%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[PatSyntax]{Abstract Haskell syntax---patterns}
\begin{code}
-#include "HsVersions.h"
-
module HsPat (
InPat(..),
OutPat(..),
collectPatBinders
) where
-IMP_Ubiq()
+#include "HsVersions.h"
-- friends:
-import HsBasic ( HsLit, Fixity )
-IMPORT_DELOOPER(HsLoop) ( HsExpr )
+import HsBasic ( HsLit )
+import HsExpr ( HsExpr )
+import BasicTypes ( Fixity )
-- others:
-import Id ( dataConTyCon, GenId )
+import Var ( Id, GenTyVar )
+import DataCon ( DataCon, dataConTyCon )
import Maybes ( maybeToBool )
-import Name ( pprSym, pprNonSym )
-import Outputable ( interppSP, interpp'SP, ifPprShowAll )
-import PprStyle ( PprStyle(..) )
-import Pretty
+import Outputable
import TyCon ( maybeTyConSingleCon )
-import PprType ( GenType )
+import Type ( GenType )
\end{code}
Patterns come in distinct before- and after-typechecking flavo(u)rs.
| ListPatIn [InPat name] -- syntactic list
-- must have >= 1 elements
- | TuplePatIn [InPat name] -- tuple
+ | TuplePatIn [InPat name] Bool -- tuple (boxed?)
| RecPatIn name -- record
[(name, InPat name, Bool)] -- True <=> source used punning
-data OutPat tyvar uvar id
- = WildPat (GenType tyvar uvar) -- wild card
+data OutPat flexi id
+ = WildPat (GenType flexi) -- wild card
| VarPat id -- variable (type is in the Id)
- | LazyPat (OutPat tyvar uvar id) -- lazy pattern
+ | LazyPat (OutPat flexi id) -- lazy pattern
| AsPat id -- as pattern
- (OutPat tyvar uvar id)
-
- | ConPat Id -- Constructor is always an Id
- (GenType tyvar uvar) -- the type of the pattern
- [OutPat tyvar uvar id]
+ (OutPat flexi id)
- | ConOpPat (OutPat tyvar uvar id) -- just a special case...
- Id
- (OutPat tyvar uvar id)
- (GenType tyvar uvar)
| ListPat -- syntactic list
- (GenType tyvar uvar) -- the type of the elements
- [OutPat tyvar uvar id]
+ (GenType flexi) -- the type of the elements
+ [OutPat flexi id]
- | TuplePat [OutPat tyvar uvar id] -- tuple
+ | TuplePat [OutPat flexi id] -- tuple
+ Bool -- boxed?
-- UnitPat is TuplePat []
- | RecPat Id -- record constructor
- (GenType tyvar uvar) -- the type of the pattern
- [(Id, OutPat tyvar uvar id, Bool)] -- True <=> source used punning
+ | ConPat DataCon
+ (GenType flexi) -- the type of the pattern
+ [GenTyVar flexi] -- Existentially bound type variables
+ [id] -- Ditto dictionaries
+ [OutPat flexi id]
+
+ -- ConOpPats are only used on the input side
+
+ | RecPat DataCon -- record constructor
+ (GenType flexi) -- the type of the pattern
+ [GenTyVar flexi] -- Existentially bound type variables
+ [id] -- Ditto dictionaries
+ [(Id, OutPat flexi id, Bool)] -- True <=> source used punning
| LitPat -- Used for *non-overloaded* literal patterns:
-- Int#, Char#, Int, Char, String, etc.
HsLit
- (GenType tyvar uvar) -- type of pattern
+ (GenType flexi) -- type of pattern
| NPat -- Used for *overloaded* literal patterns
HsLit -- the literal is retained so that
-- the desugarer can readily identify
-- equations with identical literal-patterns
- (GenType tyvar uvar) -- type of pattern, t
- (HsExpr tyvar uvar id (OutPat tyvar uvar id))
+ (GenType flexi) -- type of pattern, t
+ (HsExpr flexi id (OutPat flexi id))
-- of type t -> Bool; detects match
| NPlusKPat id
-- (This could be an Integer, but then
-- it's harder to partitionEqnsByLit
-- in the desugarer.)
