purescript · rhendric · May 29, 2022
diff --git a/CHANGELOG.d/feature_leading-and-trailing-delimiters.md b/CHANGELOG.d/feature_leading-and-trailing-delimiters.md
@@ -0,0 +1,15 @@
+* Allow leading and trailing delimiters in many syntax positions
+
+  PureScript's syntax contains multiple places where sequences of words or
+  clauses are expected, delimited by commas or vertical bars. To
+  facilitate editing these elements when placed on their own lines,
+  PureScript's parser now supports an optional leading or trailing
+  delimiter in most such locations, specifically:
+
+    * Array and object literals (and patterns)
+    * Sum type definitions
+    * Object updates
+    * Row types
+    * Import and export lists
+    * Functional dependencies
+    * Compound constraints and superclasses
diff --git a/src/Language/PureScript/CST/Convert.hs b/src/Language/PureScript/CST/Convert.hs
@@ -107,7 +107,7 @@ convertType fileName = go
         let ann = sourceAnnCommented fileName (lblTok a) (snd $ typeRange ty)
         T.RCons ann (L.Label $ lblName a) (go ty) c
     case labels of
-      Just (Separated h t) ->
+      Just (SeparatedExtra _ h t _) ->
         rowCons h $ foldr (rowCons . snd) rowTail t
       Nothing ->
         rowTail
@@ -276,7 +276,7 @@ convertExpr fileName = go
       let
         ann = sourceAnnCommented fileName a c
         vals = case bs of
-          Just (Separated x xs) -> go x : (go . snd <$> xs)
+          Just (SeparatedExtra _ x xs _) -> go x : (go . snd <$> xs)
           Nothing -> []
       positioned ann . AST.Literal (fst ann) $ AST.ArrayLiteral vals
     ExprRecord z (Wrapped a bs c) -> do
@@ -286,7 +286,7 @@ convertExpr fileName = go
           RecordPun f -> (mkString . getIdent $ nameValue f, go . ExprIdent z $ QualifiedName (nameTok f) Nothing (nameValue f))
           RecordField f _ v -> (lblName f, go v)
         vals = case bs of
-          Just (Separated x xs) -> lbl x : (lbl . snd <$> xs)
+          Just (SeparatedExtra _ x xs _) -> lbl x : (lbl . snd <$> xs)
           Nothing -> []
       positioned ann . AST.Literal (fst ann) $ AST.ObjectLiteral vals
     ExprParens _ (Wrapped a b c) ->
@@ -399,7 +399,7 @@ convertBinder fileName = go
       let
         ann = sourceAnnCommented fileName a c
         vals = case bs of
-          Just (Separated x xs) -> go x : (go . snd <$> xs)
+          Just (SeparatedExtra _ x xs _) -> go x : (go . snd <$> xs)
           Nothing -> []
       positioned ann . AST.LiteralBinder (fst ann) $ AST.ArrayLiteral vals
     BinderRecord z (Wrapped a bs c) -> do
@@ -409,7 +409,7 @@ convertBinder fileName = go
           RecordPun f -> (mkString . getIdent $ nameValue f, go $ BinderVar z f)
           RecordField f _ v -> (lblName f, go v)
         vals = case bs of
-          Just (Separated x xs) -> lbl x : (lbl . snd <$> xs)
+          Just (SeparatedExtra _ x xs _) -> lbl x : (lbl . snd <$> xs)
           Nothing -> []
       positioned ann . AST.LiteralBinder (fst ann) $ AST.ObjectLiteral vals
     BinderParens _ (Wrapped a b c) ->
@@ -442,7 +442,7 @@ convertDeclaration fileName decl = case decl of
             [] -> []
             (st', ctor) : tl' -> ctrs st' ctor tl'
           )
-    pure $ AST.DataDeclaration ann Env.Data (nameValue a) (goTypeVar <$> vars) (maybe [] (\(st, Separated hd tl) -> ctrs st hd tl) bd)
+    pure $ AST.DataDeclaration ann Env.Data (nameValue a) (goTypeVar <$> vars) (maybe [] (\(st, SeparatedExtra _ hd tl _) -> ctrs st hd tl) bd)
   DeclType _ (DataHead _ a vars) _ bd ->
     pure $ AST.TypeSynonymDeclaration ann
       (nameValue a)

