\begin{code}
module HsPat (
- InPat(..),
- OutPat(..),
-
- irrefutablePat, irrefutablePats,
- failureFreePat, isWildPat,
- patsAreAllCons, isConPat,
- patsAreAllLits, isLitPat,
- collectPatBinders, collectPatsBinders,
- collectSigTysFromPat, collectSigTysFromPats
+ Pat(..), InPat, OutPat, LPat,
+
+ HsConDetails(..), hsConArgs,
+
+ mkPrefixConPat, mkCharLitPat, mkNilPat,
+
+ isBangHsBind,
+ patsAreAllCons, isConPat, isSigPat, isWildPat,
+ patsAreAllLits, isLitPat, isIrrefutableHsPat
) where
#include "HsVersions.h"
--- friends:
-import HsLit ( HsLit, HsOverLit )
-import HsExpr ( HsExpr )
-import HsTypes ( HsType )
-import BasicTypes ( Fixity, Boxity, tupleParens )
+import {-# SOURCE #-} HsExpr ( SyntaxExpr )
+-- friends:
+import HsBinds ( DictBinds, HsBind(..), emptyLHsBinds, pprLHsBinds )
+import HsLit ( HsLit(HsCharPrim), HsOverLit )
+import HsTypes ( LHsType, PostTcType )
+import BasicTypes ( Boxity, tupleParens )
-- others:
-import Name ( Name )
-import Var ( Id, TyVar )
+import PprCore ( {- instance OutputableBndr TyVar -} )
+import TysWiredIn ( nilDataCon, charDataCon, charTy )
+import Var ( TyVar )
import DataCon ( DataCon, dataConTyCon )
-import Name ( isDataSymOcc, getOccName, NamedThing )
-import Maybes ( maybeToBool )
+import TyCon ( isProductTyCon )
import Outputable
-import TyCon ( maybeTyConSingleCon )
import Type ( Type )
+import SrcLoc ( Located(..), unLoc, noLoc )
\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)
-
- | NPatIn HsOverLit
-
- | 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.
-
- | ParPatIn (InPat name) -- parenthesised pattern
-
- | ListPatIn [InPat name] -- syntactic list
- -- 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
+type InPat id = LPat id -- No 'Out' constructors
+type OutPat id = LPat id -- No 'In' constructors
+
+type LPat id = Located (Pat id)
+
+data Pat id
+ = ------------ Simple patterns ---------------
+ WildPat PostTcType -- Wild card
+ | VarPat id -- Variable
+ | VarPatOut id (DictBinds id) -- Used only for overloaded Ids; the
+ -- bindings give its overloaded instances
+ | LazyPat (LPat id) -- Lazy pattern
+ | AsPat (Located id) (LPat id) -- As pattern
+ | ParPat (LPat id) -- Parenthesised pattern
+ | BangPat (LPat id) -- Bang patterng
+
+ ------------ Lists, tuples, arrays ---------------
+ | ListPat [LPat id] -- Syntactic list
+ PostTcType -- The type of the elements
+
+ | TuplePat [LPat id] -- Tuple
+ Boxity -- UnitPat is TuplePat []
+ PostTcType
+ -- You might think that the PostTcType was redundant, but it's essential
+ -- data T a where
+ -- T1 :: Int -> T Int
+ -- f :: (T a, a) -> Int
+ -- f (T1 x, z) = z
+ -- When desugaring, we must generate
+ -- f = /\a. \v::a. case v of (t::T a, w::a) ->
+ -- case t of (T1 (x::Int)) ->
+ -- Note the (w::a), NOT (w::Int), because we have not yet
+ -- refined 'a' to Int. So we must know that the second component
+ -- of the tuple is of type 'a' not Int. See selectMatchVar
+
+ | PArrPat [LPat id] -- Syntactic parallel array
+ PostTcType -- The type of the elements
+
+ ------------ Constructor patterns ---------------
+ | ConPatIn (Located id)
+ (HsConDetails id (LPat id))
+
+ | ConPatOut (Located DataCon)
+ [TyVar] -- Existentially bound type variables
+ [id] -- Ditto dictionaries
+ (DictBinds id) -- Bindings involving those dictionaries
+ (HsConDetails id (LPat id))
+ Type -- The type of the pattern
+
+ ------------ Literal and n+k patterns ---------------
+ | LitPat HsLit -- Used for *non-overloaded* literal patterns:
+ -- Int#, Char#, Int, Char, String, etc.
