import HsSyn ( failureFreePat,
HsExpr(..), OutPat(..), HsLit(..), ArithSeqInfo(..),
- Stmt(..), StmtCtxt(..), Match(..), HsBinds(..), MonoBinds(..),
- mkSimpleMatch
- )
-import TcHsSyn ( TypecheckedHsExpr, TypecheckedHsBinds,
- TypecheckedStmt
+ Stmt(..), HsMatchContext(..), HsDoContext(..),
+ Match(..), HsBinds(..), MonoBinds(..),
+ mkSimpleMatch
)
+import TcHsSyn ( TypecheckedHsExpr, TypecheckedHsBinds, TypecheckedStmt, outPatType )
+
+-- NB: The desugarer, which straddles the source and Core worlds, sometimes
+-- needs to see source types (newtypes etc), and sometimes not
+-- So WATCH OUT; check each use of split*Ty functions.
+-- Sigh. This is a pain.
+
+import TcType ( tcSplitAppTy, tcSplitFunTys, tcTyConAppArgs,
+ isIntegerTy, tcSplitTyConApp, isUnLiftedType, Type )
+import Type ( splitFunTys )
import CoreSyn
import CoreUtils ( exprType, mkIfThenElse, bindNonRec )
import DsBinds ( dsMonoBinds, AutoScc(..) )
import DsGRHSs ( dsGuarded )
import DsCCall ( dsCCall, resultWrapper )
-import DsListComp ( dsListComp )
-import DsUtils ( mkErrorAppDs, mkDsLets, mkStringLit, mkStringLitFS,
+import DsListComp ( dsListComp, dsPArrComp )
+import DsUtils ( mkErrorAppDs, mkStringLit, mkStringLitFS,
mkConsExpr, mkNilExpr, mkIntegerLit
)
import Match ( matchWrapper, matchSimply )
import CostCentre ( mkUserCC )
import Id ( Id, idType, recordSelectorFieldLabel )
import PrelInfo ( rEC_CON_ERROR_ID, iRREFUT_PAT_ERROR_ID )
-import DataCon ( DataCon, dataConWrapId, dataConArgTys, dataConFieldLabels )
+import DataCon ( DataCon, dataConWrapId, dataConFieldLabels, dataConInstOrigArgTys )
import DataCon ( isExistentialDataCon )
import Literal ( Literal(..) )
import TyCon ( tyConDataCons )
-import Type ( splitFunTys,
- splitAlgTyConApp, splitTyConApp_maybe, tyConAppArgs,
- splitAppTy, isUnLiftedType, Type
- )
-import TysWiredIn ( tupleCon, listTyCon, charDataCon, intDataCon, isIntegerTy )
-import BasicTypes ( RecFlag(..), Boxity(..) )
+import TysWiredIn ( tupleCon, charDataCon, intDataCon )
+import BasicTypes ( RecFlag(..), Boxity(..), ipNameName )
import Maybes ( maybeToBool )
-import PrelNames ( hasKey, ratioTyConKey )
+import PrelNames ( hasKey, ratioTyConKey, toPName )
import Util ( zipEqual, zipWithEqual )
import Outputable
dsLet b1 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.
-- Silently ignore INLINE pragmas...
-dsLet (MonoBind (AbsBinds [] [] binder_triples inlines
- (PatMonoBind pat grhss loc)) sigs is_rec) body
- | or [isUnLiftedType (idType g) | (_, g, l) <- binder_triples]
+dsLet bind@(MonoBind (AbsBinds [] [] exports inlines binds) sigs is_rec) body
+ | or [isUnLiftedType (idType g) | (_, g, l) <- exports]
= ASSERT (case is_rec of {NonRecursive -> True; other -> False})
- putSrcLocDs loc $
- dsGuarded grhss `thenDs` \ rhs ->
- let
- body' = foldr bind body binder_triples
- bind (tyvars, g, l) body = ASSERT( null tyvars )
- bindNonRec g (Var l) body
- in
- mkErrorAppDs iRREFUT_PAT_ERROR_ID result_ty (showSDoc (ppr pat))
- `thenDs` \ error_expr ->
- matchSimply rhs PatBindMatch pat body' error_expr
+ -- Unlifted bindings are always non-recursive
+ -- and are always a Fun or Pat monobind
+ --
+ -- ToDo: in some bizarre case it's conceivable that there
+ -- could be dict binds in the 'binds'. (See the notes
+ -- below. Then pattern-match would fail. Urk.)
