X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FdeSugar%2FDsExpr.lhs;h=2865f948700cbc56dc66fe7c684507c3262e85a6;hb=fa6b1e4523a9d8a1fe85a95e5c69e767746cbe7d;hp=a207c4d7ca371e4a2f774292fa2874c2dbbbdca7;hpb=b2f644fa8edcf8697640c9228089b39030b8b362;p=ghc-hetmet.git diff --git a/ghc/compiler/deSugar/DsExpr.lhs b/ghc/compiler/deSugar/DsExpr.lhs index a207c4d..2865f94 100644 --- a/ghc/compiler/deSugar/DsExpr.lhs +++ b/ghc/compiler/deSugar/DsExpr.lhs @@ -4,18 +4,35 @@ \section[DsExpr]{Matching expressions (Exprs)} \begin{code} -module DsExpr ( dsExpr, dsLet ) where +module DsExpr ( dsExpr, dsLet, dsLit ) where #include "HsVersions.h" -import HsSyn ( failureFreePat, - HsExpr(..), OutPat(..), HsLit(..), ArithSeqInfo(..), - Stmt(..), HsMatchContext(..), HsDoContext(..), - Match(..), HsBinds(..), MonoBinds(..), - mkSimpleMatch +import Match ( matchWrapper, matchSimply ) +import MatchLit ( dsLit ) +import DsBinds ( dsMonoBinds, AutoScc(..) ) +import DsGRHSs ( dsGuarded ) +import DsCCall ( dsCCall ) +import DsListComp ( dsListComp, dsPArrComp ) +import DsUtils ( mkErrorAppDs, mkStringLit, mkConsExpr, mkNilExpr, + mkCoreTupTy, selectMatchVar, + dsReboundNames, lookupReboundName ) +import DsArrows ( dsProcExpr ) +import DsMonad + +#ifdef GHCI + -- Template Haskell stuff iff bootstrapped +import DsMeta ( dsBracket, dsReify ) +#endif + +import HsSyn ( HsExpr(..), Pat(..), ArithSeqInfo(..), + Stmt(..), HsMatchContext(..), HsStmtContext(..), + Match(..), HsBinds(..), MonoBinds(..), HsConDetails(..), + ReboundNames, + mkSimpleMatch, isDoExpr ) -import TcHsSyn ( TypecheckedHsExpr, TypecheckedHsBinds, TypecheckedStmt, outPatType ) +import TcHsSyn ( TypecheckedHsExpr, TypecheckedHsBinds, TypecheckedStmt, hsPatType ) -- NB: The desugarer, which straddles the source and Core worlds, sometimes -- needs to see source types (newtypes etc), and sometimes not @@ -23,38 +40,29 @@ import TcHsSyn ( TypecheckedHsExpr, TypecheckedHsBinds, TypecheckedStmt, outPat -- Sigh. This is a pain. import TcType ( tcSplitAppTy, tcSplitFunTys, tcTyConAppArgs, - isIntegerTy, tcSplitTyConApp, isUnLiftedType, Type ) + tcSplitTyConApp, isUnLiftedType, Type, + mkAppTy ) import Type ( splitFunTys ) import CoreSyn import CoreUtils ( exprType, mkIfThenElse, bindNonRec ) -import DsMonad -import DsBinds ( dsMonoBinds, AutoScc(..) ) -import DsGRHSs ( dsGuarded ) -import DsCCall ( dsCCall, resultWrapper ) -import DsListComp ( dsListComp, dsPArrComp ) -import DsUtils ( mkErrorAppDs, mkStringLit, mkStringLitFS, - mkConsExpr, mkNilExpr, mkIntegerLit - ) -import Match ( matchWrapper, matchSimply ) - import FieldLabel ( FieldLabel, fieldLabelTyCon ) import CostCentre ( mkUserCC ) -import Id ( Id, idType, recordSelectorFieldLabel ) +import Id ( Id, idType, idName, recordSelectorFieldLabel ) import PrelInfo ( rEC_CON_ERROR_ID, iRREFUT_PAT_ERROR_ID ) import DataCon ( DataCon, dataConWrapId, dataConFieldLabels, dataConInstOrigArgTys ) import DataCon ( isExistentialDataCon ) -import Literal ( Literal(..) ) +import Name ( Name ) import TyCon ( tyConDataCons ) -import TysWiredIn ( tupleCon, charDataCon, intDataCon ) +import TysWiredIn ( tupleCon, mkTupleTy ) import BasicTypes ( RecFlag(..), Boxity(..), ipNameName ) -import Maybes ( maybeToBool ) -import PrelNames ( hasKey, ratioTyConKey, toPName ) +import PrelNames ( toPName, + returnMName, bindMName, thenMName, failMName, + mfixName ) +import SrcLoc ( noSrcLoc ) import Util ( zipEqual, zipWithEqual ) import Outputable import FastString - -import Ratio ( numerator, denominator ) \end{code} @@ -85,6 +93,13 @@ dsLet (ThenBinds b1 b2) body = dsLet b2 body `thenDs` \ body' -> dsLet b1 body' +dsLet (IPBinds binds is_with) body + = foldlDs dsIPBind body binds + where + dsIPBind body (n, e) + = dsExpr e `thenDs` \ e' -> + returnDs (Let (NonRec (ipNameName n) e') 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. @@ -100,8 +115,8 @@ dsLet bind@(MonoBind (AbsBinds [] [] exports inlines binds) sigs is_rec) body -- below. Then pattern-match would fail. Urk.) case binds of FunMonoBind fun _ matches loc - -> putSrcLocDs loc $ - matchWrapper (FunRhs fun) matches `thenDs` \ (args, rhs) -> + -> putSrcLocDs loc $ + matchWrapper (FunRhs (idName fun)) matches `thenDs` \ (args, rhs) -> ASSERT( null args ) -- Functions aren't lifted returnDs (bindNonRec fun rhs body_w_exports) @@ -146,6 +161,7 @@ dsLet (MonoBind binds sigs is_rec) body \begin{code} dsExpr :: TypecheckedHsExpr -> DsM CoreExpr +dsExpr (HsPar x) = dsExpr x dsExpr (HsVar var) = returnDs (Var var) dsExpr (HsIPVar ip) = returnDs (Var (ipNameName ip)) dsExpr (HsLit lit) = dsLit lit @@ -230,6 +246,13 @@ dsExpr (HsSCC cc expr) getModuleDs `thenDs` \ mod_name -> returnDs (Note (SCC (mkUserCC cc mod_name)) core_expr) + +-- hdaume: core annotation + +dsExpr (HsCoreAnn fs expr) + = dsExpr expr `thenDs` \ core_expr -> + returnDs (Note (CoreNote $ unpackFS fs) core_expr) + -- special case to handle unboxed tuple patterns. dsExpr (HsCase discrim matches src_loc) @@ -255,14 +278,6 @@ dsExpr (HsLet binds body) = dsExpr body `thenDs` \ body' -> dsLet binds body' -dsExpr (HsWith expr binds is_with) - = dsExpr expr `thenDs` \ expr' -> - foldlDs dsIPBind expr' binds - where - dsIPBind body (n, e) - = dsExpr e `thenDs` \ e' -> - returnDs (Let (NonRec (ipNameName n) e') body) - -- 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. -- @@ -273,9 +288,10 @@ dsExpr (HsDo ListComp stmts _ result_ty src_loc) where (_, [elt_ty]) = tcSplitTyConApp result_ty -dsExpr (HsDo DoExpr stmts ids result_ty src_loc) +dsExpr (HsDo do_or_lc stmts ids result_ty src_loc) + | isDoExpr do_or_lc = putSrcLocDs src_loc $ - dsDo DoExpr stmts ids result_ty + dsDo do_or_lc stmts ids result_ty dsExpr (HsDo PArrComp stmts _ result_ty src_loc) = -- Special case for array comprehensions @@ -330,7 +346,7 @@ dsExpr (ExplicitList ty xs) -- here at compile time -- dsExpr (ExplicitPArr ty xs) - = dsLookupGlobalValue toPName `thenDs` \toP -> + = dsLookupGlobalId toPName `thenDs` \toP -> dsExpr (ExplicitList ty xs) `thenDs` \coreList -> returnDs (mkApps (Var toP) [Type ty, coreList]) @@ -412,7 +428,7 @@ dsExpr (RecordConOut data_con con_expr rbinds) -- hence TcType.tcSplitFunTys mk_arg (arg_ty, lbl) - = case [rhs | (sel_id,rhs,_) <- rbinds, + = case [rhs | (sel_id,rhs) <- rbinds, lbl == recordSelectorFieldLabel sel_id] of (rhs:rhss) -> ASSERT( null rhss ) dsExpr rhs @@ -467,7 +483,7 @@ dsExpr expr@(RecordUpdOut record_expr record_in_ty record_out_ty rbinds) out_inst_tys = tcTyConAppArgs record_out_ty -- Newtype opaque mk_val_arg field old_arg_id - = case [rhs | (sel_id, rhs, _) <- rbinds, + = case [rhs | (sel_id, rhs) <- rbinds, field == recordSelectorFieldLabel sel_id] of (rhs:rest) -> ASSERT(null rest) rhs [] -> HsVar old_arg_id @@ -481,7 +497,7 @@ dsExpr expr@(RecordUpdOut record_expr record_in_ty record_out_ty rbinds) rhs = foldl HsApp (TyApp (HsVar (dataConWrapId con)) out_inst_tys) val_args in - returnDs (mkSimpleMatch [ConPat con record_in_ty [] [] (map VarPat arg_ids)] + returnDs (mkSimpleMatch [ConPatOut con (PrefixCon (map VarPat arg_ids)) record_in_ty [] []] rhs record_out_ty src_loc) @@ -502,7 +518,7 @@ dsExpr expr@(RecordUpdOut record_expr record_in_ty record_out_ty rbinds) where updated_fields :: [FieldLabel] - updated_fields = [recordSelectorFieldLabel sel_id | (sel_id,_,_) <- rbinds] + 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 @@ -538,6 +554,22 @@ dsExpr (DictApp expr dicts) -- becomes a curried application returnDs (foldl (\f d -> f `App` (Var d)) core_expr dicts) \end{code} +Here is where we desugar the Template Haskell brackets and escapes + +\begin{code} +-- Template Haskell stuff + +#ifdef GHCI /* Only if bootstrapping */ +dsExpr (HsBracketOut x ps) = dsBracket x ps +dsExpr (HsReify r) = dsReify r +dsExpr (HsSplice n e _) = pprPanic "dsExpr:splice" (ppr e) +#endif + +-- Arrow notation extension +dsExpr (HsProc pat cmd src_loc) = dsProcExpr pat cmd src_loc +\end{code} + + \begin{code} #ifdef DEBUG @@ -554,18 +586,22 @@ dsExpr (PArrSeqIn _) = panic "dsExpr:PArrSeqIn" Basically does the translation given in the Haskell~1.3 report: \begin{code} -dsDo :: HsDoContext +dsDo :: HsStmtContext Name -> [TypecheckedStmt] - -> [Id] -- id for: [return,fail,>>=,>>] - -> Type -- Element type; the whole expression has type (m t) + -> ReboundNames Id -- id for: [return,fail,>>=,>>] and possibly mfixName + -> Type -- Element type; the whole expression has type (m t) -> DsM CoreExpr -dsDo do_or_lc stmts ids@[return_id, fail_id, bind_id, then_id] result_ty - = let - (_, b_ty) = tcSplitAppTy result_ty -- result_ty must be of the form (m b) - is_do = case do_or_lc of - DoExpr -> True - _ -> False +dsDo do_or_lc stmts ids result_ty + = dsReboundNames ids `thenDs` \ (meth_binds, ds_meths) -> + let + return_id = lookupReboundName ds_meths returnMName + fail_id = lookupReboundName ds_meths failMName + bind_id = lookupReboundName ds_meths bindMName + then_id = lookupReboundName ds_meths thenMName + + (m_ty, b_ty) = tcSplitAppTy result_ty -- result_ty must be of the form (m b) + is_do = isDoExpr do_or_lc -- True for both MDo and Do -- For ExprStmt, see the comments near HsExpr.Stmt about -- exactly what ExprStmts mean! @@ -575,13 +611,13 @@ dsDo do_or_lc stmts ids@[return_id, fail_id, bind_id, then_id] result_ty 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]) + returnDs (mkApps 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 -> - returnDs (mkApps (Var then_id) [Type a_ty, Type b_ty, expr2, rest]) + returnDs (mkApps then_id [Type a_ty, Type b_ty, expr2, rest]) | otherwise -- List comprehension = do_expr expr locn `thenDs` \ expr2 -> @@ -591,85 +627,81 @@ dsDo do_or_lc stmts ids@[return_id, fail_id, bind_id, then_id] result_ty in mkStringLit msg `thenDs` \ core_msg -> returnDs (mkIfThenElse expr2 rest - (App (App (Var fail_id) (Type b_ty)) core_msg)) + (App (App fail_id (Type b_ty)) core_msg)) - go (LetStmt binds : stmts ) + go (LetStmt binds : stmts) = go stmts `thenDs` \ rest -> dsLet