module DsExpr ( dsExpr ) where
IMP_Ubiq()
+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ <= 201
IMPORT_DELOOPER(DsLoop) -- partly to get dsBinds, partly to chk dsExpr
+#else
+import {-# SOURCE #-} DsBinds (dsBinds )
+#endif
import HsSyn ( failureFreePat,
HsExpr(..), OutPat(..), HsLit(..), ArithSeqInfo(..),
- Stmt(..), Match(..), Qualifier, HsBinds, HsType,
+ Stmt(..), DoOrListComp(..), Match(..), HsBinds, HsType, Fixity,
GRHSsAndBinds
)
import TcHsSyn ( SYN_IE(TypecheckedHsExpr), SYN_IE(TypecheckedHsBinds),
import DsCCall ( dsCCall )
import DsHsSyn ( outPatType )
import DsListComp ( dsListComp )
-import DsUtils ( mkAppDs, mkConDs, mkPrimDs, dsExprToAtom,
+import DsUtils ( mkAppDs, mkConDs, mkPrimDs, dsExprToAtom, mkTupleExpr,
mkErrorAppDs, showForErr, EquationInfo,
MatchResult, SYN_IE(DsCoreArg)
)
import FieldLabel ( fieldLabelType, FieldLabel )
import Id ( idType, nullIdEnv, addOneToIdEnv,
dataConArgTys, dataConFieldLabels,
- recordSelectorFieldLabel
+ recordSelectorFieldLabel, SYN_IE(Id)
)
import Literal ( mkMachInt, Literal(..) )
import Name ( Name{--O only-} )
-import PprStyle ( PprStyle(..) )
+import Outputable ( PprStyle(..), Outputable(..) )
import PprType ( GenType )
import PrelVals ( rEC_CON_ERROR_ID, rEC_UPD_ERROR_ID, voidId )
-import Pretty ( ppShow, ppBesides, ppPStr, ppStr )
-import TyCon ( isDataTyCon, isNewTyCon )
-import Type ( splitSigmaTy, splitFunTy, typePrimRep,
- getAppDataTyConExpandingDicts, getAppTyCon, applyTy,
- maybeBoxedPrimType
+import Pretty ( Doc, hcat, ptext, text )
+import Type ( splitSigmaTy, splitFunTy, typePrimRep,
+ getAppDataTyConExpandingDicts, maybeAppTyCon, getAppTyCon, applyTy,
+ maybeBoxedPrimType, splitAppTy, SYN_IE(Type)
)
import TysPrim ( voidTy )
-import TysWiredIn ( mkTupleTy, tupleCon, nilDataCon, consDataCon,
+import TysWiredIn ( mkTupleTy, tupleCon, nilDataCon, consDataCon, listTyCon,
charDataCon, charTy
)
import TyVar ( nullTyVarEnv, addOneToTyVarEnv, GenTyVar{-instance Eq-} )
import Usage ( SYN_IE(UVar) )
+import Maybes ( maybeToBool )
import Util ( zipEqual, pprError, panic, assertPanic )
mk_nil_con ty = mkCon nilDataCon [] [ty] [] -- micro utility...
