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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2013-11-25 16:58:28 +0000 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2013-11-25 16:58:43 +0000 |
| commit | 51deeb0db3abac9f4369d3f8a3744e1313ecebf4 (patch) | |
| tree | fde7b556b53bdbf5f6f0adaecdd14e723acb27af /compiler/parser | |
| parent | f8b25c30fe593a1195a4f4840b8773595dd0f2e0 (diff) | |
| download | haskell-51deeb0db3abac9f4369d3f8a3744e1313ecebf4.tar.gz | |
Another raft of Template Haskell clean-up
The handling of typed and untyped brackets was extremely convoluted,
partly because of the evolutionary history. I've tidied it all up.
See Note [How brackets and nested splices are handled] in TcSplice
for the full story
Main changes:
* Untyped brackets: after the renamer, HsRnBracketOut carries
PendingRnSplices for splices in untyped brackets. In the
typechecker, these pending splices are typechecked quite
straigtforwardly, with no ps_var nonsense.
* Typed brackets: after the renamer typed brackest still look
like HsBracket. The type checker does the ps_var thing.
* In TcRnTypes.ThStage, the Brack constructor, we distinguish
the renaming from typehecking pending-stuff. Much more
perspicuous!
* The "typed" flag is in HsSpliceE, not in HsSplice, because
only expressions can be typed. Patterns, types, declarations
cannot.
There is further improvement to be done to make the handling of
declaration splices more uniform.
Diffstat (limited to 'compiler/parser')
| -rw-r--r-- | compiler/parser/RdrHsSyn.lhs | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/compiler/parser/RdrHsSyn.lhs b/compiler/parser/RdrHsSyn.lhs index 46a694b42b..79e53b26ae 100644 --- a/compiler/parser/RdrHsSyn.lhs +++ b/compiler/parser/RdrHsSyn.lhs @@ -1,4 +1,4 @@ -% +o% % (c) The University of Glasgow, 1996-2003 Functions over HsSyn specialised to RdrName. @@ -235,11 +235,13 @@ mkSpliceDecl :: LHsExpr RdrName -> HsDecl RdrName -- but if she wrote, say, -- f x then behave as if she'd written $(f x) -- ie a SpliceD -mkSpliceDecl (L _ (HsQuasiQuoteE qq)) = QuasiQuoteD qq -mkSpliceDecl (L loc (HsSpliceE splice)) = SpliceD (SpliceDecl (L loc splice) Explicit) -mkSpliceDecl other_expr = SpliceD (SpliceDecl (L (getLoc other_expr) splice) Implicit) +mkSpliceDecl lexpr@(L loc expr) + | HsQuasiQuoteE qq <- expr = QuasiQuoteD qq + | HsSpliceE is_typed splice <- expr = ASSERT( not is_typed ) + SpliceD (SpliceDecl (L loc splice) Explicit) + | otherwise = SpliceD (SpliceDecl (L loc splice) Implicit) where - HsSpliceE splice = mkHsSpliceE other_expr + splice = mkHsSplice lexpr mkTyLit :: Located (HsTyLit) -> P (LHsType RdrName) mkTyLit l = @@ -675,11 +677,12 @@ checkAPat msg loc e0 = do | otherwise -> parseErrorSDoc loc (text "Illegal tuple section in pattern:" $$ ppr e0) RecordCon c _ (HsRecFields fs dd) - -> do fs <- mapM (checkPatField msg) fs - return (ConPatIn c (RecCon (HsRecFields fs dd))) - HsSpliceE s -> return (SplicePat s) - HsQuasiQuoteE q -> return (QuasiQuotePat q) - _ -> patFail msg loc e0 + -> do fs <- mapM (checkPatField msg) fs + return (ConPatIn c (RecCon (HsRecFields fs dd))) + HsSpliceE is_typed s | not is_typed + -> return (SplicePat s) + HsQuasiQuoteE q -> return (QuasiQuotePat q) + _ -> patFail msg loc e0 placeHolderPunRhs :: LHsExpr RdrName -- The RHS of a punned record field will be filled in by the renamer |