diff options
Diffstat (limited to 'test/files/run/macro-range/Expansion_Impossible_2.scala')
| -rw-r--r-- | test/files/run/macro-range/Expansion_Impossible_2.scala | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/test/files/run/macro-range/Expansion_Impossible_2.scala b/test/files/run/macro-range/Expansion_Impossible_2.scala new file mode 100644 index 0000000000..7a093b74ee --- /dev/null +++ b/test/files/run/macro-range/Expansion_Impossible_2.scala @@ -0,0 +1,53 @@ +import reflect.api.Modifier +import reflect.makro.Context + +object Impls { + def foreach(c: Context)(f: c.Expr[Int => Unit]): c.Expr[Unit] = { + // todo. read the compiler config and print if -Ydebug is set + //println("macro-expand, _this = "+ _this) + object utils extends Utils { val context: c.type = c } + import utils._ + import c.mirror._ + + val initName = newTermName("<init>") + // Either: + // scala"{ var i = $low; val h = $hi; while (i < h) { $f(i); i = i + 1 } } + // or: + // scala"($_this: RangeDefault).foreach($f)" + c.prefix.tree match { + case Apply(Select(New(tpt), initName), List(lo, hi)) if tpt.symbol.fullName == "Range" => + val iname = newTermName("$i") + val hname = newTermName("$h") + def iref = Ident(iname) + def href = Ident(hname) + val labelname = newTermName("$while") + val cond = makeBinop(iref, "$less", href) + val body = Block( + List(makeApply(f, List(iref))), + Assign(iref, makeBinop(iref, "$plus", Literal(Constant(1))))) + val generated = + Block( + List( + ValDef(Modifiers(Set(Modifier.mutable)), iname, TypeTree(), lo), + ValDef(Modifiers(), hname, TypeTree(), hi)), + makeWhile(labelname, cond, body)) + // todo. read the compiler config and print if -Ydebug is set + //tools.nsc.util.trace("generated: ")(generated) + generated + case _ => + Apply( + Select( + Typed(c.prefix, Ident(newTypeName("RangeDefault"))), + newTermName("foreach")), + List(f)) + } + } +} + +class Range(val from: Int, val to: Int) extends RangeDefault { + override def foreach(f: Int => Unit): Unit = macro Impls.foreach +} + +object Test extends App { + new Range(1, 10) foreach println +}
\ No newline at end of file |