Improve error reporting for impredicative types
authorSimon Peyton Jones <simonpj@microsoft.com>
Tue, 21 Apr 2015 12:43:46 +0000 (13:43 +0100)
committerSimon Peyton Jones <simonpj@microsoft.com>
Wed, 22 Apr 2015 12:56:17 +0000 (13:56 +0100)
commitc715166f9860635d84e4beaa76bf4e23ab764342
treef9f84096236fa23de3ea926b8050b32167f5626d
parent9d3bd3dca889af558737282ad2509b32ded93e6a
Improve error reporting for impredicative types

Don't suggest -XImpredicativeTypes; and document its flakiness
Fixes Trac #10325
compiler/typecheck/TcErrors.hs
compiler/typecheck/TcValidity.hs
docs/users_guide/glasgow_exts.xml
testsuite/tests/typecheck/should_fail/T10194.stderr
testsuite/tests/typecheck/should_fail/T2538.stderr
testsuite/tests/typecheck/should_fail/T7809.stderr
testsuite/tests/typecheck/should_fail/tcfail127.stderr
testsuite/tests/typecheck/should_fail/tcfail197.stderr