import HsLoop ( HsExpr )
-- others:
-import Id ( GenId, getDataConSig )
+import Id ( GenId, dataConSig )
import Maybes ( maybeToBool )
-import Outputable
+import Name ( pprSym, pprNonSym )
+import Outputable ( interppSP, interpp'SP, ifPprShowAll )
import PprStyle ( PprStyle(..) )
import Pretty
import TyCon ( maybeTyConSingleCon )
-import TyVar ( GenTyVar )
-import PprType ( GenType, GenTyVar )
-import Unique ( Unique )
-
+import PprType ( GenType )
\end{code}
Patterns come in distinct before- and after-typechecking flavo(u)rs.
| ConOpPatIn (InPat name)
name
(InPat name)
+
+ -- We preserve prefix negation and parenthesis for the precedence parser.
+
+ | NegPatIn (InPat name) -- negated pattern
+ | ParPatIn (InPat name) -- parenthesised pattern
+
| ListPatIn [InPat name] -- syntactic list
-- must have >= 1 elements
| TuplePatIn [InPat name] -- tuple
| RecPatIn name -- record
- [(name, Maybe (InPat name))]
+ [(name, InPat name, Bool)] -- True <=> source used punning
data OutPat tyvar uvar id
- = WildPat (GenType tyvar uvar) -- wild card
+ = WildPat (GenType tyvar uvar) -- wild card
| VarPat id -- variable (type is in the Id)
| ConPat Id -- Constructor is always an Id
(GenType tyvar uvar) -- the type of the pattern
- [(OutPat tyvar uvar id)]
+ [OutPat tyvar uvar id]
| ConOpPat (OutPat tyvar uvar id) -- just a special case...
Id
(GenType tyvar uvar)
| ListPat -- syntactic list
(GenType tyvar uvar) -- the type of the elements
- [(OutPat tyvar uvar id)]
+ [OutPat tyvar uvar id]
- | TuplePat [(OutPat tyvar uvar id)] -- tuple
+ | TuplePat [OutPat tyvar uvar id] -- tuple
-- UnitPat is TuplePat []
- | RecPat id -- record
- [(id, Maybe (OutPat tyvar uvar id))]
+ | RecPat Id -- record constructor
+ (GenType tyvar uvar) -- the type of the pattern
+ [(Id, OutPat tyvar uvar id, Bool)] -- True <=> source used punning
| LitPat -- Used for *non-overloaded* literal patterns:
-- Int#, Char#, Int, Char, String, etc.
(HsExpr tyvar uvar id (OutPat tyvar uvar id))
-- of type t -> Bool; detects match
- | DictPat -- Used when destructing Dictionaries with an explicit case
+ | DictPat -- Used when destructing Dictionaries with an explicit case
[id] -- superclass dicts
[id] -- methods
\end{code}
pprInPat :: (Outputable name, NamedThing name) => PprStyle -> InPat name -> Pretty
pprInPat sty (WildPatIn) = ppStr "_"
-pprInPat sty (VarPatIn var) = pprNonOp sty var
+pprInPat sty (VarPatIn var) = pprNonSym sty var
pprInPat sty (LitPatIn s) = ppr sty s
pprInPat sty (LazyPatIn pat) = ppBeside (ppChar '~') (ppr sty pat)
pprInPat sty (AsPatIn name pat)
= if null pats then
ppr sty c
else
- ppBesides [ppLparen, ppr sty c, ppSP, interppSP sty pats, ppRparen]
-
+ ppCat [ppr sty c, interppSP sty pats] -- ParPats put in the parens
pprInPat sty (ConOpPatIn pat1 op pat2)
- = ppBesides [ppLparen, ppr sty pat1, ppSP, ppr sty op, ppSP, ppr sty pat2, ppRparen]
+ = ppCat [ppr sty pat1, ppr sty op, ppr sty pat2] -- ParPats put in parens
+
+ -- ToDo: use pprSym to print op (but this involves fiddling various
+ -- contexts & I'm lazy...); *PatIns are *rarely* printed anyway... (WDP)
+
+pprInPat sty (NegPatIn pat)
+ = let
+ pp_pat = pprInPat sty pat
+ in
+ ppBeside (ppChar '-') (
+ case pat of
+ LitPatIn _ -> pp_pat
+ _ -> ppParens pp_pat
+ )
--- ToDo: use pprOp to print op (but this involves fiddling various
--- contexts & I'm lazy...); *PatIns are *rarely* printed anyway... (WDP)
+pprInPat sty (ParPatIn pat)
+ = ppParens (pprInPat sty pat)
pprInPat sty (ListPatIn pats)
= ppBesides [ppLbrack, interpp'SP sty pats, ppRbrack]
pprInPat sty (TuplePatIn pats)
- = ppBesides [ppLparen, interpp'SP sty pats, ppRparen]
+ = ppParens (interpp'SP sty pats)
pprInPat sty (RecPatIn con rpats)
- = ppBesides [ppr sty con, ppSP, ppChar '{', ppInterleave ppComma (map pp_rpat rpats), ppChar '}']
+ = ppBesides [ppr sty con, ppSP, ppChar '{', ppInterleave ppComma (map (pp_rpat sty) rpats), ppChar '}']
where
- pp_rpat (v, Nothing) = ppr sty v
- pp_rpat (v, Just p) = ppCat [ppr sty v, ppStr "<-", ppr sty p]
+ pp_rpat PprForUser (v, _, True) = ppr PprForUser v
+ pp_rpat sty (v, p, _) = ppCat [ppr sty v, ppStr "=", ppr sty p]
