X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FhsSyn%2FHsPat.lhs;h=6027377e3688ca39d3bc5804eef341420ed87568;hb=f6c31c0fbf77b1c46c508fa56214361671ccfd05;hp=97be698308126c71f4ca86a5970946acc907b301;hpb=fd7d044fe32e5685b35f16833b81794a61a98bc7;p=ghc-hetmet.git diff --git a/ghc/compiler/hsSyn/HsPat.lhs b/ghc/compiler/hsSyn/HsPat.lhs index 97be698..6027377 100644 --- a/ghc/compiler/hsSyn/HsPat.lhs +++ b/ghc/compiler/hsSyn/HsPat.lhs @@ -5,189 +5,192 @@ \begin{code} module HsPat ( - InPat(..), - OutPat(..), + Pat(..), InPat, OutPat, + + HsConDetails(..), hsConArgs, - irrefutablePat, irrefutablePats, - failureFreePat, isWildPat, - patsAreAllCons, isConPat, + mkPrefixConPat, mkCharLitPat, mkNilPat, + + isWildPat, + patsAreAllCons, isConPat, isSigPat, patsAreAllLits, isLitPat, - collectPatBinders, collectOutPatBinders, collectPatsBinders, + collectPatBinders, collectPatsBinders, collectSigTysFromPat, collectSigTysFromPats ) where #include "HsVersions.h" --- friends: -import HsLit ( HsLit, HsOverLit ) -import HsExpr ( HsExpr ) -import HsTypes ( HsType ) -import BasicTypes ( Fixity, Boxity, tupleParens ) +import {-# SOURCE #-} HsExpr ( HsExpr ) +-- friends: +import HsLit ( HsLit(HsCharPrim), HsOverLit ) +import HsTypes ( HsType, SyntaxName, PostTcType ) +import BasicTypes ( Boxity, tupleParens ) -- others: -import Name ( Name ) -import Var ( Id, TyVar ) -import DataCon ( DataCon, dataConTyCon ) -import Name ( isDataSymOcc, getOccName, NamedThing ) -import Maybes ( maybeToBool ) +import TysWiredIn ( nilDataCon, charDataCon, charTy ) +import Var ( TyVar ) +import DataCon ( DataCon ) import Outputable -import TyCon ( maybeTyConSingleCon ) import Type ( Type ) \end{code} -Patterns come in distinct before- and after-typechecking flavo(u)rs. + \begin{code} -data InPat name - = WildPatIn -- wild card - | VarPatIn name -- variable - | LitPatIn HsLit -- literal - | LazyPatIn (InPat name) -- lazy pattern - | AsPatIn name -- as pattern - (InPat name) - | SigPatIn (InPat name) - (HsType name) - | ConPatIn name -- constructed type - [InPat name] - | ConOpPatIn (InPat name) - name - Fixity -- c.f. OpApp in HsExpr - (InPat name) +type InPat id = Pat id -- No 'Out' constructors +type OutPat id = Pat id -- No 'In' constructors + +data Pat id + = ------------ Simple patterns --------------- + WildPat PostTcType -- Wild card + | VarPat id -- Variable + | LazyPat (Pat id) -- Lazy pattern + | AsPat id (Pat id) -- As pattern + | ParPat (Pat id) -- Parenthesised pattern + + ------------ Lists, tuples, arrays --------------- + | ListPat [Pat id] -- Syntactic list + PostTcType -- The type of the elements + + | TuplePat [Pat id] -- Tuple + Boxity -- UnitPat is TuplePat [] + + | PArrPat [Pat id] -- Syntactic parallel array + PostTcType -- The type of the elements + + ------------ Constructor patterns --------------- + | ConPatIn id + (HsConDetails id (Pat id)) + + | ConPatOut DataCon + (HsConDetails id (Pat id)) + Type -- The type of the pattern + [TyVar] -- Existentially bound type variables + [id] -- Ditto dictionaries + + ------------ Literal and n+k patterns --------------- + | LitPat HsLit -- Used for *non-overloaded* literal patterns: + -- Int#, Char#, Int, Char, String, etc. | NPatIn HsOverLit -- Always positive - (Maybe Name) -- Just (Name of 'negate') for negative + (Maybe SyntaxName) -- Just (Name of 'negate') for negative -- patterns, Nothing otherwise - -- (see RnEnv.lookupSyntaxName) - | NPlusKPatIn name -- n+k pattern + | NPatOut HsLit -- Used for literal patterns where there's an equality function to call + -- The literal is retained so that the desugarer can readily identify + -- equations with identical literal-patterns + -- Always HsInteger, HsRat or HsString. + -- Always HsInteger, HsRat or HsString. + -- *Unlike* NPatIn, for negative literals, the + -- literal is