failureFreePat, isWildPat,
patsAreAllCons, isConPat,
patsAreAllLits, isLitPat,
- collectPatBinders, collectPatsBinders
+ collectPatBinders, collectPatsBinders,
+ collectSigTysFromPats
) where
#include "HsVersions.h"
-- friends:
-import HsBasic ( HsLit )
+import HsLit ( HsLit, HsOverLit )
import HsExpr ( HsExpr )
import HsTypes ( HsType )
import BasicTypes ( Fixity, Boxity, tupleParens )
Fixity -- c.f. OpApp in HsExpr
(InPat name)
- | NPlusKPatIn name -- n+k pattern
- HsLit
+ | NPatIn HsOverLit
+
+ | NPlusKPatIn name -- n+k pattern
+ HsOverLit -- It'll always be an HsIntegral
-- 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
| 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
+ | ListPat -- Syntactic list
+ 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
+ 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 HsInt, 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 (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("|}")
\end{code}
\begin{code}
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-}"),
collect (LazyPatIn pat) bndrs = collect pat bndrs
collect (AsPatIn a pat) bndrs = a : collect pat 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 (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
+\end{code}
+
+\begin{code}
+collectSigTysFromPats :: [InPat name] -> [HsType name]
+collectSigTysFromPats pats = foldr collect_pat [] pats
+
+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 (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}
+
projects / ghc-hetmet.git / blobdiff