OutPat(..),
irrefutablePat, irrefutablePats,
- failureFreePat, isWildPat,
- patsAreAllCons, isConPat,
+ failureFreePat, isWildPat,
+ patsAreAllCons, isConPat,
patsAreAllLits, isLitPat,
- collectPatBinders, collectPatsBinders
+ collectPatBinders, collectOutPatBinders, collectPatsBinders,
+ collectSigTysFromPat, collectSigTysFromPats
) where
#include "HsVersions.h"
+
-- friends:
-import HsBasic ( HsLit )
+import HsLit ( HsLit, HsOverLit )
import HsExpr ( HsExpr )
import HsTypes ( HsType )
import BasicTypes ( Fixity, Boxity, tupleParens )
-- others:
+import Name ( Name )
import Var ( Id, TyVar )
import DataCon ( DataCon, dataConTyCon )
import Name ( isDataSymOcc, getOccName, NamedThing )
Fixity -- c.f. OpApp in HsExpr
(InPat name)
- | NPlusKPatIn name -- n+k pattern
- HsLit
+ | NPatIn HsOverLit -- Always positive
+ (Maybe Name) -- Just (Name of 'negate') for negative
+ -- patterns, Nothing otherwise
+ -- (see RnEnv.lookupSyntaxName)
+
+ | NPlusKPatIn name -- n+k pattern
+ HsOverLit -- It'll always be an HsIntegral
+ Name -- Name of '-' (see RnEnv.lookupSyntaxName)
-- 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
+ | PArrPatIn [InPat name] -- syntactic parallel array
+ -- must have >= 1 elements
| TuplePatIn [InPat name] Boxity -- tuple (boxed?)
| RecPatIn name -- record
[(name, InPat name, Bool)] -- True <=> source used punning
+-- Generics
+ | TypePatIn (HsType name) -- Type pattern for generic definitions
+ -- e.g f{| a+b |} = ...
+ -- These show up only in class
+ -- declarations,
+ -- and should be a top-level pattern
+
+-- /Generics
+
data OutPat id
= WildPat Type -- wild card
| VarPat id -- variable (type is in the Id)
| AsPat id -- as pattern
(OutPat id)
- | ListPat -- syntactic list
- Type -- the type of the elements
+ | SigPat (OutPat id) -- Pattern p
+ Type -- Type, t, of the whole pattern
+ (HsExpr id (OutPat id))
+ -- Coercion function,
+ -- of type t -> typeof(p)
+
+ | ListPat -- Syntactic list
+ Type -- The type of the elements
+ [OutPat id]
+ | PArrPat -- Syntactic parallel array
+ Type -- The type of the elements
[OutPat id]
- | TuplePat [OutPat id] -- tuple
+ | TuplePat [OutPat id] -- Tuple
Boxity
- -- UnitPat is TuplePat []
+ -- UnitPat is TuplePat []
| ConPat DataCon
Type -- the type of the pattern
-- ConOpPats are only used on the input side
- | RecPat DataCon -- record constructor
- Type -- the type of the pattern
- [TyVar] -- Existentially bound type variables
+ | RecPat DataCon -- Record constructor
+ Type -- The type of the pattern
+ [TyVar] -- Existentially bound type variables
[id] -- Ditto dictionaries
[(Id, OutPat id, Bool)] -- True <=> source used punning
| LitPat -- Used for *non-overloaded* literal patterns:
-- Int#, Char#, Int, Char, String, etc.
HsLit
- Type -- type of pattern
+ Type -- Type of pattern
- | NPat -- Used for *overloaded* literal patterns
- HsLit -- the literal is retained so that
+ | NPat -- Used for literal patterns where there's an equality function to call
+ HsLit -- The literal is retained so that
-- the desugarer can readily identify
-- equations with identical literal-patterns
- Type -- type of pattern, t
- (HsExpr id (OutPat id))
- -- of type t -> Bool; detects match
+ -- Always HsInteger, HsRat or HsString.
+ Type -- Type of pattern, t
+ (HsExpr id (OutPat id)) -- Of type t -> Bool; detects match
| NPlusKPat id
- HsLit -- Same reason as for LitPat
- -- (This could be an Integer, but then
- -- it's harder to partitionEqnsByLit
- -- in the desugarer.)
