\section[DsExpr]{Matching expressions (Exprs)}
\begin{code}
-#include "HsVersions.h"
-
module DsExpr ( dsExpr ) where
-IMP_Ubiq()
-IMPORT_DELOOPER(DsLoop) -- partly to get dsBinds, partly to chk dsExpr
+#include "HsVersions.h"
+
+import {-# SOURCE #-} DsBinds (dsBinds )
import HsSyn ( failureFreePat,
HsExpr(..), OutPat(..), HsLit(..), ArithSeqInfo(..),
Stmt(..), DoOrListComp(..), Match(..), HsBinds, HsType, Fixity,
GRHSsAndBinds
)
-import TcHsSyn ( SYN_IE(TypecheckedHsExpr), SYN_IE(TypecheckedHsBinds),
- SYN_IE(TypecheckedRecordBinds), SYN_IE(TypecheckedPat),
- SYN_IE(TypecheckedStmt)
+import TcHsSyn ( TypecheckedHsExpr, TypecheckedHsBinds,
+ TypecheckedRecordBinds, TypecheckedPat,
+ TypecheckedStmt,
+ maybeBoxedPrimType
+
)
import CoreSyn
import DsMonad
import DsCCall ( dsCCall )
-import DsHsSyn ( outPatType )
import DsListComp ( dsListComp )
-import DsUtils ( mkAppDs, mkConDs, mkPrimDs, dsExprToAtom,
- mkErrorAppDs, showForErr, EquationInfo,
- MatchResult, SYN_IE(DsCoreArg)
+import DsUtils ( mkAppDs, mkConDs, dsExprToAtomGivenTy,
+ mkErrorAppDs, showForErr, DsCoreArg
)
import Match ( matchWrapper )
-import CoreUtils ( coreExprType, substCoreExpr, argToExpr,
- mkCoreIfThenElse, unTagBinders )
+import CoreUtils ( coreExprType, mkCoreIfThenElse )
import CostCentre ( mkUserCC )
-import FieldLabel ( fieldLabelType, FieldLabel )
-import Id ( idType, nullIdEnv, addOneToIdEnv,
- dataConArgTys, dataConFieldLabels,
- recordSelectorFieldLabel
+import FieldLabel ( FieldLabel )
+import Id ( dataConTyCon, dataConArgTys, dataConFieldLabels,
+ recordSelectorFieldLabel, Id
)
import Literal ( mkMachInt, Literal(..) )
import Name ( Name{--O only-} )
-import PprStyle ( PprStyle(..) )
-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, maybeAppTyCon, getAppTyCon, applyTy,
- maybeBoxedPrimType, splitAppTy
+import PrelVals ( rEC_CON_ERROR_ID, rEC_UPD_ERROR_ID )
+import TyCon ( isNewTyCon )
+import Type ( splitFunTys, typePrimRep, mkTyConApp,
+ splitAlgTyConApp, splitTyConApp_maybe,
+ splitAppTy, Type
)
-import TysPrim ( voidTy )
-import TysWiredIn ( mkTupleTy, tupleCon, nilDataCon, consDataCon, listTyCon,
+import TysWiredIn ( tupleCon, nilDataCon, consDataCon, listTyCon, mkListTy,
charDataCon, charTy
)
-import TyVar ( nullTyVarEnv, addOneToTyVarEnv, GenTyVar{-instance Eq-} )
-import Usage ( SYN_IE(UVar) )
+import TyVar ( GenTyVar{-instance Eq-} )
import Maybes ( maybeToBool )
-import Util ( zipEqual, pprError, panic, assertPanic )
+import Util ( zipEqual )
+import Outputable
-mk_nil_con ty = mkCon nilDataCon [] [ty] [] -- micro utility...
+mk_nil_con ty = mkCon nilDataCon [ty] [] -- micro utility...
\end{code}
The funny business to do with variables is that we look them up in the
| _LENGTH_ s == 1
= let
- the_char = mkCon charDataCon [] [] [LitArg (MachChar (_HEAD_ s))]
+ the_char = mkCon charDataCon [] [LitArg (MachChar (_HEAD_ s))]
the_nil = mk_nil_con charTy
in
mkConDs consDataCon [TyArg charTy, VarArg the_char, VarArg the_nil]
= returnDs (Lit (NoRepStr str))
dsExpr (HsLitOut (HsLitLit s) ty)
- = returnDs ( mkCon data_con [] [] [LitArg (MachLitLit s kind)] )
+ = returnDs ( mkCon data_con [] [LitArg (MachLitLit s kind)] )
where
(data_con, kind)
= case (maybeBoxedPrimType ty) of
Just (boxing_data_con, prim_ty)
-> (boxing_data_con, typePrimRep prim_ty)
Nothing
- -> pprError "ERROR: ``literal-literal'' not a single-constructor type: "
- (ppBesides [ppPStr s, ppStr "; type: ", ppr PprDebug ty])
+ -> pprPanic "ERROR: ``literal-literal'' not a single-constructor type: "
+ (hcat [ptext s, text "; type: ", ppr ty])
dsExpr (HsLitOut (HsInt i) ty)
= returnDs (Lit (NoRepInteger i ty))
-- ToDo: range checking needed!
