import DsGRHSs ( dsGuarded )
import DsCCall ( dsCCall )
import DsListComp ( dsListComp, dsPArrComp )
-import DsUtils ( mkErrorAppDs, mkStringLit, mkConsExpr, mkNilExpr)
+import DsUtils ( mkErrorAppDs, mkStringLit, mkConsExpr, mkNilExpr,
+ mkCoreTupTy, selectMatchVar,
+ dsReboundNames, lookupReboundName )
+import DsArrows ( dsProcExpr )
import DsMonad
#ifdef GHCI
import DsMeta ( dsBracket, dsReify )
#endif
-import HsSyn ( failureFreePat,
- HsExpr(..), Pat(..), HsLit(..), ArithSeqInfo(..),
+import HsSyn ( HsExpr(..), Pat(..), ArithSeqInfo(..),
Stmt(..), HsMatchContext(..), HsStmtContext(..),
Match(..), HsBinds(..), MonoBinds(..), HsConDetails(..),
+ ReboundNames,
mkSimpleMatch, isDoExpr
)
import TcHsSyn ( TypecheckedHsExpr, TypecheckedHsBinds, TypecheckedStmt, hsPatType )
import TyCon ( tyConDataCons )
import TysWiredIn ( tupleCon, mkTupleTy )
import BasicTypes ( RecFlag(..), Boxity(..), ipNameName )
-import PrelNames ( toPName )
+import PrelNames ( toPName,
+ returnMName, bindMName, thenMName, failMName,
+ mfixName )
import SrcLoc ( noSrcLoc )
import Util ( zipEqual, zipWithEqual )
import Outputable
= dsLet b2 body `thenDs` \ body' ->
dsLet b1 body'
+dsLet (IPBinds binds is_with) body
+ = foldlDs dsIPBind body binds
+ where
+ dsIPBind body (n, e)
+ = dsExpr e `thenDs` \ e' ->
+ returnDs (Let (NonRec (ipNameName n) e') body)
+
-- Special case for bindings which bind unlifted variables
-- We need to do a case right away, rather than building
-- a tuple and doing selections.
getModuleDs `thenDs` \ mod_name ->
returnDs (Note (SCC (mkUserCC cc mod_name)) core_expr)
+
+-- hdaume: core annotation
+
+dsExpr (HsCoreAnn fs expr)
+ = dsExpr expr `thenDs` \ core_expr ->
+ returnDs (Note (CoreNote $ unpackFS fs) core_expr)
+
-- special case to handle unboxed tuple patterns.
dsExpr (HsCase discrim matches src_loc)
= dsExpr body `thenDs` \ body' ->
dsLet binds body'
-dsExpr (HsWith expr binds is_with)
- = dsExpr expr `thenDs` \ expr' ->
- foldlDs dsIPBind expr' binds
- where
- dsIPBind body (n, e)
- = dsExpr e `thenDs` \ e' ->
- returnDs (Let (NonRec (ipNameName n) e') body)
-
-- We need the `ListComp' form to use `deListComp' (rather than the "do" form)
-- because the interpretation of `stmts' depends on what sort of thing it is.
--
dsExpr (HsSplice n e _) = pprPanic "dsExpr:splice" (ppr e)
#endif
+-- Arrow notation extension
+dsExpr (HsProc pat cmd src_loc) = dsProcExpr pat cmd src_loc
\end{code}
\begin{code}
dsDo :: HsStmtContext Name
-> [TypecheckedStmt]
- -> [Id] -- id for: [return,fail,>>=,>>] and possibly mfixName
- -> Type -- Element type; the whole expression has type (m t)
+ -> ReboundNames Id -- id for: [return,fail,>>=,>>] and possibly mfixName
+ -> Type -- Element type; the whole expression has type (m t)
-> DsM CoreExpr
dsDo do_or_lc stmts ids result_ty
- = let
- (return_id : fail_id : bind_id : then_id : _) = ids
+ = dsReboundNames ids `thenDs` \ (meth_binds, ds_meths) ->
+ let
+ return_id = lookupReboundName ds_meths returnMName
+ fail_id = lookupReboundName ds_meths failMName
+ bind_id = lookupReboundName ds_meths bindMName
+ then_id = lookupReboundName ds_meths thenMName
+
(m_ty, b_ty) = tcSplitAppTy result_ty -- result_ty must be of the form (m b)
is_do = isDoExpr do_or_lc -- True for both MDo and Do
go [ResultStmt expr locn]
| is_do = do_expr expr locn
| otherwise = do_expr expr locn `thenDs` \ expr2 ->
- returnDs (mkApps (Var return_id) [Type b_ty, expr2])
+ returnDs (mkApps return_id [Type b_ty, expr2])
go (ExprStmt expr a_ty locn : stmts)
| is_do -- Do expression
= do_expr expr locn `thenDs` \ expr2 ->
go stmts `thenDs` \ rest ->
- returnDs (mkApps (Var then_id) [Type a_ty, Type b_ty, expr2, rest])
+ returnDs (mkApps then_id [Type a_ty, Type b_ty, expr2, rest])
| otherwise -- List comprehension
