diff options
author | Paul Phillips <paulp@improving.org> | 2013-10-01 20:28:48 -0700 |
---|---|---|
committer | Paul Phillips <paulp@improving.org> | 2013-10-01 20:41:41 -0700 |
commit | 5708e9d73ba01c286d7155606b72caeab914face (patch) | |
tree | 422ca2158adb3392aa3826ea9ab9cae4a379f5ce /test/files/neg/run-gadts-strict.scala | |
parent | 95d5554b9a263e3eb060c181463234f3e79864ab (diff) | |
download | scala-5708e9d73ba01c286d7155606b72caeab914face.tar.gz scala-5708e9d73ba01c286d7155606b72caeab914face.tar.bz2 scala-5708e9d73ba01c286d7155606b72caeab914face.zip |
SI-6680 unsoundness in gadt typing.
Introduces -Xstrict-inference to deal with the significant
gap between soundness and what presently compiles. I'm hopeful
that it's TOO strict, because it finds e.g. 75 errors compiling
immutable/IntMap.scala, but it might be that bad.
Diffstat (limited to 'test/files/neg/run-gadts-strict.scala')
-rw-r--r-- | test/files/neg/run-gadts-strict.scala | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/test/files/neg/run-gadts-strict.scala b/test/files/neg/run-gadts-strict.scala new file mode 100644 index 0000000000..041d10d4bd --- /dev/null +++ b/test/files/neg/run-gadts-strict.scala @@ -0,0 +1,18 @@ +// A copy of run/gadts.scala, which must fail under -Xstrict-inference. +abstract class Term[T] +case class Lit(x: Int) extends Term[Int] +case class Succ(t: Term[Int]) extends Term[Int] +case class IsZero(t: Term[Int]) extends Term[Boolean] +case class If[T](c: Term[Boolean], + t1: Term[T], + t2: Term[T]) extends Term[T] + +object Test extends App { + def eval[T](t: Term[T]): T = t match { + case Lit(n) => n + case Succ(u) => eval(u) + 1 + case IsZero(u) => eval(u) == 0 + case If(c, u1, u2) => eval(if (eval(c)) u1 else u2) + } + println(eval(If(IsZero(Lit(1)), Lit(41), Succ(Lit(41))))) +} |