- Type -- Type of pattern, t
+ Integer
+ Type -- Type of pattern, t
(HsExpr id (OutPat id)) -- Of type t -> Bool; detects match
(HsExpr id (OutPat id)) -- Of type t -> t; subtracts k
pprInPat :: (Outputable name) => InPat name -> SDoc
-pprInPat (WildPatIn) = char '_'
-pprInPat (VarPatIn var) = ppr var
-pprInPat (LitPatIn s) = ppr s
-pprInPat (SigPatIn pat ty) = ppr pat <+> dcolon <+> ppr ty
-pprInPat (LazyPatIn pat) = char '~' <> ppr pat
-pprInPat (AsPatIn name pat) = parens (hcat [ppr name, char '@', ppr pat])
+pprInPat (WildPatIn) = char '_'
+pprInPat (VarPatIn var) = ppr var
+pprInPat (LitPatIn s) = ppr s
+pprInPat (SigPatIn pat ty) = ppr pat <+> dcolon <+> ppr ty
+pprInPat (LazyPatIn pat) = char '~' <> ppr pat
+pprInPat (AsPatIn name pat) = parens (hcat [ppr name, char '@', ppr pat])
+pprInPat (ParPatIn pat) = parens (pprInPat pat)
+pprInPat (ListPatIn pats) = brackets (interpp'SP pats)
+pprInPat (PArrPatIn pats) = pabrackets (interpp'SP pats)
+pprInPat (TuplePatIn pats bx) = tupleParens bx (interpp'SP pats)
+pprInPat (NPlusKPatIn n k _) = parens (hcat [ppr n, char '+', ppr k])
+pprInPat (NPatIn l _) = ppr l
pprInPat (ConPatIn c pats)
| null pats = ppr c
-- ToDo: use pprSym to print op (but this involves fiddling various
-- contexts & I'm lazy...); *PatIns are *rarely* printed anyway... (WDP)
-pprInPat (NegPatIn pat)
- = let
- pp_pat = pprInPat pat
- in
- char '-' <> (
- case pat of
- LitPatIn _ -> pp_pat
- _ -> parens pp_pat
- )
-
-pprInPat (ParPatIn pat)
- = parens (pprInPat pat)
-
-pprInPat (ListPatIn pats)
- = brackets (interpp'SP pats)
-pprInPat (TuplePatIn pats boxity)
- = tupleParens boxity (interpp'SP pats)
-pprInPat (NPlusKPatIn n k)
- = parens (hcat [ppr n, char '+', ppr k])
-
pprInPat (RecPatIn con rpats)
= hsep [ppr con, braces (hsep (punctuate comma (map (pp_rpat) rpats)))]
where
pp_rpat (v, _, True) = ppr v
pp_rpat (v, p, _) = hsep [ppr v, char '=', ppr p]
+
+pprInPat (TypePatIn ty) = ptext SLIT("{|") <> ppr ty <> ptext SLIT("|}")
+
+-- add parallel array brackets around a document
+--
+pabrackets :: SDoc -> SDoc
+pabrackets p = ptext SLIT("[:") <> p <> ptext SLIT(":]")
\end{code}
\begin{code}
pprOutPat (AsPat name pat)
= parens (hcat [ppr name, char '@', ppr pat])
+pprOutPat (SigPat pat ty _) = ppr pat <+> dcolon <+> ppr ty
+
pprOutPat (ConPat name ty [] [] [])
= ppr name
_ -> hsep [ppr name, interppSP tyvars, interppSP dicts, interppSP pats]
pprOutPat (ListPat ty pats) = brackets (interpp'SP pats)
+pprOutPat (PArrPat ty pats) = pabrackets (interpp'SP pats)
pprOutPat (TuplePat pats boxity) = tupleParens boxity (interpp'SP pats)
pprOutPat (RecPat con ty tvs dicts rpats)
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])
+ = parens (hcat [ppr n, char '+', integer k])
pprOutPat (DictPat dicts methods)
= parens (sep [ptext SLIT("{-dict-}"),
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 (PArrPat _ _) = False
failureFreePat (TuplePat pats _) = all failureFreePat pats
failureFreePat (DictPat _ _) = True
failureFreePat other_pat = False -- Literals, NPat
isConPat (AsPat _ pat) = isConPat pat
isConPat (ConPat _ _ _ _ _) = True
isConPat (ListPat _ _) = True
+isConPat (PArrPat _ _) = True
isConPat (TuplePat _ _) = True
isConPat (RecPat _ _ _ _ _) = True