- (GenType tyvar uvar) -- Type of pattern, t
- (HsExpr tyvar uvar id (OutPat tyvar uvar id)) -- Of type t -> Bool; detects match
- (HsExpr tyvar uvar id (OutPat tyvar uvar id)) -- Of type t -> t; subtracts k
+ (GenType flexi) -- Type of pattern, t
+ (HsExpr flexi id (OutPat flexi id)) -- Of type t -> Bool; detects match
+ (HsExpr flexi id (OutPat flexi id)) -- Of type t -> t; subtracts k
| DictPat -- Used when destructing Dictionaries with an explicit case
[id] -- superclass dicts
[id] -- methods
\end{code}
+Now name in Inpat is not need to be in NAmedThing to be Outputable.
+Needed by ../deSugar/Check.lhs
+
+JJQC-2-12-97
+
\begin{code}
-instance (Outputable name, NamedThing name) => Outputable (InPat name) where
+instance (Outputable name) => Outputable (InPat name) where
ppr = pprInPat
-pprInPat :: (Outputable name, NamedThing name) => PprStyle -> InPat name -> Pretty
+pprInPat :: (Outputable name) => InPat name -> SDoc
-pprInPat sty (WildPatIn) = ppChar '_'
-pprInPat sty (VarPatIn var) = ppr sty var
-pprInPat sty (LitPatIn s) = ppr sty s
-pprInPat sty (LazyPatIn pat) = ppBeside (ppChar '~') (ppr sty pat)
-pprInPat sty (AsPatIn name pat)
- = ppBesides [ppLparen, ppr sty name, ppChar '@', ppr sty pat, ppRparen]
+pprInPat (WildPatIn) = char '_'
+pprInPat (VarPatIn var) = ppr var
+pprInPat (LitPatIn s) = ppr s
+pprInPat (LazyPatIn pat) = char '~' <> ppr pat
+pprInPat (AsPatIn name pat) = parens (hcat [ppr name, char '@', ppr pat])
-pprInPat sty (ConPatIn c pats)
- = if null pats then
- ppr sty c
- else
- ppCat [ppr sty c, interppSP sty pats] -- ParPats put in the parens
+pprInPat (ConPatIn c pats)
+ | null pats = ppr c
+ | otherwise = hsep [ppr c, interppSP pats] -- ParPats put in the parens
-pprInPat sty (ConOpPatIn pat1 op fixity pat2)
- = ppCat [ppr sty pat1, ppr sty op, ppr sty pat2] -- ParPats put in parens
+pprInPat (ConOpPatIn pat1 op fixity pat2)
+ = hsep [ppr pat1, ppr op, ppr 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)
+pprInPat (NegPatIn pat)
= let
- pp_pat = pprInPat sty pat
+ pp_pat = pprInPat pat
in
- ppBeside (ppChar '-') (
+ char '-' <> (
case pat of
LitPatIn _ -> pp_pat
- _ -> ppParens pp_pat
+ _ -> parens pp_pat
)
-pprInPat sty (ParPatIn pat)
- = ppParens (pprInPat sty pat)
+pprInPat (ParPatIn pat)
+ = parens (pprInPat pat)
-pprInPat sty (ListPatIn pats)
- = ppBesides [ppLbrack, interpp'SP sty pats, ppRbrack]
-pprInPat sty (TuplePatIn pats)
- = ppParens (interpp'SP sty pats)
-pprInPat sty (NPlusKPatIn n k)
- = ppBesides [ppLparen, ppr sty n, ppChar '+', ppr sty k, ppRparen]
+pprInPat (ListPatIn pats)
+ = brackets (interpp'SP pats)
+pprInPat (TuplePatIn pats False)
+ = text "(#" <> (interpp'SP pats) <> text "#)"
+pprInPat (TuplePatIn pats True)
+ = parens (interpp'SP pats)
+pprInPat (NPlusKPatIn n k)
+ = parens (hcat [ppr n, char '+', ppr k])
-pprInPat sty (RecPatIn con rpats)
- = ppCat [ppr sty con, ppCurlies (ppIntersperse pp'SP (map (pp_rpat sty) rpats))]
+pprInPat (RecPatIn con rpats)
+ = hsep [ppr con, braces (hsep (punctuate comma (map (pp_rpat) rpats)))]
where
