Drop @unbox annotation

library/src/scala/caps.scala

@@ -52,11 +52,6 @@ import annotation.{experimental, compileTimeOnly, retainsCap}
    */
   final class untrackedCaptures extends annotation.StaticAnnotation
 
-  /** This should go into annotations. For now it is here, so that we
-   *  can experiment with it quickly between minor releases
-   */
-  final class unbox extends annotation.StaticAnnotation
-
   object unsafe:
 
     extension [T](x: T)

tests/neg-custom-args/captures/i15749a.scala

@@ -1,5 +1,4 @@
 import caps.cap
-import caps.unbox
 
 class Unit
 object u extends Unit
@@ -18,7 +17,7 @@ def test =
 
   def force[A](thunk: Unit ->{cap} A): A = thunk(u)
 
-  def forceWrapper[A](@unbox mx: Wrapper[Unit ->{cap} A]): Wrapper[A] =
+  def forceWrapper[A](mx: Wrapper[Unit ->{cap} A]): Wrapper[A] =
     // Γ ⊢ mx: Wrapper[□ {cap} Unit => A]
     // `force` should be typed as ∀(□ {cap} Unit -> A) A, but it can not
     strictMap[Unit ->{mx*} A, A](mx)(t => force[A](t)) // error // should work

tests/neg-custom-args/captures/i21614.check

@@ -1,12 +1,12 @@
--- [E007] Type Mismatch Error: tests/neg-custom-args/captures/i21614.scala:9:33 ----------------------------------------
-9 |  files.map((f: F) => new Logger(f)) // error, Q: can we make this pass (see #19076)?
+-- [E007] Type Mismatch Error: tests/neg-custom-args/captures/i21614.scala:8:33 ----------------------------------------
+8 |  files.map((f: F) => new Logger(f)) // error, Q: can we make this pass (see #19076)?
   |                                 ^
   |                                 Found:    (f : F^)
   |                                 Required: File^
   |
   | longer explanation available when compiling with `-explain`
--- [E007] Type Mismatch Error: tests/neg-custom-args/captures/i21614.scala:12:12 ---------------------------------------
-12 |  files.map(new Logger(_)) // error, Q: can we improve the error message?
+-- [E007] Type Mismatch Error: tests/neg-custom-args/captures/i21614.scala:11:12 ---------------------------------------
+11 |  files.map(new Logger(_)) // error, Q: can we improve the error message?
    |            ^^^^^^^^^^^^^
    |            Found:    Logger{val f: (_$1 : File^{files*})}^
    |            Required: Logger{val f: File^?}^?

tests/neg-custom-args/captures/i21614.scala

@@ -1,12 +1,11 @@
 import language.experimental.captureChecking
 import caps.Capability
-import caps.unbox
 
 trait File extends Capability
 class Logger(f: File^) extends Capability // <- will work if we remove the extends clause
 
-def mkLoggers1[F <: File^](@unbox files: List[F]): List[Logger^] =
+def mkLoggers1[F <: File^](files: List[F]): List[Logger^] =
   files.map((f: F) => new Logger(f)) // error, Q: can we make this pass (see #19076)?
 
-def mkLoggers2(@unbox files: List[File^]): List[Logger^] =
+def mkLoggers2(files: List[File^]): List[Logger^] =
   files.map(new Logger(_)) // error, Q: can we improve the error message?

tests/neg-custom-args/captures/leak-problem-2.scala

@@ -2,7 +2,7 @@ import language.experimental.captureChecking
 
 trait Source[+T]
 
-def race[T](@caps.unbox sources: Seq[Source[T]^]): Source[T]^{sources*} = ???
+def race[T](sources: Seq[Source[T]^]): Source[T]^{sources*} = ???
 
