Document the kind generalization behavior observed in #13555
authorRyan Scott <ryan.gl.scott@gmail.com>
Sun, 23 Apr 2017 14:02:45 +0000 (10:02 -0400)
committerBen Gamari <ben@smart-cactus.org>
Sun, 23 Apr 2017 15:05:48 +0000 (11:05 -0400)
commit18c3a7ea0f7577514721feadefd9a62c228edb60
tree30165cb428bccd25f5166fc1655d200f6c4a5712
parent9eea43f9528a49194c25889bbfe3b49fe189cc6f
Document the kind generalization behavior observed in #13555

The conclusion of #13555 was that a program which began to fail to
typecheck (starting in GHC 8.2) was never correct to begin with. Let's
document why this is the case with respect to `MonoLocalBinds`'
interaction with kind generalization. Also adds the reported program as
a `compile_fail` testcase.

Test Plan: make test TEST=T13555 # Also, read the docs

Reviewers: goldfire, simonpj, austin, bgamari

Reviewed By: goldfire, simonpj, bgamari

Subscribers: rwbarton, thomie

GHC Trac Issues: #13555

Differential Revision: https://phabricator.haskell.org/D3472
docs/users_guide/8.2.1-notes.rst
docs/users_guide/glasgow_exts.rst
testsuite/tests/polykinds/T13555.hs [new file with mode: 0644]
testsuite/tests/polykinds/T13555.stderr [new file with mode: 0644]
testsuite/tests/polykinds/all.T