diff options
| author | Ryan Scott <ryan.gl.scott@gmail.com> | 2018-10-15 13:49:11 -0400 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2018-10-15 17:59:20 -0400 |
| commit | 02b2116e458357e87718e7378a80579a7021e2a7 (patch) | |
| tree | 1849ba48aa90364997602ea5e8a175ef819bc9fa /libraries | |
| parent | c5b477c29127d8375b3f23d37f877278b52547f6 (diff) | |
| download | haskell-02b2116e458357e87718e7378a80579a7021e2a7.tar.gz | |
Fix #15738 by defining (and using) parenthesizeHsContext
With `QuantifiedConstraints`, `forall`s can appear in more
nested positions than they could before, but `Convert` and the TH
pretty-printer were failing to take this into account. On the
`Convert` side, this is fixed by using a `parenthesizeHsContext`
to parenthesize singleton quantified constraints that appear to the
left of a `=>`. (A similar fix is applied to the TH pretty-printer.)
Test Plan: make test TEST=T15738
Reviewers: goldfire, bgamari
Reviewed By: bgamari
Subscribers: rwbarton, carter
GHC Trac Issues: #15738
Differential Revision: https://phabricator.haskell.org/D5222
Diffstat (limited to 'libraries')
| -rw-r--r-- | libraries/template-haskell/Language/Haskell/TH/Ppr.hs | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/libraries/template-haskell/Language/Haskell/TH/Ppr.hs b/libraries/template-haskell/Language/Haskell/TH/Ppr.hs index 8158af6ffd..7df8c98643 100644 --- a/libraries/template-haskell/Language/Haskell/TH/Ppr.hs +++ b/libraries/template-haskell/Language/Haskell/TH/Ppr.hs @@ -795,6 +795,7 @@ pprCxt ts = ppr_cxt_preds ts <+> text "=>" ppr_cxt_preds :: Cxt -> Doc ppr_cxt_preds [] = empty ppr_cxt_preds [t@ImplicitParamT{}] = parens (ppr t) +ppr_cxt_preds [t@ForallT{}] = parens (ppr t) ppr_cxt_preds [t] = ppr t ppr_cxt_preds ts = parens (commaSep ts) |