 def raceTwo[T](src1: Source[T]^, src2: Source[T]^): Source[T]^{}
   = race(Seq(src1, src2)) // error

tests/neg-custom-args/captures/reaches.check

@@ -1,12 +1,12 @@
--- [E007] Type Mismatch Error: tests/neg-custom-args/captures/reaches.scala:22:11 --------------------------------------
-22 |    cur = (() => f.write()) :: Nil // error
+-- [E007] Type Mismatch Error: tests/neg-custom-args/captures/reaches.scala:21:11 --------------------------------------
+21 |    cur = (() => f.write()) :: Nil // error
    |           ^^^^^^^^^^^^^^^^^^^^^^^
    |           Found:    List[box () ->{f} Unit]
    |           Required: List[box () ->{xs*} Unit]
    |
    | longer explanation available when compiling with `-explain`
--- [E007] Type Mismatch Error: tests/neg-custom-args/captures/reaches.scala:33:7 ---------------------------------------
-33 |      (() => f.write()) :: Nil // error
+-- [E007] Type Mismatch Error: tests/neg-custom-args/captures/reaches.scala:32:7 ---------------------------------------
+32 |      (() => f.write()) :: Nil // error
    |       ^^^^^^^^^^^^^^^^^^^^^^^
    |       Found:    List[box () ->{f} Unit]
    |       Required: box List[box () ->{xs*} Unit]^?
@@ -15,40 +15,40 @@
    |       cannot be included in outer capture set {xs*} of value cur
    |
    | longer explanation available when compiling with `-explain`
--- Error: tests/neg-custom-args/captures/reaches.scala:38:31 -----------------------------------------------------------
-38 |    val next: () => Unit = cur.head // error
+-- Error: tests/neg-custom-args/captures/reaches.scala:37:31 -----------------------------------------------------------
+37 |    val next: () => Unit = cur.head // error
    |                           ^^^^^^^^
    |                       The expression's type box () => Unit is not allowed to capture the root capability `cap`.
    |                       This usually means that a capability persists longer than its allowed lifetime.
--- Error: tests/neg-custom-args/captures/reaches.scala:45:35 -----------------------------------------------------------
-45 |    val next: () => Unit = cur.get.head // error
+-- Error: tests/neg-custom-args/captures/reaches.scala:44:35 -----------------------------------------------------------
+44 |    val next: () => Unit = cur.get.head // error
    |                           ^^^^^^^^^^^^
    |                       The expression's type box () => Unit is not allowed to capture the root capability `cap`.
    |                       This usually means that a capability persists longer than its allowed lifetime.
--- [E007] Type Mismatch Error: tests/neg-custom-args/captures/reaches.scala:53:2 ---------------------------------------
-53 |  val id: Id[Proc, Proc] = new Id[Proc, () -> Unit] // error
+-- [E007] Type Mismatch Error: tests/neg-custom-args/captures/reaches.scala:52:2 ---------------------------------------
+52 |  val id: Id[Proc, Proc] = new Id[Proc, () -> Unit] // error
    |  ^
    |  Found:    box () => Unit
    |  Required: () => Unit
    |
    |  Note that box () => Unit cannot be box-converted to () => Unit
    |  since at least one of their capture sets contains the root capability `cap`
-54 |  usingFile: f =>
-55 |    id(() => f.write())
+53 |  usingFile: f =>
+54 |    id(() => f.write())
    |
    | longer explanation available when compiling with `-explain`
--- [E007] Type Mismatch Error: tests/neg-custom-args/captures/reaches.scala:62:27 --------------------------------------
-62 |    val f1: File^{id*} = id(f) // error, since now id(f): File^ // error
+-- [E007] Type Mismatch Error: tests/neg-custom-args/captures/reaches.scala:61:27 --------------------------------------
+61 |    val f1: File^{id*} = id(f) // error, since now id(f): File^ // error
    |                         ^^^^^
    |                         Found:    File^{f}
    |                         Required: File^{id*}
    |
    | longer explanation available when compiling with `-explain`
--- Error: tests/neg-custom-args/captures/reaches.scala:61:31 -----------------------------------------------------------
-61 |  val leaked = usingFile[File^{id*}]: f => // error
+-- Error: tests/neg-custom-args/captures/reaches.scala:60:31 -----------------------------------------------------------
+60 |  val leaked = usingFile[File^{id*}]: f => // error
    |                               ^^^
    |                               id* cannot be tracked since its capture set is empty
--- Error: tests/neg-custom-args/captures/reaches.scala:62:18 -----------------------------------------------------------
-62 |    val f1: File^{id*} = id(f) // error, since now id(f): File^ // error
+-- Error: tests/neg-custom-args/captures/reaches.scala:61:18 -----------------------------------------------------------
+61 |    val f1: File^{id*} = id(f) // error, since now id(f): File^ // error
    |                  ^^^
    |                  id* cannot be tracked since its capture set is empty

tests/neg-custom-args/captures/reaches.scala

@@ -1,4 +1,3 @@
-import caps.unbox
 class File:
   def write(): Unit = ???
 
