X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FdeSugar%2FMatchLit.lhs;h=4a429fe51c1271e44a1eecda5347b243aff4b300;hb=c06cba95f3a44d84b068bbd7af2557134bb8178a;hp=31d8be74cb7727ccb544faad6b7068c41bb18d6a;hpb=e7d21ee4f8ac907665a7e170c71d59e13a01da09;p=ghc-hetmet.git diff --git a/ghc/compiler/deSugar/MatchLit.lhs b/ghc/compiler/deSugar/MatchLit.lhs index 31d8be7..4a429fe 100644 --- a/ghc/compiler/deSugar/MatchLit.lhs +++ b/ghc/compiler/deSugar/MatchLit.lhs @@ -1,29 +1,36 @@ % -% (c) The GRASP/AQUA Project, Glasgow University, 1992-1995 +% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996 % -\section[MatchLit]{Pattern-matching literal and n+k patterns} +\section[MatchLit]{Pattern-matching literal patterns} \begin{code} #include "HsVersions.h" -module MatchLit ( - matchLiterals - ) where - -import AbsSyn -- the stuff being desugared -import PlainCore -- the output of desugaring; - -- importing this module also gets all the - -- CoreSyn utility functions -import DsMonad -- the monadery used in the desugarer - -import AbsUniType ( isPrimType, getUniDataTyCon, kindFromType ) -import BasicLit ( mkMachInt, BasicLit(..), PrimKind ) -import DsExpr ( dsExpr ) +module MatchLit ( matchLiterals ) where + +IMP_Ubiq() +#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ <= 201 +IMPORT_DELOOPER(DsLoop) -- break match-ish and dsExpr-ish loops +#else +import {-# SOURCE #-} Match +import {-# SOURCE #-} DsExpr ( dsExpr ) +#endif + +import HsSyn ( HsLit(..), OutPat(..), HsExpr(..), Fixity, + Match, HsBinds, Stmt(..), DoOrListComp, HsType, ArithSeqInfo ) +import TcHsSyn ( SYN_IE(TypecheckedHsExpr), SYN_IE(TypecheckedHsBinds), + SYN_IE(TypecheckedPat) + ) +import CoreSyn ( SYN_IE(CoreExpr), SYN_IE(CoreBinding), GenCoreExpr(..), GenCoreBinding(..) ) +import Id ( GenId {- instance Eq -}, SYN_IE(Id) ) + +import DsMonad import DsUtils -import Maybes ( Maybe(..), catMaybes ) -import Match ( match ) -import Id ( getIdUniType, eqId ) -import Util + +import Literal ( mkMachInt, Literal(..) ) +import Maybes ( catMaybes ) +import Type ( isPrimType, SYN_IE(Type) ) +import Util ( panic, assertPanic ) \end{code} \begin{code} @@ -50,7 +57,7 @@ matchLiterals all_vars@(var:vars) eqns_info@(EqnInfo (LitPat literal lit_ty : ps where match_prims_used _ [{-no more eqns-}] _ = returnDs [] - match_prims_used vars eqns_info@(EqnInfo ((LitPat literal _):ps1) _ : eqns) shadows + match_prims_used vars eqns_info@(EqnInfo ((LitPat literal lit_ty):ps1) _ : eqns) shadows = let (shifted_eqns_for_this_lit, eqns_not_for_this_lit) = partitionEqnsByLit Nothing literal eqns_info @@ -64,20 +71,20 @@ matchLiterals all_vars@(var:vars) eqns_info@(EqnInfo (LitPat literal lit_ty : ps -- now do the business to make the alt for _this_ LitPat ... match vars shifted_eqns_for_this_lit shifted_shadows_for_this_lit `thenDs` \ match_result -> returnDs ( - (mk_core_lit literal, match_result) + (mk_core_lit lit_ty literal, match_result) : rest_of_alts ) where - mk_core_lit :: Literal -> BasicLit - - mk_core_lit (IntPrimLit i) = mkMachInt i - mk_core_lit (CharPrimLit c) = MachChar c - mk_core_lit (StringPrimLit s) = MachStr s - mk_core_lit (FloatPrimLit f) = MachFloat f - mk_core_lit (DoublePrimLit d) = MachDouble d - mk_core_lit (LitLitLit s t) = ASSERT(isPrimType t) - MachLitLit s (kindFromType t) - mk_core_lit other = panic "matchLiterals:mk_core_lit:unhandled" + mk_core_lit :: Type -> HsLit -> Literal + + mk_core_lit