+
+ | NPat (HsOverLit id) -- ALWAYS positive
+ (Maybe (SyntaxExpr id)) -- Just (Name of 'negate') for negative
+ -- patterns, Nothing otherwise
+ (SyntaxExpr id) -- Equality checker, of type t->t->Bool
+ PostTcType -- Type of the pattern
+
+ | NPlusKPat (Located id) -- n+k pattern
+ (HsOverLit id) -- It'll always be an HsIntegral
+ (SyntaxExpr id) -- (>=) function, of type t->t->Bool
+ (SyntaxExpr id) -- Name of '-' (see RnEnv.lookupSyntaxName)
+
+ ------------ Generics ---------------
+ | TypePat (LHsType 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)
-
- | ListPat -- Syntactic list
- 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 (LPat id) -- Pattern with a type signature
+ (LHsType id)
+ | SigPatOut (LPat id) -- Pattern with a type signature
+ Type
+
+ ------------ 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
-
-JJQC-2-12-97
+HsConDetails is use both for patterns and for data type declarations
\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 (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
-
- -- 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)))]
- 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("|}")
+data HsConDetails id arg
+ = PrefixCon [arg] -- C p1 p2 p3
+ | RecCon [(Located 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}
-\begin{code}
-instance (NamedThing id, Outputable id) => Outputable (OutPat id) where
- ppr = pprOutPat
-\end{code}
+
+%************************************************************************
+%* *
+%* Printing patterns
+%* *
+%************************************************************************
\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 (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)
+instance (OutputableBndr name) => Outputable (Pat name) where
+ ppr = pprPat
+
+pprPatBndr :: OutputableBndr name => name -> SDoc
+pprPatBndr var -- Print with type info if -dppr-debug is on
= 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 (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]
+ if debugStyle sty then
+ parens (pprBndr LambdaBind var) -- Could pass the site to pprPat
+ -- but is it worth it?
+ else
+ ppr var
+
+pprPat :: (OutputableBndr name) => Pat name -> SDoc
+pprPat (VarPat var) = pprPatBndr var
+pprPat (VarPatOut var bs) = parens (pprPatBndr var <+> braces (ppr bs))
+pprPat (WildPat _) = char '_'
+pprPat (LazyPat pat) = char '~' <> ppr pat
+pprPat (BangPat pat) = char '!' <> ppr pat
+pprPat (AsPat name pat) = parens (hcat [ppr name, char '@', ppr pat])
+pprPat (ParPat pat) = parens (ppr 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 con details) = pprUserCon con details
+pprPat (ConPatOut con tvs dicts binds details _)
+ = getPprStyle $ \ sty -> -- Tiresome; in TcBinds.tcRhs we print out a
+ if debugStyle sty then -- typechecked Pat in an error message,
+ -- and we want to make sure it prints nicely
+ ppr con <+> sep [ hsep (map pprPatBndr tvs) <+> hsep (map pprPatBndr dicts),
+ pprLHsBinds binds, pprConArgs details]
+ else pprUserCon con details
+
+pprPat (LitPat s) = ppr s
+pprPat (NPat l Nothing _ _) = ppr l
+pprPat (NPat l (Just _) _ _) = char '-' <> ppr l
+pprPat (NPlusKPat n k _ _) = hcat [ppr n, char '+', ppr 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 ds ms) = parens (sep [ptext SLIT("{-dict-}"),
+ brackets (interpp'SP ds),
+ brackets (interpp'SP ms)])
+
+pprUserCon c (InfixCon p1 p2) = ppr p1 <+> ppr c <+> ppr p2
+pprUserCon c details = ppr c <+> pprConArgs details
+
+pprConArgs (PrefixCon pats) = interppSP pats
+pprConArgs (InfixCon p1 p2) = interppSP [p1,p2]
+pprConArgs (RecCon rpats) = braces (hsep (punctuate comma (map (pp_rpat) rpats)))
+ where
+ pp_rpat (v, p) = hsep [ppr v, char '=', ppr p]
