module DsUtils (
EquationInfo(..),
firstPat, shiftEqns,
-
- mkDsLet,
+
+ mkDsLet, mkDsLets,
MatchResult(..), CanItFail(..),
cantFailMatchResult, alwaysFailMatchResult,
extractMatchResult, combineMatchResults,
adjustMatchResult, adjustMatchResultDs,
- mkCoLetsMatchResult, mkCoLetMatchResult,
- mkGuardedMatchResult,
+ mkCoLetMatchResult, mkGuardedMatchResult,
+ matchCanFail,
mkCoPrimCaseMatchResult, mkCoAlgCaseMatchResult,
- bindInMatchResult, bindOneInMatchResult,
+ wrapBind, wrapBinds,
mkErrorAppDs, mkNilExpr, mkConsExpr, mkListExpr,
mkIntExpr, mkCharExpr,
mkTupleType, mkTupleCase, mkBigCoreTup,
mkCoreTup, mkCoreTupTy,
- dsReboundNames, lookupReboundName,
+ dsSyntaxTable, lookupEvidence,
selectSimpleMatchVarL, selectMatchVars
) where
import Name ( Name )
import Literal ( Literal(..), mkStringLit, inIntRange, tARGET_MAX_INT )
import TyCon ( isNewTyCon, tyConDataCons )
-import DataCon ( DataCon, dataConSourceArity, dataConTyCon )
+import DataCon ( DataCon, dataConSourceArity, dataConTyCon, dataConTag )
import Type ( mkFunTy, isUnLiftedType, Type, splitTyConApp, mkTyVarTy )
-import TcType ( tcTyConAppTyCon, tcEqType )
+import TcType ( tcEqType )
import TysPrim ( intPrimTy )
import TysWiredIn ( nilDataCon, consDataCon,
tupleCon, mkTupleTy,
plusIntegerName, timesIntegerName, smallIntegerDataConName,
lengthPName, indexPName )
import Outputable
-import UnicodeUtil ( intsToUtf8 )
-import SrcLoc ( Located(..), unLoc, noLoc )
-import Util ( isSingleton, notNull, zipEqual )
+import SrcLoc ( Located(..), unLoc )
+import Util ( isSingleton, zipEqual, sortWith )
import ListSetOps ( assocDefault )
import FastString
+import Data.Char ( ord )
+
+#ifdef DEBUG
+import Util ( notNull ) -- Used in an assertion
+#endif
\end{code}
%************************************************************************
\begin{code}
-dsReboundNames :: ReboundNames Id
+dsSyntaxTable :: SyntaxTable Id
-> DsM ([CoreBind], -- Auxiliary bindings
[(Name,Id)]) -- Maps the standard name to its value
-dsReboundNames rebound_ids
+dsSyntaxTable rebound_ids
= mapAndUnzipDs mk_bind rebound_ids `thenDs` \ (binds_s, prs) ->
return (concat binds_s, prs)
where
newSysLocalDs (exprType rhs) `thenDs` \ id ->
return ([NonRec id rhs], (std_name, id))
-lookupReboundName :: [(Name,Id)] -> Name -> CoreExpr
-lookupReboundName prs std_name
- = Var (assocDefault (mk_panic std_name) prs std_name)
+lookupEvidence :: [(Name, Id)] -> Name -> Id
+lookupEvidence prs std_name
+ = assocDefault (mk_panic std_name) prs std_name
where
- mk_panic std_name = pprPanic "dsReboundNames" (ptext SLIT("Not found:") <+> ppr std_name)
+ mk_panic std_name = pprPanic "dsSyntaxTable" (ptext SLIT("Not found:") <+> ppr std_name)
\end{code}
worthy of a type synonym and a few handy functions.