ty (HsIntPrim i) = mkMachInt i + mk_core_lit ty (HsCharPrim c) = MachChar c + mk_core_lit ty (HsStringPrim s) = MachStr s + mk_core_lit ty (HsFloatPrim f) = MachFloat f + mk_core_lit ty (HsDoublePrim d) = MachDouble d + mk_core_lit ty (HsLitLit s) = ASSERT(isPrimType ty) + MachLitLit s (panic "MatchLit.matchLiterals:mk_core_lit:HsLitLit; typePrimRep???") + mk_core_lit ty other = panic "matchLiterals:mk_core_lit:unhandled" \end{code} \begin{code} @@ -86,16 +93,16 @@ matchLiterals all_vars@(var:vars) eqns_info@(EqnInfo ((NPat literal lit_ty eq_ch (shifted_eqns_for_this_lit, eqns_not_for_this_lit) = partitionEqnsByLit Nothing literal eqns_info (shifted_shadows_for_this_lit, shadows_not_for_this_lit) - = partitionEqnsByLit Nothing literal shadows + = partitionEqnsByLit Nothing literal shadows in - dsExpr (App eq_chk (Var var)) `thenDs` \ pred_expr -> + dsExpr (HsApp eq_chk (HsVar var)) `thenDs` \ pred_expr -> match vars shifted_eqns_for_this_lit shifted_shadows_for_this_lit `thenDs` \ inner_match_result -> mkGuardedMatchResult pred_expr inner_match_result `thenDs` \ match_result1 -> if (null eqns_not_for_this_lit) - then + then returnDs match_result1 - else + else matchLiterals all_vars eqns_not_for_this_lit shadows_not_for_this_lit `thenDs` \ match_result2 -> combineMatchResults match_result1 match_result2 \end{code} @@ -110,8 +117,9 @@ We generate: \end{verbatim} + \begin{code} -matchLiterals all_vars@(var:vars) eqns_info@(EqnInfo ((NPlusKPat master_n k ty from_lit ge sub):ps1) _ : eqns) shadows +matchLiterals all_vars@(var:vars) eqns_info@(EqnInfo ((NPlusKPat master_n k ty ge sub):ps1) _ : eqns) shadows = let (shifted_eqns_for_this_lit, eqns_not_for_this_lit) = partitionEqnsByLit (Just master_n) k eqns_info @@ -120,15 +128,12 @@ matchLiterals all_vars@(var:vars) eqns_info@(EqnInfo ((NPlusKPat master_n k ty f in match vars shifted_eqns_for_this_lit shifted_shadows_for_this_lit `thenDs` \ inner_match_result -> - dsExpr from_lit `thenDs` \ core_lit -> - dsExpr (App ge (Var var)) `thenDs` \ var_ge -> - dsExpr (App sub (Var var)) `thenDs` \ var_sub -> - mkCoAppDs var_ge core_lit `thenDs` \ var_ge_lit -> - mkCoAppDs var_sub core_lit `thenDs` \ var_sub_lit -> + dsExpr (HsApp ge (HsVar var)) `thenDs` \ ge_expr -> + dsExpr (HsApp sub (HsVar var)) `thenDs` \ nminusk_expr -> mkGuardedMatchResult - var_ge_lit - (mkCoLetsMatchResult [CoNonRec master_n var_sub_lit] inner_match_result) + ge_expr + (mkCoLetsMatchResult [NonRec master_n nminusk_expr] inner_match_result) `thenDs` \ match_result1 -> if (null eqns_not_for_this_lit) @@ -139,16 +144,15 @@ matchLiterals all_vars@(var:vars) eqns_info@(EqnInfo ((NPlusKPat master_n k ty f combineMatchResults match_result1 match_result2 \end{code} -Given a blob of LitPats/NPats/NPlusKPats, we want to split them into those +Given a blob of LitPats/NPats, we want to split them into those that are ``same''/different as one we are looking at. We need to know -whether we're looking at a LitPat/NPat or NPlusKPat (initial Bool arg is -@True@ for the latter), and what literal we're after. +whether we're looking at a LitPat/NPat, and what literal we're after. \begin{code} -partitionEqnsByLit :: Maybe Id -- (Just v) for N-plus-K patterns, where v +partitionEqnsByLit :: Maybe Id -- (Just v) for N-plus-K patterns, where v -- is the "master" variable; -- Nothing for NPats and LitPats - -> Literal + -> HsLit -> [EquationInfo] -> ([EquationInfo], -- These