= do_expr expr locn `thenDs` \ expr2 ->
in
mkStringLit msg `thenDs` \ core_msg ->
returnDs (mkIfThenElse expr2 rest
- (App (App (Var fail_id) (Type b_ty)) core_msg))
+ (App (App fail_id (Type b_ty)) core_msg))
- go (LetStmt binds : stmts )
+ go (LetStmt binds : stmts)
= go stmts `thenDs` \ rest ->
dsLet binds rest
go (BindStmt pat expr locn : stmts)
- = putSrcLocDs locn $
- dsExpr expr `thenDs` \ expr2 ->
+ = go stmts `thenDs` \ body ->
+ putSrcLocDs locn $ -- Rest is associated with this location
+ dsExpr expr `thenDs` \ rhs ->
+ mkStringLit (mk_msg locn) `thenDs` \ core_msg ->
let
+ -- In a do expression, pattern-match failure just calls
+ -- the monadic 'fail' rather than throwing an exception
+ fail_expr = mkApps fail_id [Type b_ty, core_msg]
a_ty = hsPatType pat
- fail_expr = HsApp (TyApp (HsVar fail_id) [b_ty])
- (HsLit (HsString (mkFastString msg)))
- msg = "Pattern match failure in do expression, " ++ showSDoc (ppr locn)
- main_match = mkSimpleMatch [pat]
- (HsDo do_or_lc stmts ids result_ty locn)
- result_ty locn
- the_matches
- | failureFreePat pat = [main_match]
- | otherwise =
- [ main_match
- , mkSimpleMatch [WildPat a_ty] fail_expr result_ty locn
- ]
in
- matchWrapper (StmtCtxt do_or_lc) the_matches `thenDs` \ (binders, matching_code) ->
- returnDs (mkApps (Var bind_id) [Type a_ty, Type b_ty, expr2,
- mkLams binders matching_code])
+ selectMatchVar pat `thenDs` \ var ->
+ matchSimply (Var var) (StmtCtxt do_or_lc) pat
+ body fail_expr `thenDs` \ match_code ->
+ returnDs (mkApps bind_id [Type a_ty, Type b_ty, rhs, Lam var match_code])
- go (RecStmt rec_vars rec_stmts rec_rets : stmts)
+ go (RecStmt rec_stmts later_vars rec_vars rec_rets : stmts)
= go (bind_stmt : stmts)
where
- bind_stmt = dsRecStmt m_ty ids rec_vars rec_stmts rec_rets
+ bind_stmt = dsRecStmt m_ty ds_meths rec_stmts later_vars rec_vars rec_rets
in
- go stmts
+ go stmts `thenDs` \ stmts_code ->
+ returnDs (foldr Let stmts_code meth_binds)
where
do_expr expr locn = putSrcLocDs locn (dsExpr expr)
+ mk_msg locn = "Pattern match failure in do expression at " ++ showSDoc (ppr locn)
\end{code}
Translation for RecStmt's:
\begin{code}
dsRecStmt :: Type -- Monad type constructor :: * -> *
- -> [Id] -- Ids for: [return,fail,>>=,>>,mfix]
- -> [Id] -> [TypecheckedStmt] -> [TypecheckedHsExpr] -- Guts of the RecStmt
+ -> [(Name,Id)] -- Rebound Ids
+ -> [TypecheckedStmt]
+ -> [Id] -> [Id] -> [TypecheckedHsExpr]
-> TypecheckedStmt
-dsRecStmt m_ty ids@[return_id, _, _, _, mfix_id] vars stmts rets
+dsRecStmt m_ty ds_meths stmts later_vars rec_vars rec_rets
= ASSERT( length vars == length rets )
BindStmt tup_pat mfix_app noSrcLoc
where
- (var1:rest) = vars -- Always at least one
- (ret1:_) = rets
- one_var = null rest
+ vars@(var1:rest) = later_vars ++ rec_vars -- Always at least one
+ rets@(ret1:_) = map HsVar later_vars ++ rec_rets
+ one_var = null rest
mfix_app = HsApp (TyApp (HsVar mfix_id) [tup_ty]) mfix_arg
mfix_arg = HsLam (mkSimpleMatch [tup_pat] body tup_ty noSrcLoc)
tup_expr | one_var = ret1
| otherwise = ExplicitTuple rets Boxed
- tup_ty | one_var = idType var1
- | otherwise = mkTupleTy Boxed (length vars) (map idType vars)
+ tup_ty = mkCoreTupTy (map idType vars)
+ -- Deals with singleton case
tup_pat | one_var = VarPat var1
| otherwise = LazyPat (TuplePat (map VarPat vars) Boxed)
body = HsDo DoExpr (stmts ++ [return_stmt])
- ids -- Don't need the mfix, but it does no harm
+ [(n, HsVar id) | (n,id) <- ds_meths] -- A bit of a hack
(mkAppTy m_ty tup_ty)
noSrcLoc
+ Var return_id = lookupReboundName ds_meths returnMName
+ Var mfix_id = lookupReboundName ds_meths mfixName
+
return_stmt = ResultStmt return_app noSrcLoc
return_app = HsApp (TyApp (HsVar return_id) [tup_ty]) tup_expr
\end{code}
projects / ghc-hetmet.git / blobdiff