%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[DsExpr]{Matching expressions (Exprs)}
\begin{code}
-#include "HsVersions.h"
+module DsExpr ( dsExpr, dsLet ) where
-module DsExpr ( dsExpr ) where
+#include "HsVersions.h"
-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(..), DoOrListComp(..), Match(..), HsBinds, HsType, Fixity,
- GRHSsAndBinds
+ Stmt(..), StmtCtxt(..), Match(..), HsBinds(..), MonoBinds(..),
+ mkSimpleMatch
)
-import TcHsSyn ( SYN_IE(TypecheckedHsExpr), SYN_IE(TypecheckedHsBinds),
- SYN_IE(TypecheckedRecordBinds), SYN_IE(TypecheckedPat),
- SYN_IE(TypecheckedStmt)
+import TcHsSyn ( TypecheckedHsExpr, TypecheckedHsBinds,
+ TypecheckedStmt
)
import CoreSyn
+import CoreUtils ( exprType, mkIfThenElse, bindNonRec )
import DsMonad
-import DsCCall ( dsCCall )
-import DsHsSyn ( outPatType )
+import DsBinds ( dsMonoBinds, AutoScc(..) )
+import DsGRHSs ( dsGuarded )
+import DsCCall ( dsCCall, resultWrapper )
import DsListComp ( dsListComp )
-import DsUtils ( mkAppDs, mkConDs, mkPrimDs, dsExprToAtomGivenTy, mkTupleExpr,
- mkErrorAppDs, showForErr, EquationInfo,
- MatchResult, SYN_IE(DsCoreArg)
+import DsUtils ( mkErrorAppDs, mkDsLets, mkStringLit, mkStringLitFS,
+ mkConsExpr, mkNilExpr, mkIntegerLit
)
-import Match ( matchWrapper )
+import Match ( matchWrapper, matchSimply )
-import CoreUtils ( coreExprType, substCoreExpr, argToExpr,
- mkCoreIfThenElse, unTagBinders )
import CostCentre ( mkUserCC )
-import FieldLabel ( fieldLabelType, FieldLabel )
-import Id ( idType, nullIdEnv, addOneToIdEnv,
- dataConArgTys, dataConFieldLabels,
- recordSelectorFieldLabel, SYN_IE(Id)
- )
-import Literal ( mkMachInt, Literal(..) )
-import Name ( Name{--O only-} )
-import Outputable ( PprStyle(..), Outputable(..) )
-import PprType ( GenType )
-import PrelVals ( rEC_CON_ERROR_ID, rEC_UPD_ERROR_ID, voidId )
-import Pretty ( Doc, hcat, ptext, text )
-import Type ( splitSigmaTy, splitFunTy, typePrimRep,
- getAppDataTyConExpandingDicts, maybeAppTyCon, getAppTyCon, applyTy,
- maybeBoxedPrimType, splitAppTy, SYN_IE(Type)
+import Id ( Id, idType, recordSelectorFieldLabel )
+import PrelInfo ( rEC_CON_ERROR_ID, iRREFUT_PAT_ERROR_ID )
+import DataCon ( DataCon, dataConWrapId, dataConArgTys, dataConFieldLabels )
+import DataCon ( isExistentialDataCon )
+import Literal ( Literal(..) )
+import Type ( splitFunTys,
+ splitAlgTyConApp, splitAlgTyConApp_maybe, splitTyConApp_maybe,
+ splitAppTy, isUnLiftedType, Type
)
-import TysPrim ( voidTy )
-import TysWiredIn ( mkTupleTy, tupleCon, nilDataCon, consDataCon, listTyCon, mkListTy,
- charDataCon, charTy
- )
-import TyVar ( nullTyVarEnv, addOneToTyVarEnv, GenTyVar{-instance Eq-} )
-import Usage ( SYN_IE(UVar) )
+import TysWiredIn ( tupleCon, listTyCon, charDataCon, intDataCon, isIntegerTy )
+import BasicTypes ( RecFlag(..), Boxity(..) )
import Maybes ( maybeToBool )
-import Util ( zipEqual, pprError, panic, assertPanic )
+import PrelNames ( hasKey, ratioTyConKey )
+import Util ( zipEqual, zipWithEqual )
+import Outputable
-mk_nil_con ty = mkCon nilDataCon [] [ty] [] -- micro utility...