\end{code}
\begin{code}
\begin{code}
pprOutPat sty (WildPat ty) = ppChar '_'
-pprOutPat sty (VarPat var) = pprNonOp sty var
+pprOutPat sty (VarPat var) = pprNonSym sty var
pprOutPat sty (LazyPat pat) = ppBesides [ppChar '~', ppr sty pat]
pprOutPat sty (AsPat name pat)
= ppBesides [ppLparen, ppr sty name, ppChar '@', ppr sty pat, ppRparen]
ifPprShowAll sty (pprConPatTy sty ty) ]
pprOutPat sty (ConOpPat pat1 op pat2 ty)
- = ppBesides [ppLparen, ppr sty pat1, ppSP, pprOp sty op, ppSP, ppr sty pat2, ppRparen]
+ = ppBesides [ppLparen, ppr sty pat1, ppSP, pprSym sty op, ppSP, ppr sty pat2, ppRparen]
pprOutPat sty (ListPat ty pats)
= ppBesides [ppLbrack, interpp'SP sty pats, ppRbrack]
pprOutPat sty (TuplePat pats)
- = ppBesides [ppLparen, interpp'SP sty pats, ppRparen]
+ = ppParens (interpp'SP sty pats)
-pprOutPat sty (RecPat con rpats)
- = ppBesides [ppr sty con, ppChar '{', ppInterleave ppComma (map pp_rpat rpats), ppChar '}']
+pprOutPat sty (RecPat con ty rpats)
+ = ppBesides [ppr sty con, ppChar '{', ppInterleave ppComma (map (pp_rpat sty) rpats), ppChar '}']
where
- pp_rpat (v, Nothing) = ppr sty v
- pp_rpat (v, Just p) = ppBesides [ppr sty v, ppStr "<-", ppr sty p]
+ pp_rpat PprForUser (v, _, True) = ppr PprForUser v
+ pp_rpat sty (v, p, _) = ppCat [ppr sty v, ppStr "=", ppr sty p]
pprOutPat sty (LitPat l ty) = ppr sty l -- ToDo: print more
pprOutPat sty (NPat l ty e) = ppr sty l -- ToDo: print more
ppBesides [ppBracket (interpp'SP sty methods), ppRparen]]
pprConPatTy sty ty
- = ppBesides [ppLparen, ppr sty ty, ppRparen]
+ = ppParens (ppr sty ty)
\end{code}
%************************************************************************
isConPat (ConOpPat _ _ _ _) = True
isConPat (ListPat _ _) = True
isConPat (TuplePat _) = True
+isConPat (RecPat _ _ _) = True
isConPat (DictPat ds ms) = (length ds + length ms) > 1
isConPat other = False
irrefutablePat (VarPat _) = True
irrefutablePat (LazyPat _) = True
irrefutablePat (AsPat _ pat) = irrefutablePat pat
-irrefutablePat (ConPat con tys pats) = all irrefutablePat pats && only_con con
-irrefutablePat (ConOpPat pat1 con pat2 _) = irrefutablePat pat1 && irrefutablePat pat1 && only_con con
+irrefutablePat (ConPat con tys pats) = only_con con && all irrefutablePat pats
+irrefutablePat (ConOpPat pat1 con pat2 _) = only_con con && irrefutablePat pat1 && irrefutablePat pat1
+irrefutablePat (RecPat con _ fields) = only_con con && and [ irrefutablePat pat | (_,pat,_) <- fields ]
irrefutablePat (ListPat _ _) = False
irrefutablePat (TuplePat pats) = all irrefutablePat pats
irrefutablePat (DictPat _ _) = True
only_con con = maybeToBool (maybeTyConSingleCon tycon)
where
- (_,_,_,tycon) = getDataConSig con
+ (_,_,_,tycon) = dataConSig con
\end{code}
This function @collectPatBinders@ works with the ``collectBinders''
\begin{code}
collectPatBinders :: InPat a -> [a]
-collectPatBinders (VarPatIn var) = [var]
-collectPatBinders (LazyPatIn pat) = collectPatBinders pat
-collectPatBinders (AsPatIn a pat) = a : collectPatBinders pat
-collectPatBinders (ConPatIn c pats) = concat (map collectPatBinders pats)
+collectPatBinders WildPatIn = []
+collectPatBinders (VarPatIn var) = [var]
+collectPatBinders (LitPatIn _) = []
+collectPatBinders (LazyPatIn pat) = collectPatBinders pat
+collectPatBinders (AsPatIn a pat) = a : collectPatBinders pat
+collectPatBinders (ConPatIn c pats) = concat (map collectPatBinders pats)
collectPatBinders (ConOpPatIn p1 c p2)= collectPatBinders p1 ++ collectPatBinders p2
-collectPatBinders (ListPatIn pats) = concat (map collectPatBinders pats)
-collectPatBinders (TuplePatIn pats) = concat (map collectPatBinders pats)
-collectPatBinders any_other_pat = [ {-no binders-} ]
+collectPatBinders (NegPatIn pat) = collectPatBinders pat
+collectPatBinders (ParPatIn pat) = collectPatBinders pat
+collectPatBinders (ListPatIn pats) = concat (map collectPatBinders pats)
+collectPatBinders (TuplePatIn pats) = concat (map collectPatBinders pats)
+collectPatBinders (RecPatIn c fields) = concat (map (\ (f,pat,_) -> collectPatBinders pat) fields)
\end{code}
projects / ghc-hetmet.git / blobdiff