Do not unify representational equalities
authorSimon Peyton Jones <simonpj@microsoft.com>
Fri, 18 May 2018 12:58:25 +0000 (13:58 +0100)
committerSimon Peyton Jones <simonpj@microsoft.com>
Fri, 18 May 2018 16:18:47 +0000 (17:18 +0100)
commitae292c6d1362f34117be75a2553049cec7022244
treef15df094b13a920a183ef4b5a9d09e79e495990c
parent5a7c657e02b1e801c84f26ea383f326234cd993c
Do not unify representational equalities

This patch is an easy fix to Trac #15144, which was caused
by accidentally unifying a representational equality in the
unflattener.  (The main code in TcInteract was always careful
not to do so, but I'd missed the test in the unflattener.)

See Note [Do not unify representational equalities]
in TcInteract
compiler/typecheck/TcFlatten.hs
compiler/typecheck/TcInteract.hs
testsuite/tests/indexed-types/should_compile/T15144.hs [new file with mode: 0644]
testsuite/tests/indexed-types/should_compile/all.T