+import Ratio ( numerator, denominator )
\end{code}
-The funny business to do with variables is that we look them up in the
-Id-to-Id and Id-to-Id maps that the monadery is carrying
-around; if we get hits, we use the value accordingly.
%************************************************************************
%* *
-\subsection[DsExpr-vars-and-cons]{Variables and constructors}
+\subsection{dsLet}
%* *
%************************************************************************
-\begin{code}
-dsExpr :: TypecheckedHsExpr -> DsM CoreExpr
+@dsLet@ is a match-result transformer, taking the @MatchResult@ for the body
+and transforming it into one for the let-bindings enclosing the body.
+
+This may seem a bit odd, but (source) let bindings can contain unboxed
+binds like
+\begin{verbatim}
+ C x# = e
+\end{verbatim}
+This must be transformed to a case expression and, if the type has
+more than one constructor, may fail.
-dsExpr e@(HsVar var) = dsId var
+\begin{code}
+dsLet :: TypecheckedHsBinds -> CoreExpr -> DsM CoreExpr
+
+dsLet EmptyBinds body
+ = returnDs body
+
+dsLet (ThenBinds b1 b2) body
+ = dsLet b2 body `thenDs` \ body' ->
+ dsLet b1 body'
+
+-- Special case for bindings which bind unlifted variables
+-- 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]
+ = 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
+ where
+ result_ty = exprType body
+
+-- 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}
%************************************************************************
%* *
-\subsection[DsExpr-literals]{Literals}
+\subsection[DsExpr-vars-and-cons]{Variables, constructors, literals}
%* *
%************************************************************************
-We give int/float literals type Integer and Rational, respectively.
-The typechecker will (presumably) have put \tr{from{Integer,Rational}s}
-around them.
-
-ToDo: put in range checks for when converting "i"
-(or should that be in the typechecker?)
-
-For numeric literals, we try to detect there use at a standard type
-(Int, Float, etc.) are directly put in the right constructor.
-[NB: down with the @App@ conversion.]
-Otherwise, we punt, putting in a "NoRep" Core literal (where the
-representation decisions are delayed)...
-
-See also below where we look for @DictApps@ for \tr{plusInt}, etc.
-
\begin{code}
-dsExpr (HsLitOut (HsString s) _)
- | _NULL_ s
- = returnDs (mk_nil_con charTy)
-
- | _LENGTH_ s == 1
- = let
- 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]
-
--- "_" => build (\ c n -> c 'c' n) -- LATER
-
--- "str" ==> build (\ c n -> foldr charTy T c n "str")
-
-{- LATER:
-dsExpr (HsLitOut (HsString str) _)
- = newTyVarsDs [alphaTyVar] `thenDs` \ [new_tyvar] ->
- let
- new_ty = mkTyVarTy new_tyvar
- in
- newSysLocalsDs [
- charTy `mkFunTy` (new_ty `mkFunTy` new_ty),
- new_ty,
- mkForallTy [alphaTyVar]
- ((charTy `mkFunTy` (alphaTy `mkFunTy` alphaTy))
- `mkFunTy` (alphaTy `mkFunTy` alphaTy))
- ] `thenDs` \ [c,n,g] ->
- returnDs (mkBuild charTy new_tyvar c n g (
- foldl App
- (CoTyApp (CoTyApp (Var foldrId) charTy) new_ty) *** ensure non-prim type ***
- [VarArg c,VarArg n,LitArg (NoRepStr str)]))
--}
-
--- otherwise, leave it as a NoRepStr;
--- the Core-to-STG pass will wrap it in an application of "unpackCStringId".
-
-dsExpr (HsLitOut (HsString str) _)
- = returnDs (Lit (NoRepStr str))
-
-dsExpr (HsLitOut (HsLitLit s) ty)
- = 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: "
- (hcat [ptext s, text "; type: ", ppr PprDebug ty])
-
-dsExpr (HsLitOut (HsInt i) ty)
- = returnDs (Lit (NoRepInteger i ty))
-
-dsExpr (HsLitOut (HsFrac r) ty)
- = returnDs (Lit (NoRepRational r ty))
-
--- others where we know what to do:
-
-dsExpr (HsLitOut (HsIntPrim i) _)
- = if (i >= toInteger minInt && i <= toInteger maxInt) then
- returnDs (Lit (mkMachInt i))
- else
- error ("ERROR: Int constant " ++ show i ++ out_of_range_msg)
-
-dsExpr (HsLitOut (HsFloatPrim f) _)
- = returnDs (Lit (MachFloat f))
- -- ToDo: range checking needed!