@@ -11,7 +10,7 @@ class Ref[T](init: T):
   def get: T = x
   def set(y: T) = { x = y }
 
-def runAll0(@unbox xs: List[Proc]): Unit =
+def runAll0(xs: List[Proc]): Unit =
   var cur: List[() ->{xs*} Unit] = xs
   while cur.nonEmpty do
     val next: () ->{xs*} Unit = cur.head
@@ -21,7 +20,7 @@ def runAll0(@unbox xs: List[Proc]): Unit =
   usingFile: f =>
     cur = (() => f.write()) :: Nil // error
 
-def runAll1(@unbox xs: List[Proc]): Unit =
+def runAll1(xs: List[Proc]): Unit =
   val cur = Ref[List[() ->{xs*} Unit]](xs)  // OK, by revised VAR
   while cur.get.nonEmpty do
     val next: () ->{xs*} Unit = cur.get.head

tests/neg-custom-args/captures/spread-problem.scala

@@ -2,7 +2,7 @@ import language.experimental.captureChecking
 
 trait Source[+T]
 
-def race[T](@caps.unbox sources: (Source[T]^)*): Source[T]^{sources*} = ???
+def race[T](sources: (Source[T]^)*): Source[T]^{sources*} = ???
 
 def raceTwo[T](src1: Source[T]^, src2: Source[T]^): Source[T]^{} =
   race(Seq(src1, src2)*) // error

tests/pos-custom-args/captures/dep-reach.scala

@@ -1,10 +1,9 @@
-import caps.unbox
 object Test:
   class C
   type Proc = () => Unit
 
   def f(c: C^, d: C^): () ->{c, d} Unit =
-    def foo(@unbox xs: Proc*): () ->{xs*} Unit =
+    def foo(xs: Proc*): () ->{xs*} Unit =
       xs.head
     val a: () ->{c} Unit = () => ()
     val b: () ->{d} Unit = () => ()
@@ -13,7 +12,7 @@ object Test:
 
   def g(c: C^, d: C^): () ->{c, d} Unit =
 
-    def foo(@unbox xs: Seq[() => Unit]): () ->{xs*} Unit =
+    def foo(xs: Seq[() => Unit]): () ->{xs*} Unit =
       xs.head
 
     val a: () ->{c} Unit = () => ()

tests/pos-custom-args/captures/i20503.scala

@@ -1,5 +1,4 @@
 import language.experimental.captureChecking
-import caps.unbox
 
 class List[+A]:
   def head: A = ???
@@ -8,7 +7,7 @@ class List[+A]:
   def foreach[U](f: A => U): Unit = ???
   def nonEmpty: Boolean = ???
 
-def runOps(@unbox ops: List[() => Unit]): Unit =
+def runOps(ops: List[() => Unit]): Unit =
   // See i20156, due to limitation in expressiveness of current system,
   // we could map over the list of impure elements. OK with existentials.
   ops.foreach(op => op())

tests/pos-custom-args/captures/reaches.scala

@@ -1,4 +1,3 @@
-import caps.unbox
 
 class C
 def f(xs: List[C^]) =
@@ -22,7 +21,7 @@ extension [A](x: A) def :: (xs: List[A]): List[A] = ???
 
 object Nil extends List[Nothing]
 
-def runAll(@unbox xs: List[Proc]): Unit =
+def runAll(xs: List[Proc]): Unit =
   var cur: List[() ->{xs*} Unit] = xs  // OK, by revised VAR
   while cur.nonEmpty do
     val next: () ->{xs*} Unit = cur.head

tests/pos/cc-poly-source-capability.scala

@@ -1,7 +1,6 @@
 import language.experimental.captureChecking
 import annotation.experimental
 import caps.{CapSet, Capability}
-import caps.unbox
 
 @experimental object Test:
 