\begin{code}
dsExpr :: TypecheckedHsExpr -> DsM CoreExpr
-dsExpr e@(HsVar var) = dsApp e []
+dsExpr e@(HsVar var) = dsId var
\end{code}
%************************************************************************
-> (boxing_data_con, typePrimRep prim_ty)
Nothing
-> pprError "ERROR: ``literal-literal'' not a single-constructor type: "
- (ppBesides [ppPStr s, ppStr "; type: ", ppr PprDebug ty])
+ (hcat [ptext s, text "; type: ", ppr PprDebug ty])
dsExpr (HsLitOut (HsInt i) ty)
= returnDs (Lit (NoRepInteger i ty))
= matchWrapper LambdaMatch [a_Match] "lambda" `thenDs` \ (binders, matching_code) ->
returnDs ( mkValLam binders matching_code )
-dsExpr expr@(HsApp e1 e2) = dsApp expr []
-dsExpr expr@(OpApp e1 op e2) = dsApp expr []
+dsExpr expr@(HsApp e1 e2) = dsApp expr []
+dsExpr expr@(OpApp e1 op _ e2) = dsApp expr []
\end{code}
Operator sections. At first it looks as if we can convert
matchWrapper CaseMatch matches "case" `thenDs` \ ([discrim_var], matching_code) ->
returnDs ( mkCoLetAny (NonRec discrim_var core_discrim) matching_code )
-dsExpr (ListComp expr quals)
- = dsExpr expr `thenDs` \ core_expr ->
- dsListComp core_expr quals
-
dsExpr (HsLet binds expr)
- = dsBinds False binds `thenDs` \ core_binds ->
- dsExpr expr `thenDs` \ core_expr ->
+ = dsBinds False binds `thenDs` \ core_binds ->
+ dsExpr expr `thenDs` \ core_expr ->
returnDs ( mkCoLetsAny core_binds core_expr )
-dsExpr (HsDoOut stmts then_id zero_id src_loc)
+dsExpr (HsDoOut do_or_lc stmts return_id then_id zero_id result_ty src_loc)
+ | maybeToBool maybe_list_comp
+ = -- Special case for list comprehensions
+ putSrcLocDs src_loc $
+ dsListComp stmts elt_ty
+
+ | otherwise
= putSrcLocDs src_loc $
- dsDo then_id zero_id stmts
+ dsDo do_or_lc stmts return_id then_id zero_id result_ty
+ where
+ maybe_list_comp
+ = case (do_or_lc, maybeAppTyCon 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
dsExpr (HsIf guard_expr then_expr else_expr src_loc)
= putSrcLocDs src_loc $
dictionaries.
\begin{code}
-dsExpr (RecordUpdOut record_expr dicts rbinds)
+dsExpr (RecordUpdOut record_expr record_out_ty dicts rbinds)
= dsExpr record_expr `thenDs` \ record_expr' ->
-- Desugar the rbinds, and generate let-bindings if
-- necessary so that we don't lose sharing
dsRbinds rbinds $ \ rbinds' ->
let
- record_ty = coreExprType record_expr'
- (tycon, inst_tys, cons) = --trace "DsExpr.getAppDataTyConExpandingDicts" $
- getAppDataTyConExpandingDicts record_ty
- cons_to_upd = filter has_all_fields cons
+ record_in_ty = coreExprType record_expr'
+ (tycon, in_inst_tys, cons) = getAppDataTyConExpandingDicts record_in_ty
+ (_, out_inst_tys, _) = getAppDataTyConExpandingDicts record_out_ty
+ cons_to_upd = filter has_all_fields cons
-- initial_args are passed to every constructor
- initial_args = map TyArg inst_tys ++ map VarArg dicts
+ initial_args = map TyArg out_inst_tys ++ map VarArg dicts
mk_val_arg (field, arg_id)
= case [arg | (f, arg) <- rbinds',
[] -> VarArg arg_id
mk_alt con
- = newSysLocalsDs (dataConArgTys con inst_tys) `thenDs` \ arg_ids ->
+ = newSysLocalsDs (dataConArgTys con in_inst_tys) `thenDs` \ arg_ids ->
let
val_args = map mk_val_arg (zipEqual "dsExpr:RecordUpd" (dataConFieldLabels con) arg_ids)
in
| length cons_to_upd == length cons
= returnDs NoDefault
| otherwise
- = newSysLocalDs record_ty `thenDs` \ deflt_id ->
- mkErrorAppDs rEC_UPD_ERROR_ID record_ty "" `thenDs` \ err ->
+ = newSysLocalDs record_in_ty `thenDs` \ deflt_id ->
+ mkErrorAppDs rEC_UPD_ERROR_ID record_out_ty "" `thenDs` \ err ->
returnDs (BindDefault deflt_id err)
in
mapDs mk_alt cons_to_upd `thenDs` \ alts ->
\end{verbatim}
\begin{code}
dsExpr (SingleDict dict) -- just a local
- = lookupEnvWithDefaultDs dict (Var dict)
+ = lookupEnvDs dict `thenDs` \ dict' ->
+ returnDs (Var dict')
-dsExpr (Dictionary dicts methods)
- = -- hey, these things may have been substituted away...