-
-dsExpr (HsLitOut (HsDoublePrim d) _)
- = returnDs (Lit (MachDouble d))
- -- ToDo: range checking needed!
-
-dsExpr (HsLitOut (HsChar c) _)
- = returnDs ( mkCon charDataCon [] [] [LitArg (MachChar c)] )
-
-dsExpr (HsLitOut (HsCharPrim c) _)
- = returnDs (Lit (MachChar c))
-
-dsExpr (HsLitOut (HsStringPrim s) _)
- = returnDs (Lit (MachStr s))
+dsExpr :: TypecheckedHsExpr -> DsM CoreExpr
--- end of literals magic. --
+dsExpr (HsVar var) = returnDs (Var var)
+dsExpr (HsIPVar var) = returnDs (Var var)
+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) ->
- returnDs ( mkValLam binders matching_code )
+ returnDs (mkLams binders matching_code)
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)
+ returnDs (core_fun `App` core_arg)
\end{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:_, _) = splitFunTy (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)
+ returnDs (mkApps core_op [x_core, y_core])
dsExpr (SectionL expr op)
= dsExpr op `thenDs` \ core_op ->
-- for the type of y, we need the type of op's 2nd argument
let
- (x_ty:y_ty:_, _) = splitFunTy (coreExprType core_op)
+ (x_ty:y_ty:_, _) = splitFunTys (exprType core_op)
in
dsExpr expr `thenDs` \ x_core ->
- dsExprToAtomGivenTy x_core x_ty $ \ x_atom ->
-
+ newSysLocalDs x_ty `thenDs` \ x_id ->
newSysLocalDs y_ty `thenDs` \ y_id ->
- returnDs (mkValLam [y_id] (core_op `App` x_atom `App` VarArg y_id))
+
+ returnDs (bindNonRec x_id x_core $
+ Lam y_id (mkApps core_op [Var x_id, Var y_id]))
-- dsExpr (SectionR op expr) -- \ x -> op x expr
dsExpr (SectionR op expr)
= dsExpr op `thenDs` \ core_op ->
-- for the type of x, we need the type of op's 2nd argument
let
- (x_ty:y_ty:_, _) = splitFunTy (coreExprType core_op)
+ (x_ty:y_ty:_, _) = splitFunTys (exprType core_op)
in
- dsExpr expr `thenDs` \ y_expr ->
- dsExprToAtomGivenTy y_expr y_ty $ \ y_atom ->
-
+ dsExpr expr `thenDs` \ y_core ->
newSysLocalDs x_ty `thenDs` \ x_id ->
- returnDs (mkValLam [x_id] (core_op `App` VarArg x_id `App` y_atom))
+ newSysLocalDs y_ty `thenDs` \ y_id ->
+
+ returnDs (bindNonRec y_id y_core $
+ Lam x_id (mkApps core_op [Var x_id, Var y_id]))
-dsExpr (CCall label args may_gc is_asm result_ty)
+dsExpr (HsCCall lbl args may_gc is_asm result_ty)
= mapDs dsExpr args `thenDs` \ core_args ->
- dsCCall label core_args may_gc is_asm result_ty
+ dsCCall lbl core_args may_gc is_asm result_ty
-- dsCCall does all the unboxification, etc.
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)
+ getModuleDs `thenDs` \ mod_name ->
+ returnDs (Note (SCC (mkUserCC cc mod_name)) core_expr)
+
+-- special case to handle unboxed tuple patterns.