\begin{code}
-data EquationInfo
- = EqnInfo { eqn_pats :: [Pat Id], -- The patterns for an eqn
- eqn_rhs :: MatchResult } -- What to do after match
-
--- The semantics of (match vs (EqnInfo wrap pats rhs)) is the MatchResult
--- \fail. wrap (case vs of { pats -> rhs fail })
--- where vs are not in the domain of wrap
-
firstPat :: EquationInfo -> Pat Id
firstPat eqn = head (eqn_pats eqn)
shiftEqns :: [EquationInfo] -> [EquationInfo]
--- Drop the outermost layer of the first pattern in each equation
-shiftEqns eqns = [ eqn { eqn_pats = shiftPats (eqn_pats eqn) }
- | eqn <- eqns ]
-
-shiftPats :: [Pat Id] -> [Pat Id]
-shiftPats (ConPatOut _ _ _ _ (PrefixCon arg_pats) _ : pats) = map unLoc arg_pats ++ pats
-shiftPats (pat_with_no_sub_pats : pats) = pats
-\end{code}
-
-
-\begin{code}
--- A MatchResult is an expression with a hole in it
-data MatchResult
- = MatchResult
- CanItFail -- Tells whether the failure expression is used
- (CoreExpr -> DsM CoreExpr)
- -- Takes a expression to plug in at the
- -- failure point(s). The expression should
- -- be duplicatable!
-
-data CanItFail = CanFail | CantFail
-
-orFail CantFail CantFail = CantFail
-orFail _ _ = CanFail
+-- Drop the first pattern in each equation
+shiftEqns eqns = [ eqn { eqn_pats = tail (eqn_pats eqn) } | eqn <- eqns ]
\end{code}
Functions on MatchResults
\begin{code}
+matchCanFail :: MatchResult -> Bool
+matchCanFail (MatchResult CanFail _) = True
+matchCanFail (MatchResult CantFail _) = False
+
alwaysFailMatchResult :: MatchResult
alwaysFailMatchResult = MatchResult CanFail (\fail -> returnDs fail)
= MatchResult can_it_fail (\fail -> body_fn fail `thenDs` \ body ->
encl_fn body)
-bindInMatchResult :: [(Var,Var)] -> MatchResult -> MatchResult
-bindInMatchResult binds = adjustMatchResult (\e -> foldr bind e binds)
- where
- bind (new,old) body = bindMR new old body
+wrapBinds :: [(Var,Var)] -> CoreExpr -> CoreExpr
+wrapBinds [] e = e
+wrapBinds ((new,old):prs) e = wrapBind new old (wrapBinds prs e)
-bindOneInMatchResult :: Var -> Var -> MatchResult -> MatchResult
-bindOneInMatchResult new old = adjustMatchResult (bindMR new old)
-
-bindMR :: Var -> Var -> CoreExpr -> CoreExpr
-bindMR new old body
+wrapBind :: Var -> Var -> CoreExpr -> CoreExpr
+wrapBind new old body
| new==old = body
| isTyVar new = App (Lam new body) (Type (mkTyVarTy old))
| otherwise = Let (NonRec new (Var old)) body
-mkCoLetsMatchResult :: [CoreBind] -> MatchResult -> MatchResult
-mkCoLetsMatchResult binds match_result
- = adjustMatchResult (mkDsLets binds) match_result
-
mkCoLetMatchResult :: CoreBind -> MatchResult -> MatchResult
mkCoLetMatchResult bind match_result
= adjustMatchResult (mkDsLet bind) match_result
= MatchResult CanFail mk_case
where
mk_case fail
- = mappM (mk_alt fail) match_alts `thenDs` \ alts ->
+ = mappM (mk_alt fail) sorted_alts `thenDs` \ alts ->
returnDs (Case (Var var) var ty ((DEFAULT, [], fail) : alts))
+ sorted_alts = sortWith fst match_alts -- Right order for a Case
mk_alt fail (lit, MatchResult _ body_fn) = body_fn fail `thenDs` \ body ->
returnDs (LitAlt lit, [], body)
mkCoAlgCaseMatchResult var ty match_alts
