[commit: ghc] wip/type-app: Allow @_ to be used without fuss (2d2d3a9)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : wip/type-app
Link       : http://ghc.haskell.org/trac/ghc/changeset/2d2d3a906d4c67018579f583d2e174aca8eab21a/ghc

>---------------------------------------------------------------

commit 2d2d3a906d4c67018579f583d2e174aca8eab21a
Author: Richard Eisenberg <eir at cis.upenn.edu>
Date:   Thu Aug 6 11:39:57 2015 -0400

    Allow @_ to be used without fuss


>---------------------------------------------------------------

2d2d3a906d4c67018579f583d2e174aca8eab21a
 compiler/typecheck/TcHsType.hs                   | 7 +++----
 testsuite/tests/typecheck/should_compile/Vta1.hs | 3 +--
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/compiler/typecheck/TcHsType.hs b/compiler/typecheck/TcHsType.hs
index 6dea9e3..1b181af 100644
--- a/compiler/typecheck/TcHsType.hs
+++ b/compiler/typecheck/TcHsType.hs
@@ -237,12 +237,11 @@ tcHsTypeApp (hs_ty, wcs) kind
   = do { nwc_tvs <- mapM newWildcardVarMetaKind wcs
        ; tcExtendTyVarEnv nwc_tvs $
     do { ty <- tcCheckLHsType hs_ty kind
-
-       ; addErrCtxt (pprSigCtxt TypeAppCtxt empty (ppr hs_ty)) $
-         emitWildcardHoleConstraints (zip wcs nwc_tvs)
-
        ; checkValidType TypeAppCtxt ty
        ; return ty } }
+        -- NB: we don't call emitWildcardHoleConstraints here, because
+        -- we want any holes in visible type applications to be used
+        -- without fuss. No errors, warnings, extensions, etc.
 
 {-
         These functions are used during knot-tying in
diff --git a/testsuite/tests/typecheck/should_compile/Vta1.hs b/testsuite/tests/typecheck/should_compile/Vta1.hs
index cb70916..c3ba43d 100644
--- a/testsuite/tests/typecheck/should_compile/Vta1.hs
+++ b/testsuite/tests/typecheck/should_compile/Vta1.hs
@@ -1,7 +1,6 @@
 {-# LANGUAGE TypeApplications, ScopedTypeVariables, PolyKinds,
-             TypeFamilies, RankNTypes, PartialTypeSignatures,
+             TypeFamilies, RankNTypes,
              FlexibleContexts #-}
-{-# OPTIONS_GHC -fno-warn-partial-type-signatures #-}
 -- tests about visible type application
 
 module Vta1 where