+ case binds of
+ FunMonoBind fun _ matches loc
+ -> putSrcLocDs loc $
+ matchWrapper (FunRhs fun) matches `thenDs` \ (args, rhs) ->
+ ASSERT( null args ) -- Functions aren't lifted
+ returnDs (bindNonRec fun rhs body_w_exports)
+
+ PatMonoBind pat grhss loc
+ -> putSrcLocDs loc $
+ dsGuarded grhss `thenDs` \ rhs ->
+ mk_error_app pat `thenDs` \ error_expr ->
+ matchSimply rhs PatBindRhs pat body_w_exports error_expr
+
+ other -> pprPanic "dsLet: unlifted" (ppr bind $$ ppr body)
where
- result_ty = exprType body
+ body_w_exports = foldr bind_export body exports
+ bind_export (tvs, g, l) body = ASSERT( null tvs )
+ bindNonRec g (Var l) body
+
+ mk_error_app pat = mkErrorAppDs iRREFUT_PAT_ERROR_ID
+ (exprType body)
+ (showSDoc (ppr pat))
-- Ordinary case for bindings
dsLet (MonoBind binds sigs is_rec) body
= dsMonoBinds NoSccs binds [] `thenDs` \ prs ->
- case is_rec of
- Recursive -> returnDs (Let (Rec prs) body)
- NonRecursive -> returnDs (mkDsLets [NonRec b r | (b,r) <- prs] body)
-\end{code}
+ returnDs (Let (Rec prs) body)
+ -- Use a Rec regardless of is_rec.
+ -- Why? Because it allows the MonoBinds to be all
+ -- mixed up, which is what happens in one rare case
+ -- Namely, for an AbsBind with no tyvars and no dicts,
+ -- but which does have dictionary bindings.
+ -- See notes with TcSimplify.inferLoop [NO TYVARS]
+ -- It turned out that wrapping a Rec here was the easiest solution
+ --
+ -- NB The previous case dealt with unlifted bindings, so we
+ -- only have to deal with lifted ones now; so Rec is ok
+\end{code}
%************************************************************************
%* *
\begin{code}
dsExpr :: TypecheckedHsExpr -> DsM CoreExpr
-dsExpr (HsVar var) = returnDs (Var var)
-dsExpr (HsIPVar var) = returnDs (Var var)
-dsExpr (HsLit lit) = dsLit lit
+dsExpr (HsVar var) = returnDs (Var var)
+dsExpr (HsIPVar ip) = returnDs (Var (ipNameName ip))
+dsExpr (HsLit lit) = dsLit lit
-- HsOverLit has been gotten rid of by the type checker
dsExpr expr@(HsLam a_Match)
- = matchWrapper LambdaMatch [a_Match] "lambda" `thenDs` \ (binders, matching_code) ->
+ = matchWrapper LambdaExpr [a_Match] `thenDs` \ (binders, matching_code) ->
returnDs (mkLams binders matching_code)
dsExpr expr@(HsApp fun arg)
= dsExpr fun `thenDs` \ core_fun ->
dsExpr arg `thenDs` \ core_arg ->
returnDs (core_fun `App` core_arg)
-
\end{code}
Operator sections. At first it looks as if we can convert
-- for the type of y, we need the type of op's 2nd argument
let
(x_ty:y_ty:_, _) = splitFunTys (exprType core_op)
+ -- Must look through an implicit-parameter type;
+ -- newtype impossible; hence Type.splitFunTys
in
dsExpr expr `thenDs` \ x_core ->
newSysLocalDs x_ty `thenDs` \ x_id ->
-- for the type of x, we need the type of op's 2nd argument
let
(x_ty:y_ty:_, _) = splitFunTys (exprType core_op)
+ -- See comment with SectionL
in
dsExpr expr `thenDs` \ y_core ->
newSysLocalDs x_ty `thenDs` \ x_id ->
dsExpr (HsCase discrim matches src_loc)
| all ubx_tuple_match matches
= putSrcLocDs src_loc $
- dsExpr discrim `thenDs` \ core_discrim ->
- matchWrapper CaseMatch matches "case" `thenDs` \ ([discrim_var], matching_code) ->
+ dsExpr discrim `thenDs` \ core_discrim ->
+ matchWrapper CaseAlt matches `thenDs` \ ([discrim_var], matching_code) ->
case matching_code of
Case (Var x) bndr alts | x == discrim_var ->
returnDs (Case core_discrim bndr alts)
_ -> panic ("dsExpr: tuple pattern:\n" ++ showSDoc (ppr matching_code))
where
- ubx_tuple_match (Match _ [TuplePat ps Unboxed] _ _) = True
+ ubx_tuple_match (Match [TuplePat ps Unboxed] _ _) = True
ubx_tuple_match _ = False