+
+
+-- add parallel array brackets around a document
+--
+pabrackets :: SDoc -> SDoc
+pabrackets p = ptext SLIT("[:") <> p <> ptext SLIT(":]")
+\end{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 '+', integer k])
+%************************************************************************
+%* *
+%* Building patterns
+%* *
+%************************************************************************
+
+\begin{code}
+mkPrefixConPat :: DataCon -> [OutPat id] -> Type -> OutPat id
+-- Make a vanilla Prefix constructor pattern
+mkPrefixConPat dc pats ty = noLoc $ ConPatOut (noLoc dc) [] [] emptyLHsBinds (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 :: Char -> OutPat id
+mkCharLitPat c = mkPrefixConPat charDataCon [noLoc $ 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''
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 (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 (ListPat _ _) = True
-isConPat (TuplePat _ _) = True
-isConPat (RecPat _ _ _ _ _) = True
-isConPat (DictPat ds ms) = (length ds + length ms) > 1
-isConPat other = False
-
-patsAreAllLits :: [OutPat 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
-\end{code}
+isConPat (AsPat _ pat) = isConPat (unLoc pat)
+isConPat (ConPatIn _ _) = True
+isConPat (ConPatOut _ _ _ _ _ _) = True
+isConPat (ListPat _ _) = True
+isConPat (PArrPat _ _) = True
+isConPat (TuplePat _ _ _) = True
+isConPat (DictPat ds ms) = (length ds + length ms) > 1
+isConPat other = False
-This function @collectPatBinders@ works with the ``collectBinders''
-functions for @HsBinds@, etc. The order in which the binders are
-collected is important; see @HsBinds.lhs@.
+isSigPat (SigPatIn _ _) = True
+isSigPat (SigPatOut _ _) = True
+isSigPat other = False
-\begin{code}
-collectPatBinders :: InPat a -> [a]
-collectPatBinders pat = collect pat []
-
-collectPatsBinders :: [InPat 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 (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 (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}
+patsAreAllLits :: [Pat id] -> Bool
+patsAreAllLits pat_list = all isLitPat pat_list
-\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 (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
+isLitPat (AsPat _ pat) = isLitPat (unLoc pat)
+isLitPat (LitPat _) = True
+isLitPat (NPat _ _ _ _) = True
+isLitPat (NPlusKPat _ _ _ _) = True
+isLitPat other = False
+
+isBangHsBind :: HsBind id -> Bool
+-- In this module because HsPat is above HsBinds in the import graph
+isBangHsBind (PatBind { pat_lhs = L _ (BangPat p) }) = True
+isBangHsBind bind = False
+
+isIrrefutableHsPat :: LPat id -> Bool
+-- This function returns False if it's in doubt; specifically
+-- on a ConPatIn it doesn't know the size of the constructor family
+-- But if it returns True, the pattern is definitely irrefutable
+isIrrefutableHsPat pat
+ = go pat
+ where
+ go (L _ pat) = go1 pat
+
+ go1 (WildPat _) = True
+ go1 (VarPat _) = True
+ go1 (VarPatOut _ _) = True
+ go1 (LazyPat pat) = True
+ go1 (BangPat pat) = go pat
+ go1 (ParPat pat) = go pat
+ go1 (AsPat _ pat) = go pat
+ go1 (SigPatIn pat _) = go pat
+ go1 (SigPatOut pat _) = go pat
+ go1 (TuplePat pats _ _) = all go pats
+ go1 (ListPat pats _) = False
+ go1 (PArrPat pats _) = False -- ?
+
+ go1 (ConPatIn _ _) = False -- Conservative
+ go1 (ConPatOut (L _ con) _ _ _ details _)
+ = isProductTyCon (dataConTyCon con)
+ && all go (hsConArgs details)
+
+ go1 (LitPat _) = False
+ go1 (NPat _ _ _ _) = False
+ go1 (NPlusKPat _ _ _ _) = False
+
+ go1 (TypePat _) = panic "isIrrefutableHsPat: type pattern"
+ go1 (DictPat _ _) = panic "isIrrefutableHsPat: type pattern"
\end{code}
projects / ghc-hetmet.git / blobdiff