diff --git a/src/Language/PureScript/CST/Flatten.hs b/src/Language/PureScript/CST/Flatten.hs
@@ -10,7 +10,7 @@ flattenModule :: Module a -> DList SourceToken
 flattenModule m@(Module _ a b c d e f g) =
   pure a <>
   flattenName b <>
-  foldMap (flattenWrapped (flattenSeparated flattenExport)) c <>
+  foldMap (flattenWrapped (flattenSeparatedExtra flattenExport)) c <>
   pure d <>
   foldMap flattenImportDecl e <>
   foldMap flattenDeclaration f <>
@@ -32,7 +32,7 @@ flattenClassHead (ClassHead a b c d e) =
   foldMap (\(f, g) -> flattenOneOrDelimited flattenConstraint f <> pure g) b <>
   flattenName c <>
   foldMap flattenTypeVarBinding d <>
-  foldMap (\(f, g) -> pure f <> flattenSeparated flattenClassFundep g) e
+  foldMap (\(f, g) -> pure f <> flattenSeparatedExtra flattenClassFundep g) e
 
 flattenClassFundep :: ClassFundep -> DList SourceToken
 flattenClassFundep = \case
@@ -74,9 +74,9 @@ flattenBinder = \case
   BinderChar _ a _ -> pure a
   BinderString _ a _ -> pure a
   BinderNumber _ a b _ -> foldMap pure a <> pure b
-  BinderArray _ a -> flattenWrapped (foldMap (flattenSeparated flattenBinder)) a
+  BinderArray _ a -> flattenWrapped (foldMap (flattenSeparatedExtra flattenBinder)) a
   BinderRecord _ a ->
-    flattenWrapped (foldMap (flattenSeparated (flattenRecordLabeled flattenBinder))) a
+    flattenWrapped (foldMap (flattenSeparatedExtra (flattenRecordLabeled flattenBinder))) a
   BinderParens _ a -> flattenWrapped flattenBinder a
   BinderTyped _ a b c -> flattenBinder a <> pure b <> flattenType c
   BinderOp _ a b c -> flattenBinder a <> flattenQualifiedName b <> flattenBinder c
@@ -94,7 +94,7 @@ flattenRecordUpdate :: RecordUpdate a -> DList SourceToken
 flattenRecordUpdate = \case
   RecordUpdateLeaf a b c -> flattenLabel a <> pure b <> flattenExpr c
   RecordUpdateBranch a b ->
-    flattenLabel a <> flattenWrapped (flattenSeparated flattenRecordUpdate) b
+    flattenLabel a <> flattenWrapped (flattenSeparatedExtra flattenRecordUpdate) b
 
 flattenLambda :: Lambda a -> DList SourceToken
 flattenLambda (Lambda a b c d) =
@@ -139,17 +139,17 @@ flattenExpr = \case
   ExprChar _ a _ -> pure a
   ExprString _ a _ -> pure a
   ExprNumber _ a _ -> pure a
-  ExprArray _ a -> flattenWrapped (foldMap (flattenSeparated flattenExpr)) a
+  ExprArray _ a -> flattenWrapped (foldMap (flattenSeparatedExtra flattenExpr)) a
   ExprRecord _ a ->
-    flattenWrapped (foldMap (flattenSeparated (flattenRecordLabeled flattenExpr))) a
+    flattenWrapped (foldMap (flattenSeparatedExtra (flattenRecordLabeled flattenExpr))) a
   ExprParens _ a -> flattenWrapped flattenExpr a
   ExprTyped _ a b c -> flattenExpr a <> pure b <> flattenType c
   ExprInfix _ a b c -> flattenExpr a <> flattenWrapped flattenExpr b <> flattenExpr c
   ExprOp _ a b c -> flattenExpr a <> flattenQualifiedName b <> flattenExpr c
   ExprOpName _ a -> flattenQualifiedName a
   ExprNegate _ a b -> pure a <> flattenExpr b
   ExprRecordAccessor _ a -> flattenRecordAccessor a
-  ExprRecordUpdate _ a b -> flattenExpr a <> flattenWrapped (flattenSeparated flattenRecordUpdate) b
+  ExprRecordUpdate _ a b -> flattenExpr a <> flattenWrapped (flattenSeparatedExtra flattenRecordUpdate) b
   ExprApp _ a b -> flattenExpr a <> flattenExpr b
   ExprLambda _ a -> flattenLambda a
   ExprIf _ a -> flattenIfThenElse a
@@ -206,7 +206,7 @@ flattenDeclaration :: Declaration a -> DList SourceToken
 flattenDeclaration = \case
   DeclData _ a b ->
     flattenDataHead a <>
-    foldMap (\(t, cs) -> pure t <> flattenSeparated flattenDataCtor cs) b
+    foldMap (\(t, cs) -> pure t <> flattenSeparatedExtra flattenDataCtor cs) b
   DeclType _ a b c ->flattenDataHead a <> pure b <> flattenType c
   DeclNewtype _ a b c d -> flattenDataHead a <> pure b <> flattenName c <> flattenType d
   DeclClass _ a b ->
@@ -242,14 +242,14 @@ flattenExport = \case
 flattenDataMembers :: DataMembers a -> DList SourceToken
 flattenDataMembers = \case
   DataAll _ t -> pure t
-  DataEnumerated _ ns -> flattenWrapped (foldMap (flattenSeparated flattenName)) ns
+  DataEnumerated _ ns -> flattenWrapped (foldMap (flattenSeparatedExtra flattenName)) ns
 
