From 760c52e04f0f1595e06d898e4d01d922bb3da2ae Mon Sep 17 00:00:00 2001
From: Patrick Thomson <patrickt@github.com>
Date: Tue, 14 Jan 2020 15:28:04 -0500
Subject: [PATCH] Clean up some instances

---
 semantic-python/src/Language/Python.hs        | 21 +++++++------------
 .../src/Convert/ToScopeGraph.hs               |  4 +++-
 2 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/semantic-python/src/Language/Python.hs b/semantic-python/src/Language/Python.hs
index d6c885e55..684816f2a 100644
--- a/semantic-python/src/Language/Python.hs
+++ b/semantic-python/src/Language/Python.hs
@@ -94,8 +94,7 @@ instance ToScopeGraph Py.DictionarySplat where scopeGraph = todo
 
 deriving instance ToScopeGraph Py.Expression
 
-instance ToScopeGraph Py.ElseClause where
-  scopeGraph (Py.ElseClause _ elc) = scopeGraph elc
+instance ToScopeGraph Py.ElseClause where scopeGraph = onField @"body"
 
 instance ToScopeGraph Py.ElifClause where
   scopeGraph (Py.ElifClause _ body condition) = mappend <$> scopeGraph condition <*> scopeGraph body
@@ -110,11 +109,9 @@ instance ToScopeGraph Py.ExpressionStatement where scopeGraph = onChildren
 
 instance ToScopeGraph Py.ExpressionList where scopeGraph = onChildren
 
-instance ToScopeGraph Py.False where
-  scopeGraph _ = pure mempty
+instance ToScopeGraph Py.False where scopeGraph _ = pure mempty
 
-instance ToScopeGraph Py.FinallyClause where
-  scopeGraph (Py.FinallyClause _ block) = scopeGraph block
+instance ToScopeGraph Py.FinallyClause where scopeGraph = onField @"extraChildren"
 
 instance ToScopeGraph Py.Float where scopeGraph = const (pure mempty)
 
@@ -167,14 +164,12 @@ instance ToScopeGraph Py.ReturnStatement where
 instance ToScopeGraph Py.True where
   scopeGraph _ = pure mempty
 
-instance ToScopeGraph Py.NotOperator where
-  scopeGraph (Py.NotOperator _ arg) = scopeGraph arg
+instance ToScopeGraph Py.NotOperator where scopeGraph = onField @"argument"
 
 instance ToScopeGraph Py.Pair where
   scopeGraph (Py.Pair _ value key) = mappend <$> scopeGraph key <*> scopeGraph value
 
-instance ToScopeGraph Py.ParenthesizedExpression where
-  scopeGraph (Py.ParenthesizedExpression _ e) = scopeGraph e
+instance ToScopeGraph Py.ParenthesizedExpression where scopeGraph = onField "extraChildren"
 
 instance ToScopeGraph Py.PassStatement where scopeGraph _ = pure mempty
 
@@ -185,8 +180,7 @@ deriving instance ToScopeGraph Py.PrimaryExpression
 
 deriving instance ToScopeGraph Py.SimpleStatement
 
-instance ToScopeGraph Py.RaiseStatement where
-  scopeGraph = todo
+instance ToScopeGraph Py.RaiseStatement where scopeGraph = todo
 
 instance ToScopeGraph Py.Set where scopeGraph = onChildren
 
@@ -204,8 +198,7 @@ instance ToScopeGraph Py.TryStatement where
     els <- traverse scopeGraph elseClauses
     pure (fold (NonEmpty.cons bod els))
 
-instance ToScopeGraph Py.UnaryOperator where
-  scopeGraph (Py.UnaryOperator _ _ arg) = scopeGraph arg
+instance ToScopeGraph Py.UnaryOperator where scopeGraph = onField @"argument"
 
 instance ToScopeGraph Py.WhileStatement where
   scopeGraph Py.WhileStatement{ alternative, body, condition } = do
diff --git a/semantic-scope-graph/src/Convert/ToScopeGraph.hs b/semantic-scope-graph/src/Convert/ToScopeGraph.hs
index 689a9eb3f..b7caaecbb 100644
--- a/semantic-scope-graph/src/Convert/ToScopeGraph.hs
+++ b/semantic-scope-graph/src/Convert/ToScopeGraph.hs
@@ -2,6 +2,7 @@
 {-# LANGUAGE DataKinds                 #-}
 {-# LANGUAGE ExistentialQuantification #-}
 {-# LANGUAGE FlexibleContexts          #-}
+{-# LANGUAGE KindSignatures            #-}
 {-# LANGUAGE ScopedTypeVariables       #-}
 {-# LANGUAGE TypeApplications          #-}
 {-# LANGUAGE TypeOperators             #-}
@@ -19,6 +20,7 @@ import Data.Name (Name)
 import Data.Typeable
 import GHC.Generics
 import GHC.Records
+import GHC.TypeLits
 import Source.Loc
 
 class Typeable t => ToScopeGraph t where
@@ -46,7 +48,7 @@ instance (ToScopeGraph l, ToScopeGraph r) => ToScopeGraph (l :+: r) where
   scopeGraph (R1 r) = scopeGraph r
 
 onField ::
-  forall field syn sig m r .
+  forall (field :: Symbol) syn sig m r .
   ( Has (Sketch Name) sig m
   , HasField field (r Loc) (syn Loc)
   , ToScopeGraph syn