dsExpr (HsCase discrim matches src_loc)
= putSrcLocDs src_loc $
- dsExpr discrim `thenDs` \ core_discrim ->
- matchWrapper CaseMatch matches "case" `thenDs` \ ([discrim_var], matching_code) ->
+ dsExpr discrim `thenDs` \ core_discrim ->
+ matchWrapper CaseAlt matches `thenDs` \ ([discrim_var], matching_code) ->
returnDs (bindNonRec discrim_var core_discrim matching_code)
dsExpr (HsLet binds body)
where
dsIPBind body (n, e)
= dsExpr e `thenDs` \ e' ->
- returnDs (Let (NonRec n e') body)
+ returnDs (Let (NonRec (ipNameName n) e') body)
-dsExpr (HsDoOut do_or_lc stmts return_id then_id fail_id result_ty src_loc)
- | maybeToBool maybe_list_comp
+-- 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 (HsDoOut ListComp stmts return_id then_id fail_id result_ty src_loc)
= -- Special case for list comprehensions
putSrcLocDs src_loc $
dsListComp stmts elt_ty
+ where
+ (_, [elt_ty]) = tcSplitTyConApp result_ty
- | otherwise
+dsExpr (HsDoOut DoExpr stmts return_id then_id fail_id result_ty src_loc)
= putSrcLocDs src_loc $
- dsDo do_or_lc stmts return_id then_id fail_id result_ty
+ dsDo DoExpr stmts return_id then_id fail_id result_ty
+
+dsExpr (HsDoOut PArrComp stmts return_id then_id fail_id result_ty src_loc)
+ = -- Special case for array comprehensions
+ putSrcLocDs src_loc $
+ dsPArrComp stmts elt_ty
where
- maybe_list_comp
- = case (do_or_lc, splitTyConApp_maybe result_ty) of
- (ListComp, Just (tycon, [elt_ty]))
- | tycon == listTyCon
- -> Just elt_ty
- other -> Nothing
- -- We need the ListComp form to use deListComp (rather than the "do" form)
- -- because the "return" in a do block is a call to "PrelBase.return", and
- -- not a ReturnStmt. Only the ListComp form has ReturnStmts
-
- Just elt_ty = maybe_list_comp
+ (_, [elt_ty]) = tcSplitTyConApp result_ty
dsExpr (HsIf guard_expr then_expr else_expr src_loc)
= putSrcLocDs src_loc $
\underline{\bf Various data construction things}
% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
-dsExpr (ExplicitListOut ty xs)
+dsExpr (ExplicitList ty xs)
= go xs
where
go [] = returnDs (mkNilExpr ty)
go xs `thenDs` \ core_xs ->
returnDs (mkConsExpr ty core_x core_xs)
+-- we create a list from the array elements and convert them into a list using
+-- `PrelPArr.toP'
+--
+-- * the main disadvantage to this scheme is that `toP' traverses the list
+-- twice: once to determine the length and a second time to put to elements
+-- into the array; this inefficiency could be avoided by exposing some of
+-- the innards of `PrelPArr' to the compiler (ie, have a `PrelPArrBase') so
+-- that we can exploit the fact that we already know the length of the array
+-- here at compile time
+--
+dsExpr (ExplicitPArr ty xs)
+ = dsLookupGlobalValue toPName `thenDs` \toP ->
+ dsExpr (ExplicitList ty xs) `thenDs` \coreList ->
+ returnDs (mkApps (Var toP) [Type ty, coreList])
+
dsExpr (ExplicitTuple expr_list boxity)
= mapDs dsExpr expr_list `thenDs` \ core_exprs ->
returnDs (mkConApp (tupleCon boxity (length expr_list))
dsExpr thn `thenDs` \ thn2 ->
dsExpr two `thenDs` \ two2 ->
returnDs (mkApps expr2 [from2, thn2, two2])
+
+dsExpr (PArrSeqOut expr (FromTo from two))
+ = dsExpr expr `thenDs` \ expr2 ->
+ dsExpr from `thenDs` \ from2 ->
+ dsExpr two `thenDs` \ two2 ->
+ returnDs (mkApps expr2 [from2, two2])
+
+dsExpr (PArrSeqOut expr (FromThenTo from thn two))
+ = dsExpr expr `thenDs` \ expr2 ->
+ dsExpr from `thenDs` \ from2 ->
+ dsExpr thn `thenDs` \ thn2 ->
+ dsExpr two `thenDs` \ two2 ->
+ returnDs (mkApps expr2 [from2, thn2, two2])
+
+dsExpr (PArrSeqOut expr _)
+ = panic "DsExpr.dsExpr: Infinite parallel array!"
