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author | Martin Odersky <odersky@gmail.com> | 2014-06-20 15:04:03 +0200 |
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committer | Martin Odersky <odersky@gmail.com> | 2014-06-20 15:04:19 +0200 |
commit | b3364db33ff2ee2d57b4d0eaed03632099244f63 (patch) | |
tree | cfc94722c01bf6a7ddb3eff5411149e8a40235e1 /tests/pos | |
parent | 7cf6202ea94c016ffc2d2528ad8add186e9f3827 (diff) | |
download | dotty-b3364db33ff2ee2d57b4d0eaed03632099244f63.tar.gz dotty-b3364db33ff2ee2d57b4d0eaed03632099244f63.tar.bz2 dotty-b3364db33ff2ee2d57b4d0eaed03632099244f63.zip |
Avoid caching values that depend on typevar state.
TypeVars flip from the initial state, where underlying == origin to the final state
where underlying == inst. This flip can invalidate information that depends on the underlying
type of a TypeVar. Since we do not know when the flip occurs, we need to avoid keeping
any such information in a cache.
The commit makes three caches depend on a new value: typerState.ephemeral. The value is
set to `true` each time we follow the underlying type of a TypeVar, and this disables cached
information to be retained.
A test case for this commit is t2693.scala. This test passes typechecking with the previous commit,
but fails in -Ycheck:front because of stale cache info in an "#Apply" typeref. The present commit fixes that.
Diffstat (limited to 'tests/pos')
-rw-r--r-- | tests/pos/t2693.scala | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/tests/pos/t2693.scala b/tests/pos/t2693.scala new file mode 100644 index 000000000..5d4d0380c --- /dev/null +++ b/tests/pos/t2693.scala @@ -0,0 +1,6 @@ +class A { + trait T[A] + def usetHk[T[_], A](ta: T[A]) = 0 + usetHk(new T[Int]{}: T[Int]) + usetHk(new T[Int]{}) // fails with: found: java.lang.Object with T[Int], required: ?T[ ?A ] +} |