acutally negative! + Type -- Type of pattern, t + (HsExpr id) -- Of type t -> Bool; detects match + + | NPlusKPatIn id -- 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. + SyntaxName -- Name of '-' (see RnEnv.lookupSyntaxName) - | 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?) + | NPlusKPatOut id + Integer + (HsExpr id) -- Of type t -> Bool; detects match + (HsExpr id) -- Of type t -> t; subtracts k - | RecPatIn name -- record - [(name, InPat name, Bool)] -- True <=> source used punning --- Generics - | TypePatIn (HsType name) -- Type pattern for generic definitions + ------------ Generics --------------- + | TypePat (HsType id) -- Type pattern for generic definitions -- e.g f{| a+b |} = ... - -- These show up only in class - -- declarations, + -- 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) - | LazyPat (OutPat id) -- lazy pattern - | AsPat id -- as pattern - (OutPat id) - - | 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 - Boxity - -- UnitPat is TuplePat [] - - | ConPat DataCon - Type -- the type of the pattern - [TyVar] -- Existentially bound type variables - [id] -- Ditto dictionaries - [OutPat id] - - -- ConOpPats are only used on the input side - - | 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 - - | 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 - -- Always HsInteger, HsRat or HsString. - Type -- Type of pattern, t - (HsExpr id (OutPat id)) -- Of type t -> Bool; detects match - - | NPlusKPat id - 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 + ------------ Pattern type signatures --------------- + | SigPatIn (Pat id) -- Pattern with a type signature + (HsType id) + | SigPatOut (Pat id) -- Pattern p + Type -- Type, t, of the whole pattern + (HsExpr id) -- Coercion function, + -- of type t -> typeof(p) + + ------------ Dictionary patterns (translation only) --------------- | 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 +HsConDetails is use both for patterns and for data type declarations + +\begin{code} +data HsConDetails id arg + = PrefixCon [arg] -- C p1 p2 p3 + | RecCon [(id, arg)] -- C { x = p1, y = p2 } + | InfixCon arg arg -- p1 `C` p2 + +hsConArgs :: HsConDetails id arg -> [arg] +hsConArgs (PrefixCon ps) = ps +hsConArgs (RecCon fs) = map snd fs +hsConArgs (InfixCon p1 p2) = [p1,p2] +\end{code} -JJQC-2-12-97 + +%************************************************************************ +%* * +%* Printing patterns +%* * +%************************************************************************ \begin{code} -instance (Outputable name) => Outputable (InPat name) where - ppr = pprInPat - -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 (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 - | otherwise = hsep [ppr c, interppSP pats] -- inner ParPats supply the necessary parens. - -pprInPat (ConOpPatIn pat1 op fixity pat2) - = hsep [ppr pat1, ppr op, ppr pat2] -- ParPats put in parens +instance (OutputableBndr name) => Outputable (Pat name) where + ppr = pprPat +pprPat :: (OutputableBndr name) => Pat name -> SDoc + +pprPat (VarPat var) -- Print with type info if -dppr-debug is on + = getPprStyle $ \ sty -> + if debugStyle sty then + parens (pprBndr LambdaBind var) -- Could pass the site to pprPat + -- but is it worth it? + else + ppr var + +pprPat (WildPat _) = char '_' +pprPat (LazyPat pat) = char '~' <> ppr pat +pprPat (AsPat name pat) = parens (hcat [ppr name, char '@', ppr pat]) +pprPat (ParPat pat) = parens (pprPat pat) + +pprPat (ListPat pats _) = brackets (interpp'SP pats) +pprPat (PArrPat pats _) = pabrackets (interpp'SP pats) +pprPat (TuplePat pats bx) = tupleParens bx (interpp'SP pats) + +pprPat (ConPatIn c details) = pprConPat c details +pprPat (ConPatOut c details _ _ _) = pprConPat c details + +pprPat (LitPat s) = ppr s +pprPat (NPatIn l _) = ppr l +pprPat (NPatOut l _ _) = ppr l +pprPat (NPlusKPatIn n k _) = hcat [ppr n, char '+', ppr k] +pprPat (NPlusKPatOut n k _ _) = hcat [ppr n, char '+', integer k] + +pprPat (TypePat ty) = ptext SLIT("{|") <> ppr ty <> ptext SLIT("|}") + +pprPat (SigPatIn pat ty) = ppr pat <+> dcolon <+> ppr ty +pprPat (SigPatOut pat ty _) = ppr pat <+> dcolon <+> ppr ty + +pprPat (DictPat dicts methods) + = parens (sep [ptext SLIT("{-dict-}"), + brackets (interpp'SP dicts), + brackets (interpp'SP methods)]) + + + +pprConPat con (PrefixCon pats) = ppr con <+> interppSP pats -- inner ParPats supply the necessary parens. +pprConPat con (InfixCon pat1 pat2) = hsep [ppr pat1, ppr con, 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 (RecPatIn con rpats) - = hsep [ppr con, braces (hsep (punctuate comma (map (pp_rpat) rpats)))] +pprConPat con (RecCon rpats) + = 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] + 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 -- @@ -195,61 +198,32 @@ pabrackets :: SDoc -> SDoc pabrackets p = ptext SLIT("[:") <> p <> ptext SLIT(":]") \end{code} -\begin{code} -instance (NamedThing id, Outputable id) => Outputable (OutPat id) where - ppr = pprOutPat -\end{code} - -\begin{code} -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 (SigPat pat ty _) = ppr pat <+> dcolon <+> ppr ty - -pprOutPat (ConPat name ty [] [] []) - = ppr name - --- Kludge to get infix constructors to come out right --- when ppr'ing desugar warnings. -pprOutPat (ConPat name ty tyvars dicts pats) - = getPprStyle $ \ sty -> - parens $ - case pats of - [p1,p2] - | userStyle sty && isDataSymOcc (getOccName name) -> - hsep [ppr p1, ppr name, ppr p2] - _ -> 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) - = hsep [ppr con, interppSP tvs, interppSP dicts, 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] +%************************************************************************ +%* * +%* Building patterns +%* * +%************************************************************************ -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 '+', integer k]) +\begin{code} +mkPrefixConPat :: DataCon -> [OutPat id] -> Type -> OutPat id +-- Make a vanilla Prefix constructor pattern +mkPrefixConPat dc pats ty = ConPatOut dc (PrefixCon pats) ty [] [] -pprOutPat (DictPat dicts methods) - = parens (sep [ptext SLIT("{-dict-}"), - brackets (interpp'SP dicts), - brackets (interpp'SP methods)]) +mkNilPat :: Type -> OutPat id +mkNilPat ty = mkPrefixConPat nilDataCon [] ty +mkCharLitPat :: Int -> OutPat id +mkCharLitPat c = mkPrefixConPat charDataCon [LitPat (HsCharPrim c)] charTy \end{code} + %************************************************************************ %* * -%* predicates for checking things about pattern-lists in EquationInfo * +%* Predicates for checking things about pattern-lists in EquationInfo * %* * %************************************************************************ + \subsection[Pat-list-predicates]{Look for interesting things in patterns} Unlike in the Wadler chapter, where patterns are either ``variables'' @@ -274,110 +248,81 @@ patterns are treated specially, of course. The 1.3 report defines what ``irrefutable'' and ``failure-free'' patterns are. \begin{code} -irrefutablePats :: [OutPat id] -> Bool -irrefutablePats pat_list = all irrefutablePat pat_list - -irrefutablePat (AsPat _ pat) = irrefutablePat pat -irrefutablePat (WildPat _) = True -irrefutablePat (VarPat _) = True -irrefutablePat (LazyPat _) = True -irrefutablePat (DictPat ds ms) = (length ds + length ms) <= 1 -irrefutablePat other = False - -failureFreePat :: OutPat id -> 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 (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 - -only_con con = maybeToBool (maybeTyConSingleCon (dataConTyCon con)) -\end{code} - -\begin{code} isWildPat (WildPat _) = True