+ -- the parser shouldn't have generated it and the renamer and typechecker
+ -- shouldn't have let it through
\end{code}
\noindent
dsExpr (RecordConOut data_con con_expr rbinds)
= dsExpr con_expr `thenDs` \ con_expr' ->
let
- (arg_tys, _) = splitFunTys (exprType con_expr')
+ (arg_tys, _) = tcSplitFunTys (exprType con_expr')
+ -- A newtype in the corner should be opaque;
+ -- hence TcType.tcSplitFunTys
mk_arg (arg_ty, lbl)
= case [rhs | (sel_id,rhs,_) <- rbinds,
dictionaries.
\begin{code}
-dsExpr (RecordUpdOut record_expr record_out_ty dicts [])
+dsExpr (RecordUpdOut record_expr record_in_ty record_out_ty dicts [])
= dsExpr record_expr
-dsExpr (RecordUpdOut record_expr record_out_ty dicts rbinds)
+dsExpr expr@(RecordUpdOut record_expr record_in_ty record_out_ty dicts rbinds)
= getSrcLocDs `thenDs` \ src_loc ->
dsExpr record_expr `thenDs` \ record_expr' ->
-- necessary so that we don't lose sharing
let
- record_in_ty = exprType record_expr'
- in_inst_tys = tyConAppArgs record_in_ty
- out_inst_tys = tyConAppArgs record_out_ty
+ in_inst_tys = tcTyConAppArgs record_in_ty -- Newtype opaque
+ out_inst_tys = tcTyConAppArgs record_out_ty -- Newtype opaque
mk_val_arg field old_arg_id
= case [rhs | (sel_id, rhs, _) <- rbinds,
[] -> HsVar old_arg_id
mk_alt con
- = newSysLocalsDs (dataConArgTys con in_inst_tys) `thenDs` \ arg_ids ->
+ = newSysLocalsDs (dataConInstOrigArgTys con in_inst_tys) `thenDs` \ arg_ids ->
-- This call to dataConArgTys won't work for existentials
let
val_args = zipWithEqual "dsExpr:RecordUpd" mk_val_arg
in
returnDs (mkSimpleMatch [ConPat con record_in_ty [] [] (map VarPat arg_ids)]
rhs
- (Just record_out_ty)
+ record_out_ty
src_loc)
in
-- Record stuff doesn't work for existentials
- ASSERT( all (not . isExistentialDataCon) data_cons )
+ -- The type checker checks for this, but we need
+ -- worry only about the constructors that are to be updated
+ ASSERT2( all (not . isExistentialDataCon) cons_to_upd, ppr expr )
-- It's important to generate the match with matchWrapper,
-- and the right hand sides with applications of the wrapper Id
-- so that everything works when we are doing fancy unboxing on the
-- constructor aguments.
- mapDs mk_alt cons_to_upd `thenDs` \ alts ->
- matchWrapper RecUpdMatch alts "record update" `thenDs` \ ([discrim_var], matching_code) ->
+ mapDs mk_alt cons_to_upd `thenDs` \ alts ->
+ matchWrapper RecUpd alts `thenDs` \ ([discrim_var], matching_code) ->
returnDs (bindNonRec discrim_var record_expr' matching_code)
#ifdef DEBUG
-- HsSyn constructs that just shouldn't be here:
dsExpr (HsDo _ _ _) = panic "dsExpr:HsDo"
-dsExpr (ExplicitList _) = panic "dsExpr:ExplicitList"
dsExpr (ExprWithTySig _ _) = panic "dsExpr:ExprWithTySig"
dsExpr (ArithSeqIn _) = panic "dsExpr:ArithSeqIn"
+dsExpr (PArrSeqIn _) = panic "dsExpr:PArrSeqIn"
#endif
\end{code}
Basically does the translation given in the Haskell~1.3 report:
\begin{code}
-dsDo :: StmtCtxt
+dsDo :: HsDoContext
-> [TypecheckedStmt]
-> Id -- id for: return m
-> Id -- id for: (>>=) m
dsDo do_or_lc stmts return_id then_id fail_id result_ty
= let
- (_, b_ty) = splitAppTy result_ty -- result_ty must be of the form (m b)
+ (_, b_ty) = tcSplitAppTy result_ty -- result_ty must be of the form (m b)
+ is_do = case do_or_lc of
+ DoExpr -> True
+ _ -> False
- go [ReturnStmt expr]
- = dsExpr expr `thenDs` \ expr2 ->
- returnDs (mkApps (Var return_id) [Type b_ty, expr2])
-
- go (GuardStmt expr locn : stmts)
+ -- For ExprStmt, see the comments near HsExpr.Stmt about
+ -- exactly what ExprStmts mean!