| isNewTyCon tycon -- Newtype case; use a let
= ASSERT( null (tail match_alts) && null (tail arg_ids1) )
- mkCoLetsMatchResult [NonRec arg_id1 newtype_rhs] match_result1
+ mkCoLetMatchResult (NonRec arg_id1 newtype_rhs) match_result1
| isPArrFakeAlts match_alts -- Sugared parallel array; use a literal case
= MatchResult CanFail mk_parrCase
= CanFail
wild_var = mkWildId (idType var)
- mk_case fail = mappM (mk_alt fail) match_alts `thenDs` \ alts ->
+ sorted_alts = sortWith get_tag match_alts
+ get_tag (con, _, _) = dataConTag con
+ mk_case fail = mappM (mk_alt fail) sorted_alts `thenDs` \ alts ->
returnDs (Case (Var var) wild_var ty (mk_default fail ++ alts))
mk_alt fail (con, args, MatchResult _ body_fn)
-- Stuff for parallel arrays
--
- -- * the following is to desugar cases over fake constructors for
+ -- * the following is to desugar cases over fake constructors for
-- parallel arrays, which are introduced by `tidy1' in the `PArrPat'
-- case
--
-- Concerning `isPArrFakeAlts':
--
- -- * it is *not* sufficient to just check the type of the type
+ -- * it is *not* sufficient to just check the type of the type
-- constructor, as we have to be careful not to confuse the real
-- representation of parallel arrays with the fake constructors;
-- moreover, a list of alternatives must not mix fake and real
--
unboxAlt =
newSysLocalDs intPrimTy `thenDs` \l ->
- dsLookupGlobalId indexPName `thenDs` \indexP ->
- mappM (mkAlt indexP) match_alts `thenDs` \alts ->
+ dsLookupGlobalId indexPName `thenDs` \indexP ->
+ mappM (mkAlt indexP) sorted_alts `thenDs` \alts ->
returnDs (DataAlt intDataCon, [l], (Case (Var l) wild ty (dft : alts)))
where
wild = mkWildId intPrimTy
let
full_msg = showSDoc (hcat [ppr src_loc, text "|", text msg])
core_msg = Lit (mkStringLit full_msg)
+ -- mkStringLit returns a result of type String#
in
returnDs (mkApps (Var err_id) [Type ty, core_msg])
\end{code}
mkStringExpr str = mkStringExprFS (mkFastString str)
mkStringExprFS str
- | nullFastString str
+ | nullFS str
= returnDs (mkNilExpr charTy)
| lengthFS str == 1
in
returnDs (mkConsExpr charTy the_char (mkNilExpr charTy))
- | all safeChar int_chars
+ | all safeChar chars
= dsLookupGlobalId unpackCStringName `thenDs` \ unpack_id ->
returnDs (App (Var unpack_id) (Lit (MachStr str)))
| otherwise
= dsLookupGlobalId unpackCStringUtf8Name `thenDs` \ unpack_id ->
- returnDs (App (Var unpack_id) (Lit (MachStr (mkFastString (intsToUtf8 int_chars)))))
+ returnDs (App (Var unpack_id) (Lit (MachStr str)))
where
- int_chars = unpackIntFS str
- safeChar c = c >= 1 && c <= 0xFF
+ chars = unpackFS str
+ safeChar c = ord c >= 1 && ord c <= 0x7F
\end{code}
mkSmallTupleCase [var] body _scrut_var scrut
= bindNonRec var scrut body
mkSmallTupleCase vars body scrut_var scrut
--- gaw 2004
-- One branch no refinement?
= Case scrut scrut_var (exprType body) [(DataAlt (tupleCon Boxed (length vars)), vars, body)]
\end{code}
mkCoreSel vars the_var scrut_var scrut
= ASSERT( notNull vars )
--- gaw 2004
Case scrut scrut_var (idType the_var)
[(DataAlt (tupleCon Boxed (length vars)), vars, Var the_var)]
\end{code}
projects / ghc-hetmet.git / blobdiff