+
+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) ->
+ 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 _ = False
-dsExpr expr@(HsCase discrim matches src_loc)
+dsExpr (HsCase discrim matches src_loc)
= putSrcLocDs src_loc $
- dsExpr discrim `thenDs` \ core_discrim ->
- matchWrapper CaseMatch matches "case" `thenDs` \ ([discrim_var], matching_code) ->
- returnDs ( mkCoLetAny (NonRec discrim_var core_discrim) matching_code )
-
-dsExpr (HsLet binds 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)
+ dsExpr discrim `thenDs` \ core_discrim ->
+ matchWrapper CaseMatch matches "case" `thenDs` \ ([discrim_var], matching_code) ->
+ returnDs (bindNonRec discrim_var core_discrim matching_code)
+
+dsExpr (HsLet binds body)
+ = dsExpr body `thenDs` \ body' ->
+ dsLet binds body'
+
+dsExpr (HsWith expr binds)
+ = dsExpr expr `thenDs` \ expr' ->
+ foldlDs dsIPBind expr' binds
+ where
+ dsIPBind body (n, e)
+ = dsExpr e `thenDs` \ e' ->
+ returnDs (Let (NonRec n e') body)
+
+dsExpr (HsDoOut do_or_lc stmts return_id then_id fail_id result_ty src_loc)
| maybeToBool maybe_list_comp
= -- Special case for list comprehensions
putSrcLocDs src_loc $
| otherwise
= putSrcLocDs src_loc $
- dsDo do_or_lc stmts return_id then_id zero_id result_ty
+ dsDo do_or_lc stmts return_id then_id fail_id result_ty
where
maybe_list_comp
- = case (do_or_lc, maybeAppTyCon result_ty) of
+ = case (do_or_lc, splitTyConApp_maybe result_ty) of
(ListComp, Just (tycon, [elt_ty]))
| tycon == listTyCon
-> Just elt_ty
dsExpr guard_expr `thenDs` \ core_guard ->
dsExpr then_expr `thenDs` \ core_then ->
dsExpr else_expr `thenDs` \ core_else ->
- returnDs (mkCoreIfThenElse core_guard core_then core_else)
+ returnDs (mkIfThenElse core_guard core_then core_else)
\end{code}
-Type lambda and application
-~~~~~~~~~~~~~~~~~~~~~~~~~~~
+\noindent
+\underline{\bf Type lambda and application}
+% ~~~~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
dsExpr (TyLam tyvars expr)
= dsExpr expr `thenDs` \ core_expr ->
- returnDs (mkTyLam tyvars core_expr)
+ returnDs (mkLams tyvars core_expr)
dsExpr (TyApp expr tys)
= dsExpr expr `thenDs` \ core_expr ->
- returnDs (mkTyApp core_expr tys)
+ returnDs (mkTyApps core_expr tys)
\end{code}
-Various data construction things
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+\noindent
+\underline{\bf Various data construction things}
+% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
dsExpr (ExplicitListOut ty xs)
= 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 [] = returnDs (mkNilExpr 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])
+ returnDs (mkConsExpr ty core_x core_xs)
-dsExpr (ExplicitTuple expr_list)
+dsExpr (ExplicitTuple expr_list boxity)
= mapDs dsExpr expr_list `thenDs` \ core_exprs ->
- mkConDs (tupleCon (length expr_list))
- (map (TyArg . coreExprType) core_exprs ++ map VarArg core_exprs)
+ returnDs (mkConApp (tupleCon boxity (length expr_list))
+ (map (Type . exprType) core_exprs ++ core_exprs))
dsExpr (ArithSeqOut expr (From from))
= dsExpr expr `thenDs` \ expr2 ->
dsExpr from `thenDs` \ from2 ->
- mkAppDs expr2 [VarArg from2]
+ returnDs (App expr2 from2)
dsExpr (ArithSeqOut expr (FromTo from two))
= dsExpr expr `thenDs` \ expr2 ->
dsExpr from `thenDs` \ from2 ->
dsExpr two `thenDs` \ two2 ->
- mkAppDs expr2 [VarArg from2, VarArg two2]
+ returnDs (mkApps expr2 [from2, two2])
dsExpr (ArithSeqOut expr (FromThen from thn))
= dsExpr expr `thenDs` \ expr2 ->
dsExpr from `thenDs` \ from2 ->
dsExpr thn `thenDs` \ thn2 ->
- mkAppDs expr2 [VarArg from2, VarArg thn2]
+ returnDs (mkApps expr2 [from2, thn2])
dsExpr (ArithSeqOut expr (FromThenTo from thn two))
= dsExpr expr `thenDs` \ expr2 ->
dsExpr from `thenDs` \ from2 ->
dsExpr thn `thenDs` \ thn2 ->
dsExpr two `thenDs` \ two2 ->
- mkAppDs expr2 [VarArg from2, VarArg thn2, VarArg two2]
+ returnDs (mkApps expr2 [from2, thn2, two2])
\end{code}
-Record construction and update
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+\noindent
+\underline{\bf Record construction and update}
+% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
For record construction we do this (assuming T has three arguments)
-
+\begin{verbatim}
T { op2 = e }
==>
let err = /\a -> recConErr a
T (recConErr t1 "M.lhs/230/op1")
e
(recConErr t1 "M.lhs/230/op3")
-
-recConErr then converts its arugment string into a proper message
+\end{verbatim}
+@recConErr@ then converts its arugment string into a proper message
before printing it as
-
+\begin{verbatim}
M.lhs, line 230: missing field op1 was evaluated
+\end{verbatim}
+We also handle @C{}@ as valid construction syntax for an unlabelled
+constructor @C@, setting all of @C@'s fields to bottom.
