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| author | Merijn Verstraaten <merijn@inconsistent.nl> | 2014-11-21 15:32:38 -0600 |
|---|---|---|
| committer | Austin Seipp <austin@well-typed.com> | 2014-11-21 17:04:57 -0600 |
| commit | 2cc854b7133e38c7ad1107057931761782d03594 (patch) | |
| tree | 399b3ccdcc7c43dce2e598d1ea42e72ff818000c /compiler/rename/RnExpr.lhs | |
| parent | 624a7c5a2eee0c0ba486a45550680052c2c79849 (diff) | |
| download | haskell-2cc854b7133e38c7ad1107057931761782d03594.tar.gz | |
Add -fdefer-typed-holes flag which defers hole errors to runtime.
Summary:
As proposed by Richard on Trac. This patch adds a new flag -fdefer-typed-holes
and changes the semantics of the -fno-warn-typed-holes flag.
To summarise, by default GHC has typed holes enabled and produces a compile
error when it encounters a typed hole.
When -fdefer-type-errors OR -fdefer-typed-holes is enabled, hole errors are
converted to warnings and result in runtime errors when evaluated.
The warning flag -fwarn-typed-holes is on by default. Without -fdefer-type-errors
or -fdefer-typed-holes this flag is a no-op, since typed holes are an error
under these conditions. If either of the defer flags are enabled (converting
typed hole errors into warnings) the -fno-warn-typed-holes flag disables the
warnings. This means compilation silently succeeds and evaluating a hole will
produce a runtime error.
The rationale behind allowing typed holes warnings to be silenced is that tools
like Syntastic for vim highlight warnings and hole warnings may be undesirable.
Signed-off-by: Merijn Verstraaten <merijn@inconsistent.nl>
Test Plan: validate
Reviewers: austin, simonpj, thomie
Reviewed By: simonpj, thomie
Subscribers: Fuuzetsu, thomie, carter
Differential Revision: https://phabricator.haskell.org/D442
GHC Trac Issues: #9497
Conflicts:
compiler/main/DynFlags.hs
Diffstat (limited to 'compiler/rename/RnExpr.lhs')
| -rw-r--r-- | compiler/rename/RnExpr.lhs | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/compiler/rename/RnExpr.lhs b/compiler/rename/RnExpr.lhs index 30e7112f12..7ef815ff29 100644 --- a/compiler/rename/RnExpr.lhs +++ b/compiler/rename/RnExpr.lhs @@ -88,8 +88,7 @@ finishHsVar name rnExpr (HsVar v) = do { mb_name <- lookupOccRn_maybe v ; case mb_name of { - Nothing -> do { opt_TypeHoles <- woptM Opt_WarnTypedHoles - ; if opt_TypeHoles && startsWithUnderscore (rdrNameOcc v) + Nothing -> do { if startsWithUnderscore (rdrNameOcc v) then return (HsUnboundVar v, emptyFVs) else do { n <- reportUnboundName v; finishHsVar n } } ; Just name @@ -300,11 +299,7 @@ Since all the symbols are reservedops we can simply reject them. We return a (bogus) EWildPat in each case. \begin{code} -rnExpr e@EWildPat = do { holes <- woptM Opt_WarnTypedHoles - ; if holes - then return (hsHoleExpr, emptyFVs) - else patSynErr e - } +rnExpr EWildPat = return (hsHoleExpr, emptyFVs) rnExpr e@(EAsPat {}) = patSynErr e rnExpr e@(EViewPat {}) = patSynErr e rnExpr e@(ELazyPat {}) = patSynErr e |