diff options
Diffstat (limited to 'tests/disabled/macro/run/macro-whitebox-fundep-materialization/Macros_1.scala')
-rw-r--r-- | tests/disabled/macro/run/macro-whitebox-fundep-materialization/Macros_1.scala | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/tests/disabled/macro/run/macro-whitebox-fundep-materialization/Macros_1.scala b/tests/disabled/macro/run/macro-whitebox-fundep-materialization/Macros_1.scala new file mode 100644 index 000000000..5e89e6b2f --- /dev/null +++ b/tests/disabled/macro/run/macro-whitebox-fundep-materialization/Macros_1.scala @@ -0,0 +1,39 @@ +import scala.language.experimental.macros +import scala.reflect.macros.whitebox.Context + +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: Context): 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"$sym is not a case class") + val fields = sym.info.decls.toList.collect{ case x: TermSymbol if x.isVal && x.isCaseAccessor => x } + + def mkTpt() = { + val core = Ident(TupleClass(fields.length) orElse UnitClass) + if (fields.length == 0) core + else AppliedTypeTree(core, fields map (f => TypeTree(f.info))) + } + + def mkFrom() = { + if (fields.length == 0) Literal(Constant(Unit)) + else Apply(Ident(newTermName("Tuple" + fields.length)), fields map (f => Select(Ident(newTermName("f")), newTermName(f.name.toString.trim)))) + } + + val evidenceClass = ClassDef(Modifiers(FINAL), newTypeName("$anon"), List(), Template( + List(AppliedTypeTree(Ident(newTypeName("Iso")), List(Ident(sym), mkTpt()))), + emptyValDef, + List( + DefDef(Modifiers(), termNames.CONSTRUCTOR, List(), List(List()), TypeTree(), Block(List(Apply(Select(Super(This(typeNames.EMPTY), typeNames.EMPTY), termNames.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"))), termNames.CONSTRUCTOR), List()))) + } +} |