Group StandaloneKindSignatures with type synonyms

CHANGELOG.md

@@ -1,3 +1,8 @@
+## Unreleased
+
+* Now standalone kind signatures are grouped with type synonyms. [Issue
+  683](https://github.com/tweag/ormolu/issues/683).
+
 ## Ormolu 0.1.4.1
 
 * Added command line option `--color` to control how diffs are printed.

data/examples/declaration/signature/standalone-kind-out.hs

@@ -11,3 +11,6 @@ class C1 a
 
 type F :: Type -> Type
 type family F
+
+type G :: Type
+type G = a

data/examples/declaration/signature/standalone-kind.hs

@@ -11,3 +11,7 @@ class C1 a
 
 type F :: Type -> Type
 type family F
+
+type G :: Type
+
+type G = a

ormolu.cabal

@@ -141,6 +141,9 @@ library
     else
         ghc-options: -O2 -Wall
 
+    if impl(ghc <8.10.0)
+        ghc-options: -fmax-pmcheck-iterations=3000000
+
 executable ormolu
     main-is:          Main.hs
     hs-source-dirs:   app

src/Ormolu/Printer/Meat/Declaration.hs

@@ -188,6 +188,7 @@ groupedDecls (L l_x x') (L l_y y') =
     (KindSignature n, DataDeclaration n') -> n == n'
     (KindSignature n, ClassDeclaration n') -> n == n'
     (KindSignature n, FamilyDeclaration n') -> n == n'
+    (KindSignature n, TypeSynonym n') -> n == n'
     -- Special case for TH splices, we look at locations
     (Splice, Splice) -> not (separatedByBlank id l_x l_y)
     -- This looks only at Haddocks, normal comments are handled elsewhere
@@ -247,7 +248,8 @@ pattern
   DataDeclaration,
   ClassDeclaration,
   KindSignature,
-  FamilyDeclaration ::
+  FamilyDeclaration,
+  TypeSynonym ::
     RdrName -> HsDecl GhcPs
 pattern InlinePragma n <- SigD NoExtField (InlineSig NoExtField (L _ n) _)
 pattern SpecializePragma n <- SigD NoExtField (SpecSig NoExtField (L _ n) _ _)
@@ -259,6 +261,7 @@ pattern DataDeclaration n <- TyClD NoExtField (DataDecl NoExtField (L _ n) _ _ _
 pattern ClassDeclaration n <- TyClD NoExtField (ClassDecl NoExtField _ (L _ n) _ _ _ _ _ _ _ _)
 pattern KindSignature n <- KindSigD NoExtField (StandaloneKindSig NoExtField (L _ n) _)
 pattern FamilyDeclaration n <- TyClD NoExtField (FamDecl NoExtField (FamilyDecl NoExtField _ (L _ n) _ _ _ _))
+pattern TypeSynonym n <- TyClD NoExtField (SynDecl NoExtField (L _ n) _ _ _)
 
 -- Declarations which can refer to multiple names