dsExpr (HsLitOut (HsChar c) _)
- = returnDs ( mkCon charDataCon [] [] [LitArg (MachChar c)] )
+ = returnDs ( mkCon charDataCon [] [LitArg (MachChar c)] )
dsExpr (HsLitOut (HsCharPrim c) _)
= returnDs (Lit (MachChar c))
= 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 fun arg)
+ = dsExpr fun `thenDs` \ core_fun ->
+ dsExpr arg `thenDs` \ core_arg ->
+ dsExprToAtomGivenTy core_arg (coreExprType core_arg) $ \ atom_arg ->
+ returnDs (core_fun `App` atom_arg)
+
\end{code}
Operator sections. At first it looks as if we can convert
will sort it out.
\begin{code}
+dsExpr (OpApp e1 op _ e2)
+ = dsExpr op `thenDs` \ core_op ->
+ -- for the type of y, we need the type of op's 2nd argument
+ let
+ (x_ty:y_ty:_, _) = splitFunTys (coreExprType core_op)
+ in
+ dsExpr e1 `thenDs` \ x_core ->
+ dsExpr e2 `thenDs` \ y_core ->
+ dsExprToAtomGivenTy x_core x_ty $ \ x_atom ->
+ dsExprToAtomGivenTy y_core y_ty $ \ y_atom ->
+ returnDs (core_op `App` x_atom `App` y_atom)
+
dsExpr (SectionL expr op)
- = dsExpr op `thenDs` \ core_op ->
- dsExpr expr `thenDs` \ core_expr ->
- dsExprToAtom (VarArg core_expr) $ \ y_atom ->
-
- -- for the type of x, we need the type of op's 2nd argument
+ = dsExpr op `thenDs` \ core_op ->
+ -- for the type of y, we need the type of op's 2nd argument
let
- x_ty = case (splitSigmaTy (coreExprType core_op)) of { (_, _, tau_ty) ->
- case (splitFunTy tau_ty) of {
- ((_:arg2_ty:_), _) -> arg2_ty;
- _ -> panic "dsExpr:SectionL:arg 2 ty" }}
+ (x_ty:y_ty:_, _) = splitFunTys (coreExprType core_op)
in
- newSysLocalDs x_ty `thenDs` \ x_id ->
- returnDs (mkValLam [x_id] (core_op `App` y_atom `App` VarArg x_id))
+ dsExpr expr `thenDs` \ x_core ->
+ dsExprToAtomGivenTy x_core x_ty $ \ x_atom ->
+
+ newSysLocalDs y_ty `thenDs` \ y_id ->
+ returnDs (mkValLam [y_id] (core_op `App` x_atom `App` VarArg y_id))
-- dsExpr (SectionR op expr) -- \ x -> op x expr
dsExpr (SectionR op expr)
= dsExpr op `thenDs` \ core_op ->
- dsExpr expr `thenDs` \ core_expr ->
- dsExprToAtom (VarArg core_expr) $ \ y_atom ->
-
- -- for the type of x, we need the type of op's 1st argument
+ -- for the type of x, we need the type of op's 2nd argument
let
- x_ty = case (splitSigmaTy (coreExprType core_op)) of { (_, _, tau_ty) ->
- case (splitFunTy tau_ty) of {
- ((arg1_ty:_), _) -> arg1_ty;
- _ -> panic "dsExpr:SectionR:arg 1 ty" }}
+ (x_ty:y_ty:_, _) = splitFunTys (coreExprType core_op)
in
- newSysLocalDs x_ty `thenDs` \ x_id ->
+ dsExpr expr `thenDs` \ y_expr ->
+ dsExprToAtomGivenTy y_expr y_ty $ \ y_atom ->
+
+ newSysLocalDs x_ty `thenDs` \ x_id ->
returnDs (mkValLam [x_id] (core_op `App` VarArg x_id `App` y_atom))
dsExpr (CCall label args may_gc is_asm result_ty)
dsExpr (HsSCC cc expr)
= dsExpr expr `thenDs` \ core_expr ->
getModuleAndGroupDs `thenDs` \ (mod_name, group_name) ->
- returnDs ( SCC (mkUserCC cc mod_name group_name) core_expr)
+ returnDs (Note (SCC (mkUserCC cc mod_name group_name)) core_expr)
dsExpr expr@(HsCase discrim matches src_loc)
= putSrcLocDs src_loc $
returnDs ( mkCoLetAny (NonRec discrim_var core_discrim) matching_code )
dsExpr (HsLet binds expr)
- = dsBinds 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 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 $
+ | maybeToBool maybe_list_comp
+ = -- Special case for list comprehensions
+ putSrcLocDs src_loc $
dsListComp stmts elt_ty
| otherwise
= putSrcLocDs src_loc $
dsDo do_or_lc stmts return_id then_id zero_id result_ty
