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| author | Eugene Burmako <xeno.by@gmail.com> | 2013-10-02 17:21:55 +0200 |
|---|---|---|
| committer | Adriaan Moors <adriaan.moors@typesafe.com> | 2013-11-12 18:40:01 -0800 |
| commit | 6038bac3513a834e67ab4074c2c7b03aac11b1b3 (patch) | |
| tree | 61a5fb1019fd24e69c8fca420b710f1235b27b50 /test/files/run/t5923c | |
| parent | a2b523a39b4e56eb9ab5d9a5639f5b59d425e354 (diff) | |
| download | scala-6038bac3513a834e67ab4074c2c7b03aac11b1b3.tar.gz scala-6038bac3513a834e67ab4074c2c7b03aac11b1b3.tar.bz2 scala-6038bac3513a834e67ab4074c2c7b03aac11b1b3.zip | |
blackbox restriction #2: can't guide type inference
When an application of a blackbox macro still has undetermined type
parameters after Scala’s type inference algorithm has finished working,
these type parameters are inferred forcedly, in exactly the same manner
as type inference happens for normal methods.
This makes it impossible for blackbox macros to influence type inference,
prohibiting fundep materialization.
Diffstat (limited to 'test/files/run/t5923c')
| -rw-r--r-- | test/files/run/t5923c/Macros_1.scala | 39 | ||||
| -rw-r--r-- | test/files/run/t5923c/Test_2.scala | 12 |
2 files changed, 0 insertions, 51 deletions
diff --git a/test/files/run/t5923c/Macros_1.scala b/test/files/run/t5923c/Macros_1.scala deleted file mode 100644 index c86e14966b..0000000000 --- a/test/files/run/t5923c/Macros_1.scala +++ /dev/null @@ -1,39 +0,0 @@ -import language.experimental.macros -import scala.reflect.macros.WhiteboxContext - -trait Iso[T, U] { - def to(t : T) : U - // def from(u : U) : T -} - -object Iso { - implicit def materializeIso[T, U]: Iso[T, U] = macro impl[T, U] - def impl[T: c.WeakTypeTag, U: c.WeakTypeTag](c: WhiteboxContext): c.Expr[Iso[T, U]] = { - import c.universe._ - import definitions._ - import Flag._ - - val sym = c.weakTypeOf[T].typeSymbol - if (!sym.isClass || !sym.asClass.isCaseClass) c.abort(c.enclosingPosition, s"$sym is not a case class") - val fields = sym.typeSignature.declarations.toList.collect{ case x: TermSymbol if x.isVal && x.isCaseAccessor => x } - - def mkTpt() = { - val core = Ident(TupleClass(fields.length) orElse UnitClass) - if (fields.length == 0) core - else AppliedTypeTree(core, fields map (f => TypeTree(f.typeSignature))) - } - - def mkFrom() = { - if (fields.length == 0) Literal(Constant(Unit)) - else Apply(Ident(newTermName("Tuple" + fields.length)), fields map (f => Select(Ident(newTermName("f")), newTermName(f.name.toString.trim)))) - } - - val evidenceClass = ClassDef(Modifiers(FINAL), newTypeName("$anon"), List(), Template( - List(AppliedTypeTree(Ident(newTypeName("Iso")), List(Ident(sym), mkTpt()))), - emptyValDef, - List( - DefDef(Modifiers(), nme.CONSTRUCTOR, List(), List(List()), TypeTree(), Block(List(Apply(Select(Super(This(tpnme.EMPTY), tpnme.EMPTY), nme.CONSTRUCTOR), List())), Literal(Constant(())))), - DefDef(Modifiers(), newTermName("to"), List(), List(List(ValDef(Modifiers(PARAM), newTermName("f"), Ident(sym), EmptyTree))), TypeTree(), mkFrom())))) - c.Expr[Iso[T, U]](Block(List(evidenceClass), Apply(Select(New(Ident(newTypeName("$anon"))), nme.CONSTRUCTOR), List()))) - } -} diff --git a/test/files/run/t5923c/Test_2.scala b/test/files/run/t5923c/Test_2.scala deleted file mode 100644 index a00f4ed7db..0000000000 --- a/test/files/run/t5923c/Test_2.scala +++ /dev/null @@ -1,12 +0,0 @@ -// see the comments for macroExpandApply.onDelayed for an explanation of what's tested here -object Test extends App { - case class Foo(i: Int, s: String, b: Boolean) - def foo[C, L](c: C)(implicit iso: Iso[C, L]): L = iso.to(c) - - { - val equiv = foo(Foo(23, "foo", true)) - def typed[T](t: => T) {} - typed[(Int, String, Boolean)](equiv) - println(equiv) - } -}
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