- zipWithDs lookupEnvWithDefaultDs
- dicts_and_methods dicts_and_methods_exprs
- `thenDs` \ core_d_and_ms ->
+dsExpr (Dictionary [] []) -- Empty dictionary represented by void,
+ = returnDs (Var voidId) -- (not, as would happen if we took the next case, by ())
- (case num_of_d_and_ms of
- 0 -> returnDs (Var voidId)
-
- 1 -> returnDs (head core_d_and_ms) -- just a single Id
-
- _ -> -- tuple 'em up
- mkConDs (tupleCon num_of_d_and_ms)
- (map (TyArg . coreExprType) core_d_and_ms ++ map VarArg core_d_and_ms)
- )
- where
- dicts_and_methods = dicts ++ methods
- dicts_and_methods_exprs = map Var dicts_and_methods
- num_of_d_and_ms = length dicts_and_methods
+dsExpr (Dictionary dicts methods)
+ = mapDs lookupEnvDs (dicts ++ methods) `thenDs` \ d_and_ms' ->
+ returnDs (mkTupleExpr d_and_ms')
dsExpr (ClassDictLam dicts methods expr)
= dsExpr expr `thenDs` \ core_expr ->
#ifdef DEBUG
-- HsSyn constructs that just shouldn't be here:
-dsExpr (HsDo _ _) = panic "dsExpr:HsDo"
+dsExpr (HsDo _ _ _) = panic "dsExpr:HsDo"
dsExpr (ExplicitList _) = panic "dsExpr:ExplicitList"
dsExpr (ExprWithTySig _ _) = panic "dsExpr:ExprWithTySig"
dsExpr (ArithSeqIn _) = panic "dsExpr:ArithSeqIn"
= dsExpr e2 `thenDs` \ core_e2 ->
dsApp e1 (VarArg core_e2 : args)
-dsApp (OpApp e1 op e2) args
+dsApp (OpApp e1 op _ e2) args
= dsExpr e1 `thenDs` \ core_e1 ->
dsExpr e2 `thenDs` \ core_e2 ->
dsApp op (VarArg core_e1 : VarArg core_e2 : args)
dsApp (DictApp expr dicts) args
- = -- now, those dicts may have been substituted away...
- zipWithDs lookupEnvWithDefaultDs dicts (map Var dicts)
- `thenDs` \ core_dicts ->
- dsApp expr (map VarArg core_dicts ++ args)
+ = mapDs lookupEnvDs dicts `thenDs` \ core_dicts ->
+ dsApp expr (map (VarArg . Var) core_dicts ++ args)
dsApp (TyApp expr tys) args
= dsApp expr (map TyArg tys ++ args)
-- we might should look out for SectionLs, etc., here, but we don't
-dsApp (HsVar v) args
- = lookupEnvDs v `thenDs` \ maybe_expr ->
- mkAppDs (case maybe_expr of { Nothing -> Var v; Just expr -> expr }) args
-
dsApp anything_else args
= dsExpr anything_else `thenDs` \ core_expr ->
mkAppDs core_expr args
+
+dsId v
+ = lookupEnvDs v `thenDs` \ v' ->
+ returnDs (Var v')
\end{code}
\begin{code}
Basically does the translation given in the Haskell~1.3 report:
\begin{code}
-dsDo :: Id -- id for: (>>=) m
- -> Id -- id for: zero m
+dsDo :: DoOrListComp
-> [TypecheckedStmt]
+ -> Id -- id for: return m
+ -> Id -- id for: (>>=) m
+ -> Id -- id for: zero m
+ -> Type -- Element type; the whole expression has type (m t)
-> DsM CoreExpr
-dsDo then_id zero_id (stmt:stmts)
- = case stmt of
- ExprStmt expr locn -> ASSERT( null stmts ) do_expr expr locn
-
- ExprStmtOut expr locn a b ->
- do_expr expr locn `thenDs` \ expr2 ->
- ds_rest `thenDs` \ rest ->
- newSysLocalDs a `thenDs` \ ignored_result_id ->