+ --
+ -- In dsDo we can only see DoStmt and ListComp (no gaurds)
+
+ 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])
+
+ go (ExprStmt expr a_ty locn : stmts)
+ | is_do -- Do expression
+ = do_expr expr locn `thenDs` \ expr2 ->
+ go stmts `thenDs` \ rest ->
+ newSysLocalDs a_ty `thenDs` \ ignored_result_id ->
+ returnDs (mkApps (Var then_id) [Type a_ty, Type b_ty, expr2,
+ Lam ignored_result_id rest])
+
+ | otherwise -- List comprehension
= do_expr expr locn `thenDs` \ expr2 ->
go stmts `thenDs` \ rest ->
- let msg = "Pattern match failure in do expression, " ++ showSDoc (ppr locn)
- in
- mkStringLit msg `thenDs` \ core_msg ->
- returnDs (mkIfThenElse expr2
- rest
- (App (App (Var fail_id)
- (Type b_ty))
- core_msg))
-
- go (ExprStmt expr locn : stmts)
- = do_expr expr locn `thenDs` \ expr2 ->
let
- (_, a_ty) = splitAppTy (exprType expr2) -- Must be of form (m a)
+ msg = "Pattern match failure in do expression, " ++ showSDoc (ppr locn)
in
- if null stmts then
- returnDs expr2
- else
- go stmts `thenDs` \ rest ->
- newSysLocalDs a_ty `thenDs` \ ignored_result_id ->
- returnDs (mkApps (Var then_id) [Type a_ty, Type b_ty, expr2,
- Lam ignored_result_id rest])
+ mkStringLit msg `thenDs` \ core_msg ->
+ returnDs (mkIfThenElse expr2 rest
+ (App (App (Var fail_id) (Type b_ty)) core_msg))
go (LetStmt binds : stmts )
= go stmts `thenDs` \ rest ->
= putSrcLocDs locn $
dsExpr expr `thenDs` \ expr2 ->
let
- (_, a_ty) = splitAppTy (exprType expr2) -- Must be of form (m a)
+ a_ty = outPatType pat
fail_expr = HsApp (TyApp (HsVar fail_id) [b_ty])
(HsLit (HsString (_PK_ msg)))
msg = "Pattern match failure in do expression, " ++ showSDoc (ppr locn)
main_match = mkSimpleMatch [pat]
(HsDoOut do_or_lc stmts return_id then_id
fail_id result_ty locn)
- (Just result_ty) locn
+ result_ty locn
the_matches
| failureFreePat pat = [main_match]
| otherwise =
[ main_match
- , mkSimpleMatch [WildPat a_ty] fail_expr (Just result_ty) locn
+ , mkSimpleMatch [WildPat a_ty] fail_expr result_ty locn
]
in
- matchWrapper DoBindMatch the_matches match_msg
- `thenDs` \ (binders, matching_code) ->
+ matchWrapper (DoCtxt do_or_lc) the_matches `thenDs` \ (binders, matching_code) ->
returnDs (mkApps (Var then_id) [Type a_ty, Type b_ty, expr2,
mkLams binders matching_code])
in
where
do_expr expr locn = putSrcLocDs locn (dsExpr expr)
-
- match_msg = case do_or_lc of
- DoStmt -> "`do' statement"
- ListComp -> "comprehension"
\end{code}
mkIntegerLit (denominator r) `thenDs` \ denom ->
returnDs (mkConApp ratio_data_con [Type integer_ty, num, denom])
where
- (ratio_data_con, integer_ty)
- = case splitAlgTyConApp ty of
- (tycon, [i_ty], [con])
- -> ASSERT(isIntegerTy i_ty && tycon `hasKey` ratioTyConKey)
- (con, i_ty)
+ (ratio_data_con, integer_ty)
+ = case tcSplitTyConApp ty of
+ (tycon, [i_ty]) -> ASSERT(isIntegerTy i_ty && tycon `hasKey` ratioTyConKey)
+ (head (tyConDataCons tycon), i_ty)
\end{code}
-
-
-
projects / ghc-hetmet.git / blobdiff