\begin{code}
-dsExpr (RecordConOut con_id con_expr rbinds)
+dsExpr (RecordConOut data_con con_expr rbinds)
= dsExpr con_expr `thenDs` \ con_expr' ->
let
- (arg_tys, _) = splitFunTy (coreExprType con_expr')
+ (arg_tys, _) = splitFunTys (exprType con_expr')
mk_arg (arg_ty, lbl)
= case [rhs | (sel_id,rhs,_) <- rbinds,
lbl == recordSelectorFieldLabel sel_id] of
(rhs:rhss) -> ASSERT( null rhss )
dsExpr rhs
- [] -> mkErrorAppDs rEC_CON_ERROR_ID arg_ty (showForErr lbl)
+ [] -> mkErrorAppDs rEC_CON_ERROR_ID arg_ty (showSDoc (ppr lbl))
+ unlabelled_bottom arg_ty = mkErrorAppDs rEC_CON_ERROR_ID arg_ty ""
+
+ labels = dataConFieldLabels data_con
in
- mapDs mk_arg (zipEqual "dsExpr:RecordCon" arg_tys (dataConFieldLabels con_id)) `thenDs` \ con_args ->
- mkAppDs con_expr' (map VarArg con_args)
+
+ (if null labels
+ then mapDs unlabelled_bottom arg_tys
+ else mapDs mk_arg (zipEqual "dsExpr:RecordCon" arg_tys labels))
+ `thenDs` \ con_args ->
+
+ returnDs (mkApps con_expr' con_args)
\end{code}
Record update is a little harder. Suppose we have the decl:
-
+\begin{verbatim}
data T = T1 {op1, op2, op3 :: Int}
| T2 {op4, op2 :: Int}
| T3
-
+\end{verbatim}
Then we translate as follows:
-
+\begin{verbatim}
r { op2 = e }
===>
let op2 = e in
T1 op1 _ op3 -> T1 op1 op2 op3
T2 op4 _ -> T2 op4 op2
other -> recUpdError "M.lhs/230"
-
-It's important that we use the constructor Ids for T1, T2 etc on the
-RHSs, and do not generate a Core Con directly, because the constructor
+\end{verbatim}
+It's important that we use the constructor Ids for @T1@, @T2@ etc on the
+RHSs, and do not generate a Core constructor application directly, because the constructor
might do some argument-evaluation first; and may have to throw away some
dictionaries.
