Fix deep, dark corner of pattern synonyms
authorSimon Peyton Jones <simonpj@microsoft.com>
Thu, 4 Jan 2018 17:18:15 +0000 (17:18 +0000)
committerSimon Peyton Jones <simonpj@microsoft.com>
Thu, 4 Jan 2018 17:24:10 +0000 (17:24 +0000)
commit307d1dfe1d705379eafad6dba65e651ae3465cda
tree93a87a622191dbddf410c07eac3f94229d7a29ac
parent86ea3b1e261ad59dfa7ac13d422a4d657dc83e92
Fix deep, dark corner of pattern synonyms

Trac #14552 showed a very obscure case where we can't infer a
good pattern-synonym type.

The error message is horrible, but at least we no longer crash
and burn.
compiler/typecheck/TcPatSyn.hs
testsuite/tests/patsyn/should_fail/T14552.hs [new file with mode: 0644]
testsuite/tests/patsyn/should_fail/T14552.stderr [new file with mode: 0644]
testsuite/tests/patsyn/should_fail/all.T