 flattenImportDecl :: ImportDecl a -> DList SourceToken
 flattenImportDecl (ImportDecl _ a b c d) =
   pure a <>
   flattenName b <>
   foldMap (\(mt, is) ->
-             foldMap pure mt <> flattenWrapped (flattenSeparated flattenImport) is) c <>
+             foldMap pure mt <> flattenWrapped (flattenSeparatedExtra flattenImport) is) c <>
   foldMap (\(t, n) -> pure t <> flattenName n) d
 
 flattenImport :: Import a -> DList SourceToken
@@ -266,11 +266,14 @@ flattenWrapped k (Wrapped a b c) = pure a <> k b <> pure c
 flattenSeparated :: (a -> DList SourceToken) -> Separated a -> DList SourceToken
 flattenSeparated k (Separated a b) = k a <> foldMap (\(c, d) -> pure c <> k d) b
 
+flattenSeparatedExtra :: (a -> DList SourceToken) -> SeparatedExtra a -> DList SourceToken
+flattenSeparatedExtra k (SeparatedExtra a b c d) = foldMap pure a <> k b <> foldMap (\(e, f) -> pure e <> k f) c <> foldMap pure d
+
 flattenOneOrDelimited
   :: (a -> DList SourceToken) -> OneOrDelimited a -> DList SourceToken
 flattenOneOrDelimited f = \case
   One a -> f a
-  Many a -> flattenWrapped (flattenSeparated f) a
+  Many a -> flattenWrapped (flattenSeparatedExtra f) a
 
 flattenLabeled :: (a -> DList SourceToken) -> (b -> DList SourceToken) -> Labeled a b -> DList SourceToken
 flattenLabeled ka kc (Labeled a b c) = ka a <> pure b <> kc c
@@ -298,7 +301,7 @@ flattenType = \case
 
 flattenRow :: Row a -> DList SourceToken
 flattenRow (Row lbls tl) =
-  foldMap (flattenSeparated (flattenLabeled (pure . lblTok) flattenType)) lbls
+  foldMap (flattenSeparatedExtra (flattenLabeled (pure . lblTok) flattenType)) lbls
     <> foldMap (\(a, b) -> pure a <> flattenType b) tl
 
 flattenTypeVarBinding :: TypeVarBinding a -> DList SourceToken

diff --git a/src/Language/PureScript/CST/Parser.y b/src/Language/PureScript/CST/Parser.y
@@ -167,13 +167,18 @@ manyOrEmpty(a) :: { [a] }
 sep(a, s) :: { Separated a }
   : sep1(a, s) { separated $1 }
 