\begin{code}
dsExpr (RecordUpdOut record_expr record_out_ty dicts rbinds)
- = dsExpr record_expr `thenDs` \ record_expr' ->
+ = getSrcLocDs `thenDs` \ src_loc ->
+ 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_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 out_inst_tys ++ map VarArg dicts
-
- mk_val_arg (field, arg_id)
- = case [arg | (f, arg) <- rbinds',
- field == recordSelectorFieldLabel f] of
- (arg:args) -> ASSERT(null args)
- arg
- [] -> VarArg arg_id
+ record_in_ty = exprType record_expr'
+ (_, in_inst_tys, cons) = splitAlgTyConApp record_in_ty
+ (_, out_inst_tys, _) = splitAlgTyConApp record_out_ty
+ cons_to_upd = filter has_all_fields cons
+
+ mk_val_arg field old_arg_id
+ = case [rhs | (sel_id, rhs, _) <- rbinds,
+ field == recordSelectorFieldLabel sel_id] of
+ (rhs:rest) -> ASSERT(null rest) rhs
+ [] -> HsVar old_arg_id
mk_alt con
= newSysLocalsDs (dataConArgTys con in_inst_tys) `thenDs` \ arg_ids ->
+ -- This call to dataConArgTys won't work for existentials
let
- val_args = map mk_val_arg (zipEqual "dsExpr:RecordUpd" (dataConFieldLabels con) arg_ids)
+ val_args = zipWithEqual "dsExpr:RecordUpd" mk_val_arg
+ (dataConFieldLabels con) arg_ids
+ rhs = foldl HsApp (DictApp (TyApp (HsVar (dataConWrapId con))
+ out_inst_tys)
+ dicts)
+ val_args
in
- returnDs (con, arg_ids, mkGenApp (mkGenApp (Var con) initial_args) val_args)
-
- mk_default
- | length cons_to_upd == length cons
- = returnDs NoDefault
- | otherwise
- = newSysLocalDs record_in_ty `thenDs` \ deflt_id ->
- mkErrorAppDs rEC_UPD_ERROR_ID record_out_ty "" `thenDs` \ err ->
- returnDs (BindDefault deflt_id err)
+ returnDs (mkSimpleMatch [ConPat con record_in_ty [] [] (map VarPat arg_ids)]
+ rhs
+ (Just record_out_ty)
+ src_loc)
in
- mapDs mk_alt cons_to_upd `thenDs` \ alts ->
- mk_default `thenDs` \ deflt ->
+ -- Record stuff doesn't work for existentials
+ ASSERT( all (not . isExistentialDataCon) cons )
- returnDs (Case record_expr' (AlgAlts alts deflt))
+ -- 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) ->
+
+ returnDs (bindNonRec discrim_var record_expr' matching_code)
where
- has_all_fields :: Id -> Bool
+ has_all_fields :: DataCon -> Bool
has_all_fields con_id
= all ok rbinds
where
ok (sel_id, _, _) = recordSelectorFieldLabel sel_id `elem` con_fields
\end{code}
-Dictionary lambda and application
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+\noindent
+\underline{\bf Dictionary lambda and application}
+% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@DictLam@ and @DictApp@ turn into the regular old things.
(OLD:) @DictFunApp@ also becomes a curried application, albeit slightly more
complicated; reminiscent of fully-applied constructors.
\begin{code}
dsExpr (DictLam dictvars expr)
= dsExpr expr `thenDs` \ core_expr ->
- returnDs (mkValLam dictvars core_expr)
+ returnDs (mkLams dictvars core_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)
+ = dsExpr expr `thenDs` \ core_expr ->
+ returnDs (foldl (\f d -> f `App` (Var d)) core_expr 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
- = lookupEnvDs dict `thenDs` \ dict' ->
- returnDs (Var dict')
-
-dsExpr (Dictionary [] []) -- Empty dictionary represented by void,
- = returnDs (Var voidId) -- (not, as would happen if we took the next case, by ())
-
-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 ->
- 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:
dsExpr (ArithSeqIn _) = panic "dsExpr:ArithSeqIn"
#endif
-out_of_range_msg -- ditto
- = " out of range: [" ++ show minInt ++ ", " ++ show maxInt ++ "]\n"
\end{code}
-
%--------------------------------------------------------------------
-\begin{code}
-dsId v
- = lookupEnvDs v `thenDs` \ v' ->
- returnDs (Var v')
-\end{code}
-
-\begin{code}
-dsRbinds :: TypecheckedRecordBinds -- The field bindings supplied
- -> ([(Id, CoreArg)] -> DsM CoreExpr) -- A continuation taking the field