isWildPat other = False -patsAreAllCons :: [OutPat id] -> Bool +patsAreAllCons :: [Pat id] -> Bool patsAreAllCons pat_list = all isConPat pat_list isConPat (AsPat _ pat) = isConPat pat -isConPat (ConPat _ _ _ _ _) = True +isConPat (ConPatIn _ _) = True +isConPat (ConPatOut _ _ _ _ _) = True isConPat (ListPat _ _) = True isConPat (PArrPat _ _) = True isConPat (TuplePat _ _) = True -isConPat (RecPat _ _ _ _ _) = True isConPat (DictPat ds ms) = (length ds + length ms) > 1 isConPat other = False -patsAreAllLits :: [OutPat id] -> Bool +isSigPat (SigPatIn _ _) = True +isSigPat (SigPatOut _ _ _) = True +isSigPat other = False + +patsAreAllLits :: [Pat id] -> Bool patsAreAllLits pat_list = all isLitPat pat_list -isLitPat (AsPat _ pat) = isLitPat pat -isLitPat (LitPat _ _) = True -isLitPat (NPat _ _ _) = True -isLitPat (NPlusKPat _ _ _ _ _) = True -isLitPat other = False +isLitPat (AsPat _ pat) = isLitPat pat +isLitPat (LitPat _) = True +isLitPat (NPatIn _ _) = True +isLitPat (NPatOut _ _ _) = True +isLitPat (NPlusKPatIn _ _ _) = True +isLitPat (NPlusKPatOut _ _ _ _) = True +isLitPat other = False \end{code} +%************************************************************************ +%* * +%* Gathering stuff out of patterns +%* * +%************************************************************************ + This function @collectPatBinders@ works with the ``collectBinders'' functions for @HsBinds@, etc. The order in which the binders are collected is important; see @HsBinds.lhs@. +It collects the bounds *value* variables in renamed patterns; type variables +are *not* collected. + \begin{code} -collectPatBinders :: InPat a -> [a] +collectPatBinders :: Pat a -> [a] collectPatBinders pat = collect pat [] -collectOutPatBinders :: OutPat a -> [a] -collectOutPatBinders pat = collectOut pat [] - -collectPatsBinders :: [InPat a] -> [a] +collectPatsBinders :: [Pat a] -> [a] collectPatsBinders pats = foldr collect [] pats -collect WildPatIn bndrs = bndrs -collect (VarPatIn var) bndrs = var : bndrs -collect (LitPatIn _) bndrs = bndrs -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 (WildPat _) bndrs = bndrs +collect (VarPat var) bndrs = var : bndrs +collect (LazyPat pat) bndrs = collect pat bndrs +collect (AsPat a pat) bndrs = a : collect pat bndrs +collect (ParPat pat) bndrs = collect pat bndrs + +collect (ListPat pats _) bndrs = foldr collect bndrs pats +collect (PArrPat pats _) bndrs = foldr collect bndrs pats +collect (TuplePat pats _) bndrs = foldr collect bndrs pats + +collect (ConPatIn c ps) bndrs = foldr collect bndrs (hsConArgs ps) +collect (ConPatOut c ps _ _ ds) bndrs = ds ++ foldr collect bndrs (hsConArgs ps) + +collect (LitPat _) bndrs = 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 (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 +collect (NPatOut _ _ _) bndrs = bndrs + +collect (NPlusKPatIn n _ _) bndrs = n : bndrs +collect (NPlusKPatOut n _ _ _) bndrs = n : bndrs + +collect (SigPatIn pat _) bndrs = collect pat bndrs +collect (SigPatOut pat _ _) bndrs = collect pat bndrs +collect (TypePat ty) bndrs = bndrs +collect (DictPat ids1 ids2) bndrs = ids1 ++ ids2 ++ bndrs \end{code} \begin{code} @@ -387,22 +332,16 @@ 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 +collect_pat (SigPatIn pat ty) acc = collect_pat pat (ty:acc) +collect_pat (TypePat ty) acc = ty:acc + +collect_pat (LazyPat pat) acc = collect_pat pat acc +collect_pat (AsPat a pat) acc = collect_pat pat acc +collect_pat (ParPat pat) acc = collect_pat pat acc +collect_pat (ListPat pats _) acc = foldr collect_pat acc pats +collect_pat (PArrPat pats _) acc = foldr collect_pat acc pats +collect_pat (TuplePat pats _) acc = foldr collect_pat acc pats +collect_pat (ConPatIn c ps) acc = foldr collect_pat acc (hsConArgs ps) +collect_pat other acc = acc -- Literals, vars, wildcard \end{code}