%
-% (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
+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 Ubiq
+import DsLoop -- break match-ish and dsExpr-ish loops
-import AbsUniType ( isPrimType, getUniDataTyCon, kindFromType )
-import BasicLit ( mkMachInt, BasicLit(..), PrimKind )
-import DsExpr ( dsExpr )
+import HsSyn ( HsLit(..), OutPat(..), HsExpr(..),
+ Match, HsBinds, Stmt, Qual, PolyType, ArithSeqInfo )
+import TcHsSyn ( TypecheckedHsExpr(..) )
+import CoreSyn ( CoreExpr(..) )
+
+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 )
+import Util ( panic, assertPanic )
\end{code}
\begin{code}
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
+ = partitionEqnsByLit literal eqns_info
(shifted_shadows_for_this_lit, shadows_not_for_this_lit)
- = partitionEqnsByLit Nothing literal shadows
+ = partitionEqnsByLit literal shadows
in
-- recursive call to make other alts...
match_prims_used vars eqns_not_for_this_lit shadows_not_for_this_lit `thenDs` \ rest_of_alts ->
-- 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; primRepFromType???")
+ mk_core_lit ty other = panic "matchLiterals:mk_core_lit:unhandled"
\end{code}
\begin{code}
matchLiterals all_vars@(var:vars) eqns_info@(EqnInfo ((NPat literal lit_ty eq_chk):ps1) _ : eqns) shadows
= let
(shifted_eqns_for_this_lit, eqns_not_for_this_lit)
- = partitionEqnsByLit Nothing literal eqns_info
+ = partitionEqnsByLit literal eqns_info
(shifted_shadows_for_this_lit, shadows_not_for_this_lit)
- = partitionEqnsByLit Nothing literal shadows
+ = partitionEqnsByLit 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}
<try-next-pattern-or-whatever>
\end{verbatim}
-\begin{code}
-matchLiterals all_vars@(var:vars) eqns_info@(EqnInfo ((NPlusKPat master_n k ty from_lit ge sub):ps1) _ : eqns) shadows
- = let
- (shifted_eqns_for_this_lit, eqns_not_for_this_lit)
- = partitionEqnsByLit (Just master_n) k eqns_info
- (shifted_shadows_for_this_lit, shadows_not_for_this_lit)
- = partitionEqnsByLit (Just master_n) k shadows
- 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 ->
-
- mkGuardedMatchResult
- var_ge_lit
- (mkCoLetsMatchResult [CoNonRec master_n var_sub_lit] inner_match_result)
- `thenDs` \ match_result1 ->
-
- if (null eqns_not_for_this_lit)
- then
- returnDs match_result1
- else
- matchLiterals all_vars eqns_not_for_this_lit shadows_not_for_this_lit `thenDs` \ match_result2 ->
- 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
- -- is the "master" variable;
- -- Nothing for NPats and LitPats
- -> Literal
+partitionEqnsByLit :: HsLit
-> [EquationInfo]
-> ([EquationInfo], -- These ones are for this lit, AND
-- they've been "shifted" by stripping
-- are exactly as fed in.
)
-partitionEqnsByLit want_NPlusK lit eqns
+partitionEqnsByLit lit eqns
= ( \ (xs,ys) -> (catMaybes xs, catMaybes ys))
- (unzip (map (partition_eqn want_NPlusK lit) eqns))
+ (unzip (map (partition_eqn lit) eqns))
where
- partition_eqn :: Maybe Id -> Literal -> EquationInfo ->
+ partition_eqn :: HsLit -> EquationInfo ->
(Maybe EquationInfo, Maybe EquationInfo)
- partition_eqn Nothing lit (EqnInfo (LitPat k _ : remaining_pats) match_result)
+ partition_eqn 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
- partition_eqn Nothing lit (EqnInfo (NPat k _ _ : remaining_pats) match_result)
+ partition_eqn 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
- 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
- where
- new_match_result = if master_n `eqId` n then
- match_result
- else
- mkCoLetsMatchResult [CoNonRec n (CoVar 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 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 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}
projects / ghc-hetmet.git / blobdiff