+sepx(a, s) :: { SeparatedExtra a }
+  : sep1(a, s) { separatedExtra Nothing Nothing $1 }
+  | sep1(a, s) s { separatedExtra Nothing (Just $2) $1 }
+  | s sep1(a, s) { separatedExtra (Just $1) Nothing $2 }
+
 sep1(a, s) :: { [(SourceToken, a)] }
   : a %shift { [(placeholder, $1)] }
   | sep1(a, s) s a { ($2, $3) : $1 }
 
 delim(a, b, c, d) :: { Delimited b }
   : a d { Wrapped $1 Nothing $2 }
-  | a sep(b, c) d { Wrapped $1 (Just $2) $3 }
+  | a sepx(b, c) d { Wrapped $1 (Just $2) $3 }
 
 moduleName :: { Name N.ModuleName }
   : UPPER {% upperToModuleName $1 }
@@ -340,8 +345,8 @@ typeKindedAtom :: { Type () }
 row :: { Row () }
   : {- empty -} { Row Nothing Nothing }
   | '|' type { Row Nothing (Just ($1, $2)) }
-  | sep(rowLabel, ',') { Row (Just $1) Nothing }
-  | sep(rowLabel, ',') '|' type { Row (Just $1) (Just ($2, $3)) }
+  | sepx(rowLabel, ',') { Row (Just $1) Nothing }
+  | sepx(rowLabel, ',') '|' type { Row (Just $1) (Just ($2, $3)) }
 
 rowLabel :: { Labeled Label (Type ()) }
   : label '::' type { Labeled $1 $2 $3 }
@@ -409,7 +414,7 @@ expr5 :: { Expr () }
 expr6 :: { Expr () }
   : expr7 %shift { $1 }
   | expr7 '{' '}' { ExprApp () $1 (ExprRecord () (Wrapped $2 Nothing $3)) }
-  | expr7 '{' sep(recordUpdateOrLabel, ',') '}'
+  | expr7 '{' sepx(recordUpdateOrLabel, ',') '}'
       {% toRecordFields $3 >>= \case
           Left xs -> pure $ ExprApp () $1 (ExprRecord () (Wrapped $2 (Just xs) $4))
           Right xs -> pure $ ExprRecordUpdate () $1 (Wrapped $2 xs $4)
@@ -442,11 +447,11 @@ recordUpdateOrLabel :: { Either (RecordLabeled (Expr ())) (RecordUpdate ()) }
   : label ':' expr { Left (RecordField $1 $2 $3) }
   | label {% fmap (Left . RecordPun) . toName Ident $ lblTok $1 }
   | label '=' expr { Right (RecordUpdateLeaf $1 $2 $3) }
-  | label '{' sep(recordUpdate, ',') '}' { Right (RecordUpdateBranch $1 (Wrapped $2 $3 $4)) }
+  | label '{' sepx(recordUpdate, ',') '}' { Right (RecordUpdateBranch $1 (Wrapped $2 $3 $4)) }
 
 recordUpdate :: { RecordUpdate () }
   : label '=' expr { RecordUpdateLeaf $1 $2 $3 }
-  | label '{' sep(recordUpdate, ',') '}' { RecordUpdateBranch $1 (Wrapped $2 $3 $4) }
+  | label '{' sepx(recordUpdate, ',') '}' { RecordUpdateBranch $1 (Wrapped $2 $3 $4) }
 
 letBinding :: { LetBinding () }
   : ident '::' type { LetBindingSignature () (Labeled $1 $2 $3) }
@@ -620,7 +625,7 @@ declElse :: { SourceToken }
 
 exports :: { Maybe (DelimitedNonEmpty (Export ())) }
   : {- empty -} { Nothing }
-  | '(' sep(export, ',') ')' { Just (Wrapped $1 $2 $3) }
+  | '(' sepx(export, ',') ')' { Just (Wrapped $1 $2 $3) }
 
 export :: { Export () }
   : ident { ExportValue () $1 }
@@ -634,16 +639,16 @@ export :: { Export () }
 dataMembers :: { (DataMembers ()) }
  : '(..)' { DataAll () $1 }
  | '(' ')' { DataEnumerated () (Wrapped $1 Nothing $2) }
- | '(' sep(properName, ',') ')' { DataEnumerated () (Wrapped $1 (Just \$ getProperName <\$> $2) $3) }
+ | '(' sepx(properName, ',') ')' { DataEnumerated () (Wrapped $1 (Just \$ getProperName <\$> $2) $3) }
 
 importDecl :: { ImportDecl () }
   : 'import' moduleName imports { ImportDecl () $1 $2 $3 Nothing }
   | 'import' moduleName imports 'as' moduleName { ImportDecl () $1 $2 $3 (Just ($4, $5)) }
 
