Fix #12176 by being a bit more careful instantiating.
authorRichard Eisenberg <rae@cs.brynmawr.edu>
Tue, 18 Jul 2017 23:44:17 +0000 (19:44 -0400)
committerRichard Eisenberg <rae@cs.brynmawr.edu>
Thu, 27 Jul 2017 11:49:06 +0000 (07:49 -0400)
commit1696dbf4ad0fda4d7c5b4afe1911cab51d7dd0b0
tree8e127bcc981e23184e36c871ad7d40c80dfbc7bc
parentca471860494484210b6291dd96d1e0868da750e7
Fix #12176 by being a bit more careful instantiating.

Previously, looking up a TyCon that said "no" to mightBeUnsaturated
would then instantiate all of its invisible binders. But this is
wrong for vanilla type synonyms, whose RHS kind might legitimately
start with invisible binders. So a little more care is taken now,
only to instantiate those invisible binders that need to be (so that
the TyCon isn't unsaturated).
compiler/typecheck/TcCanonical.hs
compiler/typecheck/TcHsType.hs
testsuite/tests/dependent/should_compile/T12176.hs [new file with mode: 0644]
testsuite/tests/dependent/should_compile/all.T