ones are for this lit, AND -- they've been "shifted" by stripping @@ -157,49 +161,47 @@ partitionEqnsByLit :: Maybe Id -- (Just v) for N-plus-K patterns, where v -- are exactly as fed in. ) -partitionEqnsByLit want_NPlusK lit eqns +partitionEqnsByLit nPlusK lit eqns = ( \ (xs,ys) -> (catMaybes xs, catMaybes ys)) - (unzip (map (partition_eqn want_NPlusK lit) eqns)) + (unzip (map (partition_eqn nPlusK lit) eqns)) where - partition_eqn :: Maybe Id -> Literal -> EquationInfo -> + partition_eqn :: Maybe Id -> HsLit -> EquationInfo -> (Maybe EquationInfo, Maybe EquationInfo) partition_eqn Nothing lit (EqnInfo (LitPat k _ : remaining_pats) match_result) | lit `eq_lit` k = (Just (EqnInfo remaining_pats match_result), Nothing) - -- NB the pattern is stripped off thhe EquationInfo + -- NB the pattern is stripped off the EquationInfo partition_eqn Nothing lit (EqnInfo (NPat k _ _ : remaining_pats) match_result) | lit `eq_lit` k = (Just (EqnInfo remaining_pats match_result), Nothing) - -- NB the pattern is stripped off thhe EquationInfo + -- NB the pattern is stripped off the EquationInfo - partition_eqn (Just master_n) lit (EqnInfo (NPlusKPat n k _ _ _ _ : remaining_pats) match_result) + partition_eqn (Just master_n) lit (EqnInfo (NPlusKPat n k _ _ _ : remaining_pats) match_result) | lit `eq_lit` k = (Just (EqnInfo remaining_pats new_match_result), Nothing) - -- NB the pattern is stripped off thhe EquationInfo + -- NB the pattern is stripped off the EquationInfo where - new_match_result = if master_n `eqId` n then - match_result - else - mkCoLetsMatchResult [CoNonRec n (CoVar master_n)] match_result + new_match_result | master_n == n = match_result + | otherwise = mkCoLetsMatchResult [NonRec n (Var master_n)] match_result -- Wild-card patterns, which will only show up in the shadows, go into both groups - partition_eqn wantNPlusK lit eqn@(EqnInfo (WildPat _ : remaining_pats) match_result) + partition_eqn nPlusK lit eqn@(EqnInfo (WildPat _ : remaining_pats) match_result) = (Just (EqnInfo remaining_pats match_result), Just eqn) -- Default case; not for this pattern - partition_eqn wantNPlusK lit eqn = (Nothing, Just eqn) + partition_eqn nPlusK lit eqn = (Nothing, Just eqn) -- ToDo: meditate about this equality business... -eq_lit (IntLit i1) (IntLit i2) = i1 == i2 -eq_lit (FracLit f1) (FracLit f2) = f1 == f2 - -eq_lit (IntPrimLit i1) (IntPrimLit i2) = i1 == i2 -eq_lit (FloatPrimLit f1) (FloatPrimLit f2) = f1 == f2 -eq_lit (DoublePrimLit d1) (DoublePrimLit d2) = d1 == d2 -eq_lit (CharLit c1) (CharLit c2) = c1 == c2 -eq_lit (CharPrimLit c1) (CharPrimLit c2) = c1 == c2 -eq_lit (StringLit s1) (StringLit s2) = s1 == s2 -eq_lit (StringPrimLit s1) (StringPrimLit s2) = s1 == s2 -eq_lit (LitLitLit s1 _) (LitLitLit s2 _) = s1 == s2 -- ToDo: ??? (dubious) -eq_lit other1 other2 = panic "matchLiterals:eq_lit" +eq_lit (HsInt i1) (HsInt i2) = i1 == i2 +eq_lit (HsFrac f1) (HsFrac f2) = f1 == f2 + +eq_lit (HsIntPrim i1) (HsIntPrim i2) = i1 == i2 +eq_lit (HsFloatPrim f1) (HsFloatPrim f2) = f1 == f2 +eq_lit (HsDoublePrim d1) (HsDoublePrim d2) = d1 == d2 +eq_lit (HsChar c1) (HsChar c2) = c1 == c2 +eq_lit (HsCharPrim c1) (HsCharPrim c2) = c1 == c2 +eq_lit (HsString s1) (HsString s2) = s1 == s2 +eq_lit (HsStringPrim s1) (HsStringPrim s2) = s1 == s2 +eq_lit (HsLitLit s1) (HsLitLit s2) = s1 == s2 -- ToDo: ??? (dubious) +eq_lit other1 other2 = panic "matchLiterals:eq_lit" \end{code}