- dsApp (HsVar then_id) [TyArg a, TyArg b, VarArg expr2,
- VarArg (mkValLam [ignored_result_id] rest)]
-
- LetStmt binds ->
- dsBinds False binds `thenDs` \ binds2 ->
- ds_rest `thenDs` \ rest ->
- returnDs (mkCoLetsAny binds2 rest)
-
- BindStmtOut pat expr locn a b ->
- do_expr expr locn `thenDs` \ expr2 ->
- let
- zero_expr = TyApp (HsVar zero_id) [b]
- main_match
- = PatMatch pat (SimpleMatch (HsDoOut stmts then_id zero_id locn))
- the_matches
- = if failureFreePat pat
- then [main_match]
- else [main_match, PatMatch (WildPat a) (SimpleMatch zero_expr)]
- in
- matchWrapper DoBindMatch the_matches "`do' statement"
- `thenDs` \ (binders, matching_code) ->
- dsApp (HsVar then_id) [TyArg a, TyArg b,
- VarArg expr2, VarArg (mkValLam binders matching_code)]
+dsDo do_or_lc stmts return_id then_id zero_id result_ty
+ = dsId return_id `thenDs` \ return_ds ->
+ dsId then_id `thenDs` \ then_ds ->
+ dsId zero_id `thenDs` \ zero_ds ->
+ let
+ (_, b_ty) = splitAppTy result_ty -- result_ty must be of the form (m b)
+
+ go [ReturnStmt expr]
+ = dsExpr expr `thenDs` \ expr2 ->
+ mkAppDs return_ds [TyArg b_ty, VarArg expr2]
+
+ go (GuardStmt expr locn : stmts)
+ = do_expr expr locn `thenDs` \ expr2 ->
+ go stmts `thenDs` \ rest ->
+ mkAppDs zero_ds [TyArg b_ty] `thenDs` \ zero_expr ->
+ returnDs (mkCoreIfThenElse expr2 rest zero_expr)
+
+ go (ExprStmt expr locn : stmts)
+ = do_expr expr locn `thenDs` \ expr2 ->
+ let
+ (_, a_ty) = splitAppTy (coreExprType expr2) -- Must be of form (m a)
+ in
+ if null stmts then
+ returnDs expr2
+ else
+ go stmts `thenDs` \ rest ->
+ newSysLocalDs a_ty `thenDs` \ ignored_result_id ->
+ mkAppDs then_ds [TyArg a_ty, TyArg b_ty, VarArg expr2,
+ VarArg (mkValLam [ignored_result_id] rest)]
+
+ go (LetStmt binds : stmts )
+ = dsBinds False binds `thenDs` \ binds2 ->
+ go stmts `thenDs` \ rest ->
+ returnDs (mkCoLetsAny binds2 rest)
+
+ go (BindStmt pat expr locn : stmts)
+ = putSrcLocDs locn $
+ dsExpr expr `thenDs` \ expr2 ->
+ let
+ (_, a_ty) = splitAppTy (coreExprType expr2) -- Must be of form (m a)
+ zero_expr = TyApp (HsVar zero_id) [b_ty]
+ main_match = PatMatch pat (SimpleMatch (
+ HsDoOut do_or_lc stmts return_id then_id zero_id result_ty locn))
+ the_matches
+ = if failureFreePat pat
+ then [main_match]
+ else [main_match, PatMatch (WildPat a_ty) (SimpleMatch zero_expr)]
+ in
+ matchWrapper DoBindMatch the_matches match_msg
+ `thenDs` \ (binders, matching_code) ->
+ mkAppDs then_ds [TyArg a_ty, TyArg b_ty,
+ VarArg expr2, VarArg (mkValLam binders matching_code)]
+ in
+ go stmts
+
where
- ds_rest = dsDo then_id zero_id stmts
do_expr expr locn = putSrcLocDs locn (dsExpr expr)
-#ifdef DEBUG
-dsDo then_expr zero_expr [] = panic "dsDo:[]"
-#endif
+ match_msg = case do_or_lc of
+ DoStmt -> "`do' statement"
+ ListComp -> "comprehension"
\end{code}
projects / ghc-hetmet.git / blobdiff