isConPat (DictPat ds ms) = (length ds + length ms) > 1
collectPatBinders :: InPat a -> [a]
collectPatBinders pat = collect pat []
+collectOutPatBinders :: OutPat a -> [a]
+collectOutPatBinders pat = collectOut pat []
+
collectPatsBinders :: [InPat a] -> [a]
collectPatsBinders pats = foldr collect [] pats
collect (SigPatIn pat _) bndrs = collect pat bndrs
collect (LazyPatIn pat) bndrs = collect pat bndrs
collect (AsPatIn a pat) bndrs = a : collect pat bndrs
-collect (NPlusKPatIn n _) bndrs = n : bndrs
+collect (NPlusKPatIn n _ _) bndrs = n : bndrs
+collect (NPatIn _ _) bndrs = bndrs
collect (ConPatIn c pats) bndrs = foldr collect bndrs pats
collect (ConOpPatIn p1 c f p2) bndrs = collect p1 (collect p2 bndrs)
-collect (NegPatIn pat) bndrs = collect pat bndrs
collect (ParPatIn pat) bndrs = collect pat bndrs
collect (ListPatIn pats) bndrs = foldr collect bndrs pats
+collect (PArrPatIn pats) bndrs = foldr collect bndrs pats
collect (TuplePatIn pats _) bndrs = foldr collect bndrs pats
collect (RecPatIn c fields) bndrs = foldr (\ (f,pat,_) bndrs -> collect pat bndrs) bndrs fields
+-- Generics
+collect (TypePatIn ty) bndrs = bndrs
+-- assume the type variables do not need to be bound
+
+-- collect the bounds *value* variables in renamed patterns; type variables
+-- are *not* collected
+--
+collectOut (WildPat _) bndrs = bndrs
+collectOut (VarPat var) bndrs = var : bndrs
+collectOut (LazyPat pat) bndrs = collectOut pat bndrs
+collectOut (AsPat a pat) bndrs = a : collectOut pat bndrs
+collectOut (ListPat _ pats) bndrs = foldr collectOut bndrs pats
+collectOut (PArrPat _ pats) bndrs = foldr collectOut bndrs pats
+collectOut (TuplePat pats _) bndrs = foldr collectOut bndrs pats
+collectOut (ConPat _ _ _ ds pats) bndrs = ds ++ foldr collectOut bndrs pats
+collectOut (RecPat _ _ _ ds fields) bndrs = ds ++ foldr comb bndrs fields
+ where
+ comb (_, pat, _) bndrs = collectOut pat bndrs
+collectOut (LitPat _ _) bndrs = bndrs
+collectOut (NPat _ _ _) bndrs = bndrs
+collectOut (NPlusKPat n _ _ _ _) bndrs = n : bndrs
+collectOut (DictPat ids1 ids2) bndrs = ids1 ++ ids2 ++ bndrs
\end{code}
+
+\begin{code}
+collectSigTysFromPats :: [InPat name] -> [HsType name]
+collectSigTysFromPats pats = foldr collect_pat [] pats
+
+collectSigTysFromPat :: InPat name -> [HsType name]
+collectSigTysFromPat pat = collect_pat pat []
+
+collect_pat (SigPatIn pat ty) acc = collect_pat pat (ty:acc)
+collect_pat WildPatIn acc = acc
+collect_pat (VarPatIn var) acc = acc
+collect_pat (LitPatIn _) acc = acc
+collect_pat (LazyPatIn pat) acc = collect_pat pat acc
+collect_pat (AsPatIn a pat) acc = collect_pat pat acc
+collect_pat (NPatIn _ _) acc = acc
+collect_pat (NPlusKPatIn n _ _) acc = acc
+collect_pat (ConPatIn c pats) acc = foldr collect_pat acc pats
+collect_pat (ConOpPatIn p1 c f p2) acc = collect_pat p1 (collect_pat p2 acc)
+collect_pat (ParPatIn pat) acc = collect_pat pat acc
+collect_pat (ListPatIn pats) acc = foldr collect_pat acc pats
+collect_pat (PArrPatIn pats) acc = foldr collect_pat acc pats
+collect_pat (TuplePatIn pats _) acc = foldr collect_pat acc pats
+collect_pat (RecPatIn c fields) acc = foldr (\ (f,pat,_) acc -> collect_pat pat acc) acc fields
+-- Generics
+collect_pat (TypePatIn ty) acc = ty:acc
+\end{code}
+