where
- maybe_list_comp = case maybeAppTyCon result_ty of
- Just (tycon, [elt_ty]) | tycon == listTyCon
- -> Just elt_ty
- other -> Nothing
+ 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
dsExpr (HsIf guard_expr then_expr else_expr src_loc)
= dsExpr expr `thenDs` \ core_expr ->
returnDs (mkTyLam tyvars core_expr)
-dsExpr expr@(TyApp e tys) = dsApp expr []
+dsExpr (TyApp expr tys)
+ = dsExpr expr `thenDs` \ core_expr ->
+ returnDs (mkTyApp core_expr tys)
\end{code}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
dsExpr (ExplicitListOut ty xs)
- = case xs of
- [] -> returnDs (mk_nil_con ty)
- (y:ys) ->
- dsExpr y `thenDs` \ core_hd ->
- dsExpr (ExplicitListOut ty ys) `thenDs` \ core_tl ->
- mkConDs consDataCon [TyArg ty, VarArg core_hd, VarArg core_tl]
+ = go xs
+ where
+ list_ty = mkListTy ty
+
+ -- xs can ocasaionlly be huge, so don't try to take
+ -- coreExprType of core_xs, as dsArgToAtom does
+ -- (that gives a quadratic algorithm)
+ go [] = returnDs (mk_nil_con ty)
+ go (x:xs) = dsExpr x `thenDs` \ core_x ->
+ dsExprToAtomGivenTy core_x ty $ \ arg_x ->
+ go xs `thenDs` \ core_xs ->
+ dsExprToAtomGivenTy core_xs list_ty $ \ arg_xs ->
+ returnDs (Con consDataCon [TyArg ty, arg_x, arg_xs])
dsExpr (ExplicitTuple expr_list)
= mapDs dsExpr expr_list `thenDs` \ core_exprs ->
mkConDs (tupleCon (length expr_list))
(map (TyArg . coreExprType) core_exprs ++ map VarArg core_exprs)
+dsExpr (HsCon con_id [ty] [arg])
+ | isNewTyCon tycon
+ = dsExpr arg `thenDs` \ arg' ->
+ returnDs (Note (Coerce result_ty (coreExprType arg')) arg')
+ where
+ result_ty = mkTyConApp tycon [ty]
+ tycon = dataConTyCon con_id
+
+dsExpr (HsCon con_id tys args)
+ = mapDs dsExpr args `thenDs` \ args2 ->
+ mkConDs con_id (map TyArg tys ++ map VarArg args2)
+
dsExpr (ArithSeqOut expr (From from))
= dsExpr expr `thenDs` \ expr2 ->
dsExpr from `thenDs` \ from2 ->
\begin{code}
-dsExpr (RecordCon con_expr rbinds)
+dsExpr (RecordCon con_id con_expr rbinds)
= dsExpr con_expr `thenDs` \ con_expr' ->
let
- con_id = get_con con_expr'
- (arg_tys, _) = splitFunTy (coreExprType con_expr')
+ (arg_tys, _) = splitFunTys (coreExprType con_expr')
mk_arg (arg_ty, lbl)
= case [rhs | (sel_id,rhs,_) <- rbinds,
in
mapDs mk_arg (zipEqual "dsExpr:RecordCon" arg_tys (dataConFieldLabels con_id)) `thenDs` \ con_args ->
mkAppDs con_expr' (map VarArg con_args)
- where
- -- "con_expr'" is simply an application of the constructor Id
- -- to types and (perhaps) dictionaries. This gets the constructor...
- get_con (Var con) = con
- get_con (App fun _) = get_con fun
\end{code}
Record update is a little harder. Suppose we have the decl:
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) = splitAlgTyConApp record_in_ty
+ (_, out_inst_tys, _) = splitAlgTyConApp 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 ->
\begin{code}
dsExpr (DictLam dictvars expr)
= dsExpr expr `thenDs` \ core_expr ->
- returnDs( mkValLam dictvars core_expr )
+ returnDs (mkValLam dictvars core_expr)
------------------
-dsExpr expr@(DictApp e dicts) -- becomes a curried application
- = dsApp expr []
+dsExpr (DictApp expr dicts) -- becomes a curried application
+ = mapDs lookupEnvDs dicts `thenDs` \ core_dicts ->
+ dsExpr expr `thenDs` \ core_expr ->
+ returnDs (foldl (\f d -> f `App` (VarArg d)) core_expr core_dicts)
\end{code}
-@SingleDicts@ become @Locals@; @Dicts@ turn into tuples, unless
-of length 0 or 1.