 imports :: { Maybe (Maybe SourceToken, DelimitedNonEmpty (Import ())) }
   : {- empty -} { Nothing }
-  | '(' sep(import, ',') ')' { Just (Nothing, Wrapped $1 $2 $3) }
-  | 'hiding' '(' sep(import, ',') ')' { Just (Just $1, Wrapped $2 $3 $4) }
+  | '(' sepx(import, ',') ')' { Just (Nothing, Wrapped $1 $2 $3) }
+  | 'hiding' '(' sepx(import, ',') ')' { Just (Just $1, Wrapped $2 $3 $4) }
 
 import :: { Import () }
   : ident { ImportValue () $1 }
@@ -655,7 +660,7 @@ import :: { Import () }
 
 decl :: { Declaration () }
   : dataHead { DeclData () $1 Nothing }
-  | dataHead '=' sep(dataCtor, '|') { DeclData () $1 (Just ($2, $3)) }
+  | dataHead '=' sepx(dataCtor, '|') { DeclData () $1 (Just ($2, $3)) }
   | typeHead '=' type {% checkNoWildcards $3 *> pure (DeclType () $1 $2 $3) }
   | newtypeHead '=' properName typeAtom {% checkNoWildcards $4 *> pure (DeclNewtype () $1 $2 (getProperName $3) $4) }
   | classHead { either id (\h -> DeclClass () h Nothing) $1 }
@@ -714,12 +719,12 @@ classSignature :: { Labeled (Name (N.ProperName 'N.TypeName)) (Type ()) }
 classSuper :: { (OneOrDelimited (Constraint ()), SourceToken) }
   : constraints '<=' {%^ revert $ pure ($1, $2) }
 
-classNameAndFundeps :: { (Name (N.ProperName 'N.ClassName), [TypeVarBinding ()], Maybe (SourceToken, Separated ClassFundep)) }
+classNameAndFundeps :: { (Name (N.ProperName 'N.ClassName), [TypeVarBinding ()], Maybe (SourceToken, SeparatedExtra ClassFundep)) }
   : properName manyOrEmpty(typeVarBinding) fundeps {%^ revert $ pure (getProperName $1, $2, $3) }
 
-fundeps :: { Maybe (SourceToken, Separated ClassFundep) }
+fundeps :: { Maybe (SourceToken, SeparatedExtra ClassFundep) }
   : {- empty -} { Nothing }
-  | '|' sep(fundep, ',') { Just ($1, $2) }
+  | '|' sepx(fundep, ',') { Just ($1, $2) }
 
 fundep :: { ClassFundep }
   : '->' many(ident) { FundepDetermined $1 $2 }
@@ -740,7 +745,7 @@ instHead :: { InstanceHead () }
 
 constraints :: { OneOrDelimited (Constraint ()) }
   : constraint { One $1 }
-  | '(' sep(constraint, ',') ')' { Many (Wrapped $1 $2 $3) }
+  | '(' sepx(constraint, ',') ')' { Many (Wrapped $1 $2 $3) }
 
 constraint :: { Constraint () }
   : qualProperName manyOrEmpty(typeAtom) {% for_ $2 checkNoWildcards *> for_ $2 checkNoForalls *> pure (Constraint () (getQualifiedProperName $1) $2) }

diff --git a/src/Language/PureScript/CST/Positions.hs b/src/Language/PureScript/CST/Positions.hs
@@ -98,6 +98,10 @@ sepLast :: Separated a -> a
 sepLast (Separated hd []) = hd
 sepLast (Separated _ tl) = snd $ last tl
 
+sepXLast :: SeparatedExtra a -> a
+sepXLast (SeparatedExtra _ hd [] _) = hd
+sepXLast (SeparatedExtra _ _ tl _) = snd $ last tl
+
 type TokenRange = (SourceToken, SourceToken)
 
 toSourceRange :: TokenRange -> SourceRange
@@ -160,7 +164,7 @@ dataMembersRange = \case
 declRange :: Declaration a -> TokenRange
 declRange = \case
   DeclData _ hd ctors
-    | Just (_, cs) <- ctors -> (fst start, snd . dataCtorRange $ sepLast cs)
+    | Just (_, cs) <- ctors -> (fst start, fromMaybe (snd . dataCtorRange $ sepXLast cs) $ sepXTrailing cs)
     | otherwise -> start
     where start = dataHeadRange hd
   DeclType _ a _ b -> (fst $ dataHeadRange a,  snd $ typeRange b)
@@ -191,7 +195,7 @@ dataCtorRange (DataCtor _ name fields)
 
