2CovInv])
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println(typeVariances[F2CovCov])
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println(typeVariances[F2CovCon])
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println(typeVariances[F2ConInv])
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println(typeVariances[F2ConCov])
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println(typeVariances[F2ConCon])

‎tests/run-macros/i16734c.check

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@@ -0,0 +1,36 @@
1+
class C1Inv
2+
A
3+
4+
class C1Cov
5+
+A
6+
7+
class C1Con
8+
-A
9+
10+
class C2InvInv
11+
A, B
12+
13+
class C2InvCov
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A, +B
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16+
class C2InvCon
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A, -B
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19+
class C2CovInv
20+
+A, B
21+
22+
class C2CovCov
23+
+A, +B
24+
25+
class C2CovCon
26+
+A, -B
27+
28+
class C2ConInv
29+
-A, B
30+
31+
class C2ConCov
32+
-A, +B
33+
34+
class C2ConCon
35+
-A, -B
36+

‎tests/run-macros/i16734c/Macro_1.scala

+14
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@@ -0,0 +1,14 @@
1+
import scala.quoted.*
2+
3+
inline def classVariances[A <: AnyKind]: String =
4+
${variancesImpl[A]}
5+
6+
def variancesImpl[A <: AnyKind: Type](using Quotes): Expr[String] =
7+
import quotes.reflect.*
8+
val variances = TypeRepr.of[A].typeSymbol.typeMembers.filter(_.isTypeParam).map { sym =>
9+
if sym.paramVariance == Flags.Covariant then "+" + sym.name
10+
else if sym.paramVariance == Flags.Contravariant then "-" + sym.name
11+
else sym.name
12+
}
13+
val res = variances.mkString(TypeRepr.of[A].typeSymbol.toString + "\n", ", ", "\n")
14+
Expr(res)

‎tests/run-macros/i16734c/Test_2.scala

+27
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@@ -0,0 +1,27 @@
1+
class C1Inv[A] { type T }
2+
class C1Cov[+A] { type T }
3+
class C1Con[-A] { type T }
4+
5+
class C2InvInv[A, B] { type T }
6+
class C2InvCov[A, +B] { type T }
7+
class C2InvCon[A, -B] { type T }
8+
class C2CovInv[+A, B] { type T }
9+
class C2CovCov[+A, +B] { type T }
10+
class C2CovCon[+A, -B] { type T }
11+
class C2ConInv[-A, B] { type T }
12+
class C2ConCov[-A, +B] { type T }
13+
class C2ConCon[-A, -B] { type T }
14+
15+
@main def Test =
16+
println(classVariances[C1Inv])
17+
println(classVariances[C1Cov])
18+
println(classVariances[C1Con])
19+
println(classVariances[C2InvInv])
20+
println(classVariances[C2InvCov])
21+
println(classVariances[C2InvCon])
22+
println(classVariances[C2CovInv])
23+
println(classVariances[C2CovCov])
24+
println(classVariances[C2CovCon])
25+
println(classVariances[C2ConInv])
26+
println(classVariances[C2ConCov])
27+
println(classVariances[C2ConCon])

‎tests/run-tasty-inspector/stdlibExperimentalDefinitions.scala

+2
Original file line numberDiff line numberDiff line change
@@ -68,6 +68,8 @@ val experimentalDefinitionInLibrary = Set(
6868
"scala.annotation.init$.region",
6969

7070
//// New APIs: Quotes
71+
"scala.quoted.Quotes.reflectModule.TypeLambdaMethods.paramVariances",
72+
"scala.quoted.Quotes.reflectModule.SymbolMethods.paramVariance",
7173
// Can be stabilized in 3.4.0 (unsure) or later
7274
"scala.quoted.Quotes.reflectModule.CompilationInfoModule.XmacroSettings",
7375
"scala.quoted.Quotes.reflectModule.FlagsModule.JavaAnnotation",

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