-@ClassDictLam dictvars methods expr@ is ``the opposite'':
-\begin{verbatim}
-\ x -> case x of ( dictvars-and-methods-tuple ) -> expr
-\end{verbatim}
\begin{code}
-dsExpr (SingleDict dict) -- just a local
- = lookupEnvWithDefaultDs dict (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 ->
- (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 (ClassDictLam dicts methods expr)
- = dsExpr expr `thenDs` \ core_expr ->
- case num_of_d_and_ms of
- 0 -> newSysLocalDs voidTy `thenDs` \ new_x ->
- returnDs (mkValLam [new_x] core_expr)
-
- 1 -> -- no untupling
- returnDs (mkValLam dicts_and_methods core_expr)
-
- _ -> -- untuple it
- newSysLocalDs tuple_ty `thenDs` \ new_x ->
- returnDs (
- Lam (ValBinder new_x)
- (Case (Var new_x)
- (AlgAlts
- [(tuple_con, dicts_and_methods, core_expr)]
- NoDefault)))
- where
- num_of_d_and_ms = length dicts + length methods
- dicts_and_methods = dicts ++ methods
- tuple_ty = mkTupleTy num_of_d_and_ms (map idType dicts_and_methods)
- tuple_con = tupleCon num_of_d_and_ms
#ifdef DEBUG
-- HsSyn constructs that just shouldn't be here:
= " out of range: [" ++ show minInt ++ ", " ++ show maxInt ++ "]\n"
\end{code}
-%--------------------------------------------------------------------
-
-@(dsApp e [t_1,..,t_n, e_1,..,e_n])@ returns something with the same
-value as:
-\begin{verbatim}
-e t_1 ... t_n e_1 .. e_n
-\end{verbatim}
-We're doing all this so we can saturate constructors (as painlessly as
-possible).
+%--------------------------------------------------------------------
\begin{code}
-dsApp :: TypecheckedHsExpr -- expr to desugar
- -> [DsCoreArg] -- accumulated ty/val args: NB:
- -> DsM CoreExpr -- final result
-
-dsApp (HsApp e1 e2) args
- = dsExpr e2 `thenDs` \ core_e2 ->
- dsApp e1 (VarArg core_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)
-
-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 anything_else args
- = dsExpr anything_else `thenDs` \ core_expr ->
- mkAppDs core_expr args
-
dsId v
- = lookupEnvDs v `thenDs` \ maybe_expr ->
- returnDs (case maybe_expr of { Nothing -> Var v; Just expr -> expr })
+ = lookupEnvDs v `thenDs` \ v' ->
+ returnDs (Var v')
\end{code}
\begin{code}
= continue_with []
dsRbinds ((sel_id, rhs, pun_flag) : rbinds) continue_with
- = dsExpr rhs `thenDs` \ rhs' ->
- dsExprToAtom (VarArg rhs') $ \ rhs_atom ->
- dsRbinds rbinds $ \ rbinds' ->
+ = dsExpr rhs `thenDs` \ rhs' ->
+ dsExprToAtomGivenTy rhs' (coreExprType rhs') $ \ rhs_atom ->
+ dsRbinds rbinds $ \ rbinds' ->
continue_with ((sel_id, rhs_atom) : rbinds')
\end{code}
-\begin{code}
--- do_unfold ty_env val_env (Lam (TyBinder tyvar) body) (TyArg ty : args)
--- = do_unfold (addOneToTyVarEnv ty_env tyvar ty) val_env body args
---
--- do_unfold ty_env val_env (Lam (ValBinder binder) body) (arg@(VarArg expr) : args)
--- = dsExprToAtom arg $ \ arg_atom ->
--- do_unfold ty_env
--- (addOneToIdEnv val_env binder (argToExpr arg_atom))
--- body args
---
--- do_unfold ty_env val_env body args
--- = -- Clone the remaining part of the template
--- uniqSMtoDsM (substCoreExpr val_env ty_env body) `thenDs` \ body' ->
---
--- -- Apply result to remaining arguments
--- mkAppDs body' args
-\end{code}
-
Basically does the translation given in the Haskell~1.3 report:
\begin{code}
dsDo :: DoOrListComp
VarArg (mkValLam [ignored_result_id] rest)]
go (LetStmt binds : stmts )
- = dsBinds binds `thenDs` \ binds2 ->
- go stmts `thenDs` \ rest ->
+ = dsBinds False binds `thenDs` \ binds2 ->
+ go stmts `thenDs` \ rest ->
returnDs (mkCoLetsAny binds2 rest)
go (BindStmt pat expr locn : stmts)
projects / ghc-hetmet.git / blobdiff