 classHeadRange :: ClassHead a -> TokenRange
 classHeadRange (ClassHead kw _ name vars fdeps)
-  | Just (_, fs) <- fdeps = (kw, snd .classFundepRange $ sepLast fs)
+  | Just (_, fs) <- fdeps = (kw, fromMaybe (snd . classFundepRange $ sepXLast fs) $ sepXTrailing fs)
   | [] <- vars = (kw, snd $ nameRange name)
   | otherwise = (kw, snd . typeVarBindingRange $ last vars)
 

diff --git a/src/Language/PureScript/CST/Traversals.hs b/src/Language/PureScript/CST/Traversals.hs
@@ -4,8 +4,8 @@ import Prelude
 
 import Language.PureScript.CST.Types
 
-everythingOnSeparated :: (r -> r -> r) -> (a -> r) -> Separated a -> r
-everythingOnSeparated op k (Separated hd tl) = go hd tl
+everythingOnSeparated :: (r -> r -> r) -> (a -> r) -> SeparatedExtra a -> r
+everythingOnSeparated op k (SeparatedExtra _ hd tl _) = go hd tl
   where
   go a [] = k a
   go a (b : bs) = k a `op` go (snd b) bs
diff --git a/src/Language/PureScript/CST/Types.hs b/src/Language/PureScript/CST/Types.hs
@@ -117,14 +117,21 @@ data Separated a = Separated
   , sepTail :: [(SourceToken, a)]
   } deriving (Show, Eq, Ord, Functor, Foldable, Traversable, Generic)
 
+data SeparatedExtra a = SeparatedExtra
+  { sepXLeading :: Maybe SourceToken
+  , sepXHead :: a
+  , sepXTail :: [(SourceToken, a)]
+  , sepXTrailing :: Maybe SourceToken
+  } deriving (Show, Eq, Ord, Functor, Foldable, Traversable, Generic)
+
 data Labeled a b = Labeled
   { lblLabel :: a
   , lblSep :: SourceToken
   , lblValue  :: b
   } deriving (Show, Eq, Ord, Functor, Foldable, Traversable, Generic)
 
-type Delimited a = Wrapped (Maybe (Separated a))
-type DelimitedNonEmpty a = Wrapped (Separated a)
+type Delimited a = Wrapped (Maybe (SeparatedExtra a))
+type DelimitedNonEmpty a = Wrapped (SeparatedExtra a)
 
 data OneOrDelimited a
   = One a
@@ -163,7 +170,7 @@ data Constraint a
   deriving (Show, Eq, Ord, Functor, Foldable, Traversable, Generic)
 
 data Row a = Row
-  { rowLabels :: Maybe (Separated (Labeled Label (Type a)))
+  { rowLabels :: Maybe (SeparatedExtra (Labeled Label (Type a)))
   , rowTail :: Maybe (SourceToken, Type a)
   } deriving (Show, Eq, Ord, Functor, Foldable, Traversable, Generic)
 
@@ -193,7 +200,7 @@ data DataMembers a
   deriving (Show, Eq, Ord, Functor, Foldable, Traversable, Generic)
 
 data Declaration a
-  = DeclData a (DataHead a) (Maybe (SourceToken, Separated (DataCtor a)))
+  = DeclData a (DataHead a) (Maybe (SourceToken, SeparatedExtra (DataCtor a)))
   | DeclType a (DataHead a) SourceToken (Type a)
   | DeclNewtype a (DataHead a) SourceToken (Name (N.ProperName 'N.ConstructorName)) (Type a)
   | DeclClass a (ClassHead a) (Maybe (SourceToken, NonEmpty (Labeled (Name Ident) (Type a))))
@@ -250,7 +257,7 @@ data ClassHead a = ClassHead
   , clsSuper :: Maybe (OneOrDelimited (Constraint a), SourceToken)
   , clsName :: Name (N.ProperName 'N.ClassName)
   , clsVars :: [TypeVarBinding a]
-  , clsFundeps :: Maybe (SourceToken, Separated ClassFundep)
+  , clsFundeps :: Maybe (SourceToken, SeparatedExtra ClassFundep)
   } deriving (Show, Eq, Ord, Functor, Foldable, Traversable, Generic)
 
 data ClassFundep