From 7f16a3fd68a22ff34d938973f4d2bc793490c3d7 Mon Sep 17 00:00:00 2001
From: Mann mit Hut <github+mmhat@with-h.at>
Date: Thu, 3 Feb 2022 22:26:16 +0100
Subject: [PATCH] Fixed compilation with GHC 9.2

---
 effectful-th/src/Effectful/TH.hs | 19 +++++++++++--------
 effectful-th/tests/Fail.hs       |  2 ++
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/effectful-th/src/Effectful/TH.hs b/effectful-th/src/Effectful/TH.hs
index 31d29452..a5d97d60 100644
--- a/effectful-th/src/Effectful/TH.hs
+++ b/effectful-th/src/Effectful/TH.hs
@@ -75,7 +75,8 @@ makeSendFunctionFor tinfo cinfo = do
   let replaceEff = map (pure . replaceTV m effMonad)
 
   -- Create the function's type signature.
-  let bndrs = effectVarBndrs <> constructorVars cinfo <> [esBndr, rBndr]
+  let bndrs = map (mapTVFlag (const inferredSpec)) $
+        effectVarBndrs <> constructorVars cinfo <> [esBndr, rBndr]
 
   let effect = appsT $ conT (datatypeName tinfo) : map varT effectVars
       effectConstraint = [t| $(effect) :> $(varT es) |]
@@ -86,7 +87,7 @@ makeSendFunctionFor tinfo cinfo = do
       eff = [t| Eff $(varT es) $(varT r) |]
       funSig = arrowsT args eff
 
-  sig <- sigD fname $ forallT bndrs ctx funSig
+  sig <- withDoc $ sigD fname $ forallT bndrs ctx funSig
 
   -- Create the function's definition.
   ns <- let
@@ -101,14 +102,16 @@ makeSendFunctionFor tinfo cinfo = do
 
   defn <- funD fname [clause pats body []]
 
+  pure [sig, defn]
+  where
+    withDoc :: Q Dec -> Q Dec
 #if MIN_VERSION_template_haskell(2,18,0)
-  let doc :: String
-      doc = "-- | Send the '"
-        <> show (constructorName cinfo)
-        <> "' effect to the effect handler."
-  pure [withDecDoc doc sig, defn]
+    withDoc = withDecDoc
+      $  "-- | Send the '"
+      <> show (constructorName cinfo)
+      <> "' effect to the effect handler."
 #else
-  pure [sig, defn]
+    withDoc = id
 #endif
 
 toFunctionName :: Name -> Name
diff --git a/effectful-th/tests/Fail.hs b/effectful-th/tests/Fail.hs
index 6f0b3151..e2b6b3a5 100644
--- a/effectful-th/tests/Fail.hs
+++ b/effectful-th/tests/Fail.hs
@@ -1,6 +1,8 @@
 {-# LANGUAGE TemplateHaskell #-}
 module Fail where
 
+import Prelude hiding (fail)
+
 import Effectful.Fail (Fail)
 import Effectful.TH