- -- bindings with atomic rhss
- -> DsM CoreExpr -- The result of the continuation,
- -- wrapped in suitable Lets
-
-dsRbinds [] continue_with
- = continue_with []
-
-dsRbinds ((sel_id, rhs, pun_flag) : rbinds) continue_with
- = 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
+dsDo :: StmtCtxt
-> [TypecheckedStmt]
-> Id -- id for: return m
-> Id -- id for: (>>=) m
- -> Id -- id for: zero m
+ -> Id -- id for: fail m
-> Type -- Element type; the whole expression has type (m t)
-> DsM CoreExpr
-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
+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)
go [ReturnStmt expr]
= dsExpr expr `thenDs` \ expr2 ->
- mkAppDs return_ds [TyArg b_ty, VarArg expr2]
+ returnDs (mkApps (Var return_id) [Type b_ty, 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)
+ 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 (coreExprType expr2) -- Must be of form (m a)
+ (_, a_ty) = splitAppTy (exprType 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)]
+ returnDs (mkApps (Var then_id) [Type a_ty, Type b_ty, expr2,
+ Lam ignored_result_id rest])
go (LetStmt binds : stmts )
- = dsBinds False binds `thenDs` \ binds2 ->
- go stmts `thenDs` \ rest ->
- returnDs (mkCoLetsAny binds2 rest)
-
+ = go stmts `thenDs` \ rest ->
+ dsLet binds 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))
+ (_, a_ty) = splitAppTy (exprType expr2) -- Must be of form (m a)
+ 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
the_matches
- = if failureFreePat pat
- then [main_match]
- else [main_match, PatMatch (WildPat a_ty) (SimpleMatch zero_expr)]
+ | failureFreePat pat = [main_match]
+ | otherwise =
+ [ main_match
+ , mkSimpleMatch [WildPat a_ty] fail_expr (Just result_ty) locn
+ ]
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)]
+ returnDs (mkApps (Var then_id) [Type a_ty, Type b_ty, expr2,
+ mkLams binders matching_code])
in
go stmts
DoStmt -> "`do' statement"
ListComp -> "comprehension"
\end{code}
+
+
+%************************************************************************
+%* *
+\subsection[DsExpr-literals]{Literals}
+%* *
+%************************************************************************
+
+We give int/float literals type @Integer@ and @Rational@, respectively.
+The typechecker will (presumably) have put \tr{from{Integer,Rational}s}
+around them.
+
+ToDo: put in range checks for when converting ``@i@''
+(or should that be in the typechecker?)
+
+For numeric literals, we try to detect there use at a standard type
+(@Int@, @Float@, etc.) are directly put in the right constructor.
+[NB: down with the @App@ conversion.]
+
+See also below where we look for @DictApps@ for \tr{plusInt}, etc.
+
+\begin{code}
+dsLit :: HsLit -> DsM CoreExpr
+dsLit (HsChar c) = returnDs (mkConApp charDataCon [mkLit (MachChar c)])
+dsLit (HsCharPrim c) = returnDs (mkLit (MachChar c))
+dsLit (HsString str) = mkStringLitFS str
+dsLit (HsStringPrim s) = returnDs (mkLit (MachStr s))
+dsLit (HsInteger i) = mkIntegerLit i
+dsLit (HsInt i) = returnDs (mkConApp intDataCon [mkIntLit i])
+dsLit (HsIntPrim i) = returnDs (mkIntLit i)
+dsLit (HsFloatPrim f) = returnDs (mkLit (MachFloat f))
+dsLit (HsDoublePrim d) = returnDs (mkLit (MachDouble d))
+dsLit (HsLitLit str ty)
+ = ASSERT( maybeToBool maybe_ty )
+ returnDs (wrap_fn (mkLit (MachLitLit str rep_ty)))
+ where
+ (maybe_ty, wrap_fn) = resultWrapper ty
+ Just rep_ty = maybe_ty
+
+dsLit (HsRat r ty)
+ = mkIntegerLit (numerator r) `thenDs` \ num ->
+ mkIntegerLit (denominator r) `thenDs` \ denom ->
+ returnDs (mkConApp ratio_data_con [Type integer_ty, num, denom])
+ where
+ (ratio_data_con, integer_ty)
+ = case (splitAlgTyConApp_maybe ty) of
+ Just (tycon, [i_ty], [con])
+ -> ASSERT(isIntegerTy i_ty && tycon `hasKey` ratioTyConKey)
+ (con, i_ty)
+
+ _ -> (panic "ratio_data_con", panic "integer_ty")
+\end{code}
+
+
+
projects / ghc-hetmet.git / blobdiff