- pp_rpat PprForUser (v, _, True) = ppr PprForUser v
- pp_rpat sty (v, p, _) = ppCat [ppr sty v, ppChar '=', ppr sty p]
+ pp_rpat (v, _, True) = ppr v
+ pp_rpat (v, p, _) = hsep [ppr v, char '=', ppr p]
\end{code}
\begin{code}
-instance (Eq tyvar, Outputable tyvar, Eq uvar, Outputable uvar, Outputable id)
- => Outputable (OutPat tyvar uvar id) where
+instance (Outputable id) => Outputable (OutPat flexi id) where
ppr = pprOutPat
\end{code}
\begin{code}
-pprOutPat sty (WildPat ty) = ppChar '_'
-pprOutPat sty (VarPat var) = ppr 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]
-
-pprOutPat sty (ConPat name ty [])
- = ppBeside (ppr sty name)
- (ifPprShowAll sty (pprConPatTy sty ty))
-
-pprOutPat sty (ConPat name ty pats)
- = ppBesides [ppLparen, ppr sty name, ppSP,
- interppSP sty pats, ppRparen,
- ifPprShowAll sty (pprConPatTy sty ty) ]
-
-pprOutPat sty (ConOpPat pat1 op pat2 ty)
- = 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)
- = ppParens (interpp'SP sty pats)
-
-pprOutPat sty (RecPat con ty rpats)
- = ppBesides [ppr sty con, ppCurlies (ppIntersperse pp'SP (map (pp_rpat sty) rpats))]
+pprOutPat (WildPat ty) = char '_'
+pprOutPat (VarPat var) = ppr var
+pprOutPat (LazyPat pat) = hcat [char '~', ppr pat]
+pprOutPat (AsPat name pat)
+ = parens (hcat [ppr name, char '@', ppr pat])
+
+pprOutPat (ConPat name ty [] [] [])
+ = ppr name
+
+pprOutPat (ConPat name ty tyvars dicts pats)
+ = parens (hsep [ppr name, interppSP tyvars, interppSP dicts, interppSP pats])
+
+pprOutPat (ListPat ty pats)
+ = brackets (interpp'SP pats)
+pprOutPat (TuplePat pats boxed@True)
+ = parens (interpp'SP pats)
+pprOutPat (TuplePat pats unboxed@False)
+ = text "(#" <> (interpp'SP pats) <> text "#)"
+
+pprOutPat (RecPat con ty tvs dicts rpats)
+ = hsep [ppr con, interppSP tvs, interppSP dicts, braces (hsep (punctuate comma (map (pp_rpat) rpats)))]
where
- pp_rpat PprForUser (v, _, True) = ppr PprForUser v
- pp_rpat sty (v, p, _) = ppCat [ppr sty v, ppChar '=', ppr sty p]
+ pp_rpat (v, _, True) = ppr v
+ pp_rpat (v, p, _) = hsep [ppr v, char '=', ppr p]
-pprOutPat sty (LitPat l ty) = ppr sty l -- ToDo: print more
-pprOutPat sty (NPat l ty e) = ppr sty l -- ToDo: print more
-pprOutPat sty (NPlusKPat n k ty e1 e2) -- ToDo: print more
- = ppBesides [ppLparen, ppr sty n, ppChar '+', ppr sty k, ppRparen]
+pprOutPat (LitPat l ty) = ppr l -- ToDo: print more
+pprOutPat (NPat l ty e) = ppr l -- ToDo: print more
+pprOutPat (NPlusKPat n k ty e1 e2) -- ToDo: print more
+ = parens (hcat [ppr n, char '+', ppr k])
-pprOutPat sty (DictPat dicts methods)
- = ppSep [ppBesides [ppLparen, ppPStr SLIT("{-dict-}")],
- ppBracket (interpp'SP sty dicts),
- ppBesides [ppBracket (interpp'SP sty methods), ppRparen]]
+pprOutPat (DictPat dicts methods)
+ = parens (sep [ptext SLIT("{-dict-}"),
+ brackets (interpp'SP dicts),
+ brackets (interpp'SP methods)])
-pprConPatTy sty ty
- = ppParens (ppr sty ty)
\end{code}
%************************************************************************
The 1.3 report defines what ``irrefutable'' and ``failure-free'' patterns are.