binds rest go (BindStmt pat expr locn : stmts) - = putSrcLocDs locn $ - dsExpr expr `thenDs` \ expr2 -> + = go stmts `thenDs` \ body -> + putSrcLocDs locn $ -- Rest is associated with this location + dsExpr expr `thenDs` \ rhs -> + mkStringLit (mk_msg locn) `thenDs` \ core_msg -> let - a_ty = outPatType pat - fail_expr = HsApp (TyApp (HsVar fail_id) [b_ty]) - (HsLit (HsString (mkFastString msg))) - msg = "Pattern match failure in do expression, " ++ showSDoc (ppr locn) - main_match = mkSimpleMatch [pat] - (HsDo do_or_lc stmts ids result_ty locn) - result_ty locn - the_matches - | failureFreePat pat = [main_match] - | otherwise = - [ main_match - , mkSimpleMatch [WildPat a_ty] fail_expr result_ty locn - ] + -- In a do expression, pattern-match failure just calls + -- the monadic 'fail' rather than throwing an exception + fail_expr = mkApps fail_id [Type b_ty, core_msg] + a_ty = hsPatType pat in - matchWrapper (DoCtxt do_or_lc) the_matches `thenDs` \ (binders, matching_code) -> - returnDs (mkApps (Var bind_id) [Type a_ty, Type b_ty, expr2, - mkLams binders matching_code]) + selectMatchVar pat `thenDs` \ var -> + matchSimply (Var var) (StmtCtxt do_or_lc) pat + body fail_expr `thenDs` \ match_code -> + returnDs (mkApps bind_id [Type a_ty, Type b_ty, rhs, Lam var match_code]) + + go (RecStmt rec_stmts later_vars rec_vars rec_rets : stmts) + = go (bind_stmt : stmts) + where + bind_stmt = dsRecStmt m_ty ds_meths rec_stmts later_vars rec_vars rec_rets + in - go stmts + go stmts `thenDs` \ stmts_code -> + returnDs (foldr Let stmts_code meth_binds) where do_expr expr locn = putSrcLocDs locn (dsExpr expr) + mk_msg locn = "Pattern match failure in do expression at " ++ showSDoc (ppr locn) \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. +Translation for RecStmt's: +----------------------------- +We turn (RecStmt [v1,..vn] stmts) into: + + (v1,..,vn) <- mfix (\~(v1,..vn). do stmts + return (v1,..vn)) \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 tcSplitTyConApp ty of - (tycon, [i_ty]) -> ASSERT(isIntegerTy i_ty && tycon `hasKey` ratioTyConKey) - (head (tyConDataCons tycon), i_ty) +dsRecStmt :: Type -- Monad type constructor :: * -> * + -> [(Name,Id)] -- Rebound Ids + -> [TypecheckedStmt] + -> [Id] -> [Id] -> [TypecheckedHsExpr] + -> TypecheckedStmt +dsRecStmt m_ty ds_meths stmts later_vars rec_vars rec_rets + = ASSERT( length vars == length rets ) + BindStmt tup_pat mfix_app noSrcLoc + where + vars@(var1:rest) = later_vars ++ rec_vars -- Always at least one + rets@(ret1:_) = map HsVar later_vars ++ rec_rets + one_var = null rest + + mfix_app = HsApp (TyApp (HsVar mfix_id) [tup_ty]) mfix_arg + mfix_arg = HsLam (mkSimpleMatch [tup_pat] body tup_ty noSrcLoc) + + tup_expr | one_var = ret1 + | otherwise = ExplicitTuple rets Boxed + tup_ty = mkCoreTupTy (map idType vars) + -- Deals with singleton case + tup_pat | one_var = VarPat var1 + | otherwise = LazyPat (TuplePat (map VarPat vars) Boxed) + + body = HsDo DoExpr (stmts ++ [return_stmt]) + [(n, HsVar id) | (n,id) <- ds_meths] -- A bit of a hack + (mkAppTy m_ty tup_ty) + noSrcLoc + + Var return_id = lookupReboundName ds_meths returnMName + Var mfix_id = lookupReboundName ds_meths mfixName + + return_stmt = ResultStmt return_app noSrcLoc + return_app = HsApp (TyApp (HsVar return_id) [tup_ty]) tup_expr \end{code}