@@ -18,7 +17,7 @@ import caps.unbox
 
     def allListeners: Set[Listener^{X^}] = listeners
 
-  def test1(async1: Async, @unbox others: List[Async]) =
+  def test1(async1: Async, others: List[Async]) =
     val src = Source[CapSet^{async1, others*}]
     val lst1 = listener(async1)
     val lsts = others.map(listener)

tests/pos/cc-poly-source.scala

@@ -1,7 +1,6 @@
 import language.experimental.captureChecking
 import annotation.experimental
 import caps.{CapSet, Capability}
-import caps.unbox
 
 @experimental object Test:
 
@@ -25,7 +24,7 @@ import caps.unbox
     val ls = src.allListeners
     val _: Set[Listener^{lbl1, lbl2}] = ls
 
-  def test2(@unbox lbls: List[Label^]) =
+  def test2(lbls: List[Label^]) =
     def makeListener(lbl: Label^): Listener^{lbl} = ???
     val listeners = lbls.map(makeListener)
     val src = Source[CapSet^{lbls*}]

tests/pos/gears-probem-1.scala

@@ -1,5 +1,4 @@
 import language.experimental.captureChecking
-import caps.unbox
 
 trait Future[+T]:
   def await: T
@@ -17,7 +16,7 @@ class Result[+T, +E]:
 case class Err[+E](e: E) extends Result[Nothing, E]
 case class Ok[+T](x: T) extends Result[T, Nothing]
 
-extension [T](@unbox fs: Seq[Future[T]^])
+extension [T](fs: Seq[Future[T]^])
   def awaitAll =
     val collector//: Collector[T]{val futures: Seq[Future[T]^{fs*}]}
        = Collector(fs)

tests/pos/i13541.scala

@@ -6,7 +6,7 @@ object Z:
 type Foo[B] = [A] =>> Bar[A, B]
 trait Bar[A, B]
 
-given fooUnit[A: F]: Foo[Unit][A] = ???
+given fooUnit: [A: F] => Foo[Unit][A] = ???
 //given bar[A: F]: Bar[A, Unit] = ???
 
 def f[A: F](using Foo[Unit][A]): Nothing = ???

tests/pos/i18699.scala

@@ -1,9 +1,8 @@
 import language.experimental.captureChecking
-import caps.unbox
 
 trait Cap:
   def use: Int = 42
 
-def test2(@unbox cs: List[Cap^]): Unit =
+def test2(cs: List[Cap^]): Unit =
   val t0: Cap^{cs*} = cs.head  // error
   var t1: Cap^{cs*} = cs.head  // error

tests/pos/i20342.scala

@@ -1,8 +1,8 @@
 class Repo[EC, E](using defaults: RepoDefaults[EC, E])
 trait RepoDefaults[EC, E]
 object RepoDefaults:
-  inline given genImmutableRepo[E: DbCodec]: RepoDefaults[E, E] = ???
-  inline given genRepo[EC: DbCodec, E: DbCodec]: RepoDefaults[EC, E] = ???
+  inline given genImmutableRepo: [E: DbCodec] => RepoDefaults[E, E] = ???
+  inline given genRepo: [EC: DbCodec, E: DbCodec] => RepoDefaults[EC, E] = ???
 
 trait DbCodec[E]
 

tests/pos/reach-capability.scala

@@ -1,7 +1,6 @@
 import language.experimental.captureChecking
 import annotation.experimental
 import caps.Capability
-import caps.unbox
 
 @experimental object Test2:
 
@@ -12,7 +11,7 @@ import caps.unbox
 
   class Listener
 
-  def test2(@unbox lbls: List[Label]) =
+  def test2(lbls: List[Label]) =
     def makeListener(lbl: Label): Listener^{lbl} = ???
     val listeners = lbls.map(makeListener) // should work
 

tests/pos/reach-problem.scala

@@ -1,11 +1,10 @@
 import language.experimental.captureChecking
-import caps.unbox
 
 class Box[T](items: Seq[T^]):
   def getOne: T^{items*} = ???
 
 object Box:
-  def getOne[T](@unbox items: Seq[T^]): T^{items*} =
+  def getOne[T](items: Seq[T^]): T^{items*} =
     val bx = Box(items)
     bx.getOne
 /*