\begin{code}
-irrefutablePats :: [OutPat a b c] -> Bool
+irrefutablePats :: [OutPat a b] -> Bool
irrefutablePats pat_list = all irrefutablePat pat_list
irrefutablePat (AsPat _ pat) = irrefutablePat pat
irrefutablePat (DictPat ds ms) = (length ds + length ms) <= 1
irrefutablePat other = False
-failureFreePat :: OutPat a b c -> Bool
+failureFreePat :: OutPat a b -> Bool
failureFreePat (WildPat _) = True
failureFreePat (VarPat _) = True
failureFreePat (LazyPat _) = True
failureFreePat (AsPat _ pat) = failureFreePat pat
-failureFreePat (ConPat con tys pats) = only_con con && all failureFreePat pats
-failureFreePat (ConOpPat pat1 con pat2 _) = only_con con && failureFreePat pat1 && failureFreePat pat1
-failureFreePat (RecPat con _ fields) = only_con con && and [ failureFreePat pat | (_,pat,_) <- fields ]
+failureFreePat (ConPat con tys _ _ pats) = only_con con && all failureFreePat pats
+failureFreePat (RecPat con _ _ _ fields) = only_con con && and [ failureFreePat pat | (_,pat,_) <- fields ]
failureFreePat (ListPat _ _) = False
-failureFreePat (TuplePat pats) = all failureFreePat pats
+failureFreePat (TuplePat pats _) = all failureFreePat pats
failureFreePat (DictPat _ _) = True
failureFreePat other_pat = False -- Literals, NPat
\end{code}
\begin{code}
-patsAreAllCons :: [OutPat a b c] -> Bool
+patsAreAllCons :: [OutPat a b] -> Bool
patsAreAllCons pat_list = all isConPat pat_list
isConPat (AsPat _ pat) = isConPat pat
-isConPat (ConPat _ _ _) = True
-isConPat (ConOpPat _ _ _ _) = True
+isConPat (ConPat _ _ _ _ _) = True
isConPat (ListPat _ _) = True
-isConPat (TuplePat _) = True
-isConPat (RecPat _ _ _) = True
+isConPat (TuplePat _ _) = True
+isConPat (RecPat _ _ _ _ _) = True
isConPat (DictPat ds ms) = (length ds + length ms) > 1
isConPat other = False
-patsAreAllLits :: [OutPat a b c] -> Bool
+patsAreAllLits :: [OutPat a b] -> Bool
patsAreAllLits pat_list = all isLitPat pat_list
isLitPat (AsPat _ pat) = isLitPat pat
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 (TuplePatIn pats _) = concat (map collectPatBinders pats)
collectPatBinders (RecPatIn c fields) = concat (map (\ (f,pat,_) -> collectPatBinders pat) fields)
\end{code}
projects / ghc-hetmet.git / blobdiff