X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FdeSugar%2FDsExpr.lhs;h=abb2f1e850a6c67af36caa5b2efc852da9bbfc6c;hb=7c72bad588294734ecf3590247c67e47f8ba63fd;hp=2380384ba07bb20265e8cd64e157f54ffeaf3398;hpb=69e14f75a4b031e489b7774914e5a176409cea78;p=ghc-hetmet.git diff --git a/ghc/compiler/deSugar/DsExpr.lhs b/ghc/compiler/deSugar/DsExpr.lhs index 2380384..abb2f1e 100644 --- a/ghc/compiler/deSugar/DsExpr.lhs +++ b/ghc/compiler/deSugar/DsExpr.lhs @@ -11,46 +11,45 @@ module DsExpr ( dsExpr, dsLet ) where import HsSyn ( failureFreePat, HsExpr(..), OutPat(..), HsLit(..), ArithSeqInfo(..), - Stmt(..), StmtCtxt(..), Match(..), HsBinds(..), MonoBinds(..), - mkSimpleMatch + Stmt(..), HsMatchContext(..), Match(..), HsBinds(..), MonoBinds(..), + mkSimpleMatch, isDoExpr ) import TcHsSyn ( TypecheckedHsExpr, TypecheckedHsBinds, - TypecheckedStmt, - maybeBoxedPrimType - + TypecheckedStmt ) import CoreSyn +import CoreUtils ( exprType, mkIfThenElse, bindNonRec ) import DsMonad import DsBinds ( dsMonoBinds, AutoScc(..) ) import DsGRHSs ( dsGuarded ) -import DsCCall ( dsCCall ) +import DsCCall ( dsCCall, resultWrapper ) import DsListComp ( dsListComp ) -import DsUtils ( mkErrorAppDs, mkDsLets, mkConsExpr, mkNilExpr ) +import DsUtils ( mkErrorAppDs, mkDsLets, mkStringLit, mkStringLitFS, + mkConsExpr, mkNilExpr, mkIntegerLit + ) import Match ( matchWrapper, matchSimply ) -import CoreUtils ( coreExprType ) +import FieldLabel ( FieldLabel, fieldLabelTyCon ) import CostCentre ( mkUserCC ) -import FieldLabel ( FieldLabel ) import Id ( Id, idType, recordSelectorFieldLabel ) -import Const ( Con(..) ) -import DataCon ( DataCon, dataConId, dataConTyCon, dataConArgTys, dataConFieldLabels ) -import Const ( mkMachInt, Literal(..), mkStrLit ) -import PrelInfo ( rEC_CON_ERROR_ID, rEC_UPD_ERROR_ID, iRREFUT_PAT_ERROR_ID ) -import TyCon ( isNewTyCon ) +import PrelInfo ( rEC_CON_ERROR_ID, iRREFUT_PAT_ERROR_ID ) +import DataCon ( DataCon, dataConWrapId, dataConArgTys, dataConFieldLabels ) import DataCon ( isExistentialDataCon ) -import Type ( splitFunTys, mkTyConApp, - splitAlgTyConApp, splitTyConApp_maybe, isNotUsgTy, unUsgTy, +import Literal ( Literal(..) ) +import TyCon ( tyConDataCons ) +import Type ( splitFunTys, + splitAlgTyConApp, splitTyConApp_maybe, tyConAppArgs, splitAppTy, isUnLiftedType, Type ) -import TysWiredIn ( tupleCon, unboxedTupleCon, - listTyCon, mkListTy, - charDataCon, charTy, stringTy - ) -import BasicTypes ( RecFlag(..) ) +import TysWiredIn ( tupleCon, listTyCon, charDataCon, intDataCon, isIntegerTy ) +import BasicTypes ( RecFlag(..), Boxity(..) ) import Maybes ( maybeToBool ) +import PrelNames ( hasKey, ratioTyConKey ) import Util ( zipEqual, zipWithEqual ) import Outputable + +import Ratio ( numerator, denominator ) \end{code} @@ -60,14 +59,14 @@ import Outputable %* * %************************************************************************ -@dsLet@ is a match-result transformer, taking the MatchResult for the body +@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. @@ -83,7 +82,8 @@ dsLet (ThenBinds b1 b2) 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 +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 $ @@ -93,10 +93,11 @@ dsLet (MonoBind (AbsBinds [] [] binder_triples inlines (PatMonoBind pat grhss lo 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 + mkErrorAppDs iRREFUT_PAT_ERROR_ID result_ty (showSDoc (ppr pat)) + `thenDs` \ error_expr -> + matchSimply rhs PatBindRhs pat body' error_expr where - result_ty = coreExprType body + result_ty = exprType body -- Ordinary case for bindings dsLet (MonoBind binds sigs is_rec) body @@ -108,140 +109,20 @@ dsLet (MonoBind binds sigs is_rec) body %************************************************************************ %* * -\subsection[DsExpr-vars-and-cons]{Variables and constructors} +\subsection[DsExpr-vars-and-cons]{Variables, constructors, literals} %* * %************************************************************************ \begin{code} dsExpr :: TypecheckedHsExpr -> DsM CoreExpr -dsExpr e@(HsVar var) = returnDs (Var var) -\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.] -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 (mkNilExpr charTy) - - | _LENGTH_ s == 1 - = let - the_char = mkConApp charDataCon [mkLit (MachChar (_HEAD_ s))] - the_nil = mkNilExpr charTy - the_cons = mkConsExpr charTy the_char the_nil - in - returnDs the_cons - - --- "_" => 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 (mkLit (NoRepStr str stringTy)) - -dsExpr (HsLitOut (HsLitLit str) ty) - | isUnLiftedType ty - = returnDs (mkLit (MachLitLit str ty)) - | otherwise - = case (maybeBoxedPrimType ty) of - Just (boxing_data_con, prim_ty) -> - returnDs ( mkConApp boxing_data_con [mkLit (MachLitLit str prim_ty)] ) - _ -> - pprError "ERROR:" - (vcat - [ hcat [ text "Cannot see data constructor of ``literal-literal''s type: " - , text "value:", quotes (quotes (ptext str)) - , text "; type: ", ppr ty - ] - , text "Try compiling with -fno-prune-tydecls." - ]) - - where - (data_con, prim_ty) - = case (maybeBoxedPrimType ty) of - Just (boxing_data_con, prim_ty) -> (boxing_data_con, prim_ty) - Nothing - -> pprPanic "ERROR: ``literal-literal'' not a single-constructor type: " - (hcat [ptext str, text "; type: ", ppr ty]) - -dsExpr (HsLitOut (HsInt i) ty) - = returnDs (mkLit (NoRepInteger i ty)) - -dsExpr (HsLitOut (HsFrac r) ty) - = returnDs (mkLit (NoRepRational r ty)) - --- others where we know what to do: - -dsExpr (HsLitOut (HsIntPrim i) _) - | (i >= toInteger minInt && i <= toInteger maxInt) - = returnDs (mkLit (mkMachInt i)) - | otherwise - = error ("ERROR: Int constant " ++ show i ++ out_of_range_msg) - -dsExpr (HsLitOut (HsFloatPrim f) _) - = returnDs (mkLit (MachFloat f)) - -- ToDo: range checking needed! - -dsExpr (HsLitOut (HsDoublePrim d) _) - = returnDs (mkLit (MachDouble d)) - -- ToDo: range checking needed! - -dsExpr (HsLitOut (HsChar c) _) - = returnDs ( mkConApp charDataCon [mkLit (MachChar c)] ) - -dsExpr (HsLitOut (HsCharPrim c) _) - = returnDs (mkLit (MachChar c)) - -dsExpr (HsLitOut (HsStringPrim s) _) - = returnDs (mkLit (MachStr s)) - --- 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) -> + = matchWrapper LambdaExpr [a_Match] "lambda" `thenDs` \ (binders, matching_code) -> returnDs (mkLams binders matching_code) dsExpr expr@(HsApp fun arg) @@ -284,7 +165,7 @@ 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:_, _) = splitFunTys (coreExprType core_op) + (x_ty:y_ty:_, _) = splitFunTys (exprType core_op) in dsExpr expr `thenDs` \ x_core -> newSysLocalDs x_ty `thenDs` \ x_id -> @@ -298,7 +179,7 @@ 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:_, _) = splitFunTys (coreExprType core_op) + (x_ty:y_ty:_, _) = splitFunTys (exprType core_op) in dsExpr expr `thenDs` \ y_core -> newSysLocalDs x_ty `thenDs` \ x_id -> @@ -307,38 +188,49 @@ dsExpr (SectionR op expr) 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 (Note (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@[Match _ [TuplePat ps boxed] _ _] src_loc) - | not boxed && all var_pat ps +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 "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 (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 "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 @@ -356,8 +248,8 @@ dsExpr (HsDoOut do_or_lc stmts return_id then_id fail_id result_ty src_loc) -> 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 + -- because the interpretation of ExprStmt depends on what sort of thing + -- it is. Just elt_ty = maybe_list_comp @@ -370,8 +262,9 @@ dsExpr (HsIf guard_expr then_expr else_expr src_loc) \end{code} -Type lambda and application -~~~~~~~~~~~~~~~~~~~~~~~~~~~ +\noindent +\underline{\bf Type lambda and application} +% ~~~~~~~~~~~~~~~~~~~~~~~~~~~ \begin{code} dsExpr (TyLam tyvars expr) = dsExpr expr `thenDs` \ core_expr -> @@ -383,40 +276,22 @@ dsExpr (TyApp 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 - go [] = returnDs (mkNilExpr ty) go (x:xs) = dsExpr x `thenDs` \ core_x -> go xs `thenDs` \ core_xs -> - ASSERT( isNotUsgTy ty ) returnDs (mkConsExpr ty core_x core_xs) -dsExpr (ExplicitTuple expr_list boxed) +dsExpr (ExplicitTuple expr_list boxity) = mapDs dsExpr expr_list `thenDs` \ core_exprs -> - returnDs (mkConApp ((if boxed - then tupleCon - else unboxedTupleCon) (length expr_list)) - (map (Type . unUsgTy . coreExprType) core_exprs ++ core_exprs)) - -- the above unUsgTy is *required* -- KSW 1999-04-07 - -dsExpr (HsCon con_id [ty] [arg]) - | isNewTyCon tycon - = dsExpr arg `thenDs` \ arg' -> - returnDs (Note (Coerce result_ty (unUsgTy (coreExprType arg'))) arg') - where - result_ty = mkTyConApp tycon [ty] - tycon = dataConTyCon con_id - -dsExpr (HsCon con_id tys args) - = mapDs dsExpr args `thenDs` \ args2 -> - ASSERT( all isNotUsgTy tys ) - returnDs (mkConApp con_id (map Type tys ++ args2)) + returnDs (mkConApp (tupleCon boxity (length expr_list)) + (map (Type . exprType) core_exprs ++ core_exprs)) dsExpr (ArithSeqOut expr (From from)) = dsExpr expr `thenDs` \ expr2 -> @@ -443,28 +318,32 @@ dsExpr (ArithSeqOut expr (FromThenTo from thn two)) 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 data_con con_expr rbinds) = dsExpr con_expr `thenDs` \ con_expr' -> let - (arg_tys, _) = splitFunTys (coreExprType con_expr') + (arg_tys, _) = splitFunTys (exprType con_expr') mk_arg (arg_ty, lbl) = case [rhs | (sel_id,rhs,_) <- rbinds, @@ -472,19 +351,27 @@ dsExpr (RecordConOut data_con con_expr rbinds) (rhs:rhss) -> ASSERT( null rhss ) dsExpr rhs [] -> 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 data_con)) `thenDs` \ 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 @@ -492,74 +379,85 @@ Then we translate as follows: 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 []) + = dsExpr record_expr + 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 let - ds_rbind (sel_id, rhs, pun_flag) - = dsExpr rhs `thenDs` \ rhs' -> - returnDs (recordSelectorFieldLabel sel_id, rhs') - in - mapDs ds_rbind rbinds `thenDs` \ rbinds' -> - let - 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 Type out_inst_tys ++ map Var dicts - + record_in_ty = exprType record_expr' + in_inst_tys = tyConAppArgs record_in_ty + out_inst_tys = tyConAppArgs record_out_ty + mk_val_arg field old_arg_id - = case [rhs | (f, rhs) <- rbinds', field == f] of + = case [rhs | (sel_id, rhs, _) <- rbinds, + field == recordSelectorFieldLabel sel_id] of (rhs:rest) -> ASSERT(null rest) rhs - [] -> Var old_arg_id + [] -> 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 = zipWithEqual "dsExpr:RecordUpd" mk_val_arg (dataConFieldLabels con) arg_ids - rhs = mkApps (mkApps (Var (dataConId con)) initial_args) val_args + rhs = foldl HsApp (DictApp (TyApp (HsVar (dataConWrapId con)) + out_inst_tys) + dicts) + val_args in - returnDs (DataCon con, arg_ids, rhs) - - mk_default - | length cons_to_upd == length cons - = returnDs [] - | otherwise - = mkErrorAppDs rEC_UPD_ERROR_ID record_out_ty "" `thenDs` \ err -> - returnDs [(DEFAULT, [], err)] + returnDs (mkSimpleMatch [ConPat con record_in_ty [] [] (map VarPat arg_ids)] + rhs + (Just record_out_ty) + src_loc) in -- Record stuff doesn't work for existentials - ASSERT( all (not . isExistentialDataCon) cons ) + ASSERT( all (not . isExistentialDataCon) data_cons ) + + -- 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 RecUpd alts "record update" `thenDs` \ ([discrim_var], matching_code) -> - newSysLocalDs record_in_ty `thenDs` \ case_bndr -> - mapDs mk_alt cons_to_upd `thenDs` \ alts -> - mk_default `thenDs` \ deflt -> + returnDs (bindNonRec discrim_var record_expr' matching_code) - returnDs (Case record_expr' case_bndr (alts ++ deflt)) where + updated_fields :: [FieldLabel] + updated_fields = [recordSelectorFieldLabel sel_id | (sel_id,_,_) <- rbinds] + + -- Get