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author | Adriaan Moors <adriaan.moors@epfl.ch> | 2010-09-16 22:26:24 +0000 |
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committer | Adriaan Moors <adriaan.moors@epfl.ch> | 2010-09-16 22:26:24 +0000 |
commit | e557acb9a7d672c0635c3eaf9fe385adc41e5c86 (patch) | |
tree | d13db6639464acc57f0e44b4b3ef6f3e607ad403 /test/files/pos/depmet_implicit_chaining_zw.scala | |
parent | ce223fe7abc47af712382a64404604e75f9f4d20 (diff) | |
download | scala-e557acb9a7d672c0635c3eaf9fe385adc41e5c86.tar.gz scala-e557acb9a7d672c0635c3eaf9fe385adc41e5c86.tar.bz2 scala-e557acb9a7d672c0635c3eaf9fe385adc41e5c86.zip |
part 2 of the dependent method refactoring: imp...
part 2 of the dependent method refactoring: improved interaction with
implicit search (needed for oopsla paper)
more to come in this area, see e.g. #3346 (stanford edsl stuff)
reopens #13, which wasn't fixed properly before imo, anyway (have a look at -Xprint:typer output before this commit: a type that's not expressible in surface syntax is inferred -- also removed duplicate test file)
closes #3731: co-evolve type alias type symbols when their rhs is
updated and they are referenced by type selections (see typemap)
review by odersky
Diffstat (limited to 'test/files/pos/depmet_implicit_chaining_zw.scala')
-rw-r--r-- | test/files/pos/depmet_implicit_chaining_zw.scala | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/test/files/pos/depmet_implicit_chaining_zw.scala b/test/files/pos/depmet_implicit_chaining_zw.scala new file mode 100644 index 0000000000..e3a145ab38 --- /dev/null +++ b/test/files/pos/depmet_implicit_chaining_zw.scala @@ -0,0 +1,28 @@ +trait Zero +trait Succ[N] + +trait ZipWith[N, S] { + type T + val x: T = error("") +} + +object ZipWith { + implicit def ZeroZipWith[S] = new ZipWith[Zero, S] { + type T = Stream[S] + } + + implicit def SuccZipWith[N, S, R](implicit zWith : ZipWith[N, R]) = new ZipWith[Succ[N], S => R] { + type T = Stream[S] => zWith.T // dependent types replace the associated types functionality + } + + // can't use implicitly[ZipWith[Succ[Succ[Zero]], Int => String => Boolean]], + // since that will chop of the {type T = ... } refinement in adapt (pt = ZipWith[Succ[Succ[Zero]], Int => String => Boolean]) + // this works + // def zipWith(implicit zw: ZipWith[Succ[Succ[Zero]], Int => String => Boolean]): zw.T = zw.x + // thus, I present ?: implicitly on steroids! + def ?[T <: AnyRef](implicit w: T): w.type = w + + type _2 = Succ[Succ[Zero]] + val zw = ?[ZipWith[_2, Int => String => Boolean]].x // : Stream[Int] => Stream[String] => Stream[Boolean] + // val zw = implicitly[ZipWith[Succ[Succ[Zero]], Int => String => Boolean]{type T = Stream[Int] => Stream[String] => Stream[Boolean]}].x +}
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