the type constructor from the first field label, + -- so that we are sure it'll have all its DataCons + -- (In GHCI, it's possible that some TyCons may not have all + -- their constructors, in a module-loop situation.) + tycon = fieldLabelTyCon (head updated_fields) + data_cons = tyConDataCons tycon + cons_to_upd = filter has_all_fields data_cons + has_all_fields :: DataCon -> Bool has_all_fields con_id - = all ok rbinds + = all (`elem` con_fields) updated_fields where - con_fields = dataConFieldLabels con_id - ok (sel_id, _, _) = recordSelectorFieldLabel sel_id `elem` con_fields + con_fields = dataConFieldLabels con_id \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. @@ -585,8 +483,6 @@ dsExpr (ExprWithTySig _ _) = panic "dsExpr:ExprWithTySig" dsExpr (ArithSeqIn _) = panic "dsExpr:ArithSeqIn" #endif -out_of_range_msg -- ditto - = " out of range: [" ++ show minInt ++ ", " ++ show maxInt ++ "]\n" \end{code} %-------------------------------------------------------------------- @@ -594,7 +490,7 @@ out_of_range_msg -- ditto Basically does the translation given in the Haskell~1.3 report: \begin{code} -dsDo :: StmtCtxt +dsDo :: HsMatchContext -> [TypecheckedStmt] -> Id -- id for: return m -> Id -- id for: (>>=) m @@ -606,33 +502,36 @@ 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 -> - returnDs (mkApps (Var return_id) [Type b_ty, expr2]) - - go (GuardStmt expr locn : stmts) - = do_expr expr locn `thenDs` \ expr2 -> - go stmts `thenDs` \ rest -> - let msg = ASSERT( isNotUsgTy b_ty ) - "Pattern match failure in do expression, " ++ showSDoc (ppr locn) in - returnDs (mkIfThenElse expr2 - rest - (App (App (Var fail_id) - (Type b_ty)) - (mkLit (mkStrLit msg stringTy)))) - + -- For ExprStmt, see the comments near HsExpr.HsStmt about + -- exactly what ExprStmts mean! + -- + -- In dsDo we can only see DoStmt and ListComp (no gaurds) + + go [ResultStmt expr locn] + | isDoExpr do_or_lc = do_expr expr locn + | otherwise = do_expr expr locn `thenDs` \ expr2 -> + returnDs (mkApps (Var return_id) [Type b_ty, expr2]) + go (ExprStmt expr locn : stmts) + | isDoExpr do_or_lc = do_expr expr locn `thenDs` \ expr2 -> + go stmts `thenDs` \ rest -> + let + (_, a_ty) = splitAppTy (exprType expr2) -- Must be of form (m a) + in + 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 - (_, a_ty) = splitAppTy (coreExprType 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 -> @@ -642,13 +541,13 @@ dsDo do_or_lc stmts return_id then_id fail_id result_ty = putSrcLocDs locn $ dsExpr expr `thenDs` \ expr2 -> let - (_, a_ty) = splitAppTy (coreExprType expr2) -- Must be of form (m a) - fail_expr = HsApp (TyApp (HsVar fail_id) [b_ty]) (HsLitOut (HsString (_PK_ msg)) stringTy) - msg = ASSERT2( isNotUsgTy a_ty, ppr a_ty ) - ASSERT2( isNotUsgTy b_ty, ppr b_ty ) - "Pattern match failure in do expression, " ++ showSDoc (ppr 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) + (HsDoOut do_or_lc stmts return_id then_id + fail_id result_ty locn) (Just result_ty) locn the_matches | failureFreePat pat = [main_match] @@ -657,7 +556,7 @@ dsDo do_or_lc stmts return_id then_id fail_id result_ty , mkSimpleMatch [WildPat a_ty] fail_expr (Just result_ty) locn ] in - matchWrapper DoBindMatch the_matches match_msg + matchWrapper DoExpr the_matches match_msg `thenDs` \ (binders, matching_code) -> returnDs (mkApps (Var then_id) [Type a_ty, Type b_ty, expr2, mkLams binders matching_code]) @@ -668,13 +567,59 @@ dsDo do_or_lc stmts return_id then_id fail_id result_ty do_expr expr locn = putSrcLocDs locn (dsExpr expr) match_msg = case do_or_lc of - DoStmt -> "`do' statement" + DoExpr -> "`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} -var_pat (WildPat _) = True -var_pat (VarPat _) = True -var_pat _ = False +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 ty of + (tycon, [i_ty], [con]) + -> ASSERT(isIntegerTy i_ty && tycon `hasKey` ratioTyConKey) + (con, i_ty) \end{code} + +