Support GHC up to 9.6 and add CI for them all (google#457)

* Minor changes for 9.6: imports and TypeOperators

Bump up some bounds on base which should make this a safe change
on older ghc versions.

* Use Language.Haskell.Syntax.Module.Name on 9.6

* Backward compatibility break: quote `forall`

GHC started warning about using `forall` as an identifier.  We might
as well quote it now and document in the release notes.

* Relax version bounds for 9.6

* Rework the CI

Reduce the matrix to versions to 9.{0,2,4,6}

* Temporarily use ghc-source-gen from hackage until it's in stackage

package.yaml

@@ -45,7 +45,7 @@ library:
     - primitive >= 0.6 && < 0.9
     - profunctors >= 5.2 && < 6.0
     - tagged == 0.8.*
-    - text >= 1.2 && < 2.1
+    - text >= 1.2 && < 2.2
     - transformers >= 0.4 && < 0.7
     - vector >= 0.11 && < 0.14
 

proto-lens.cabal

@@ -1,6 +1,6 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.35.2.
+-- This file has been generated from package.yaml by hpack version 0.36.0.
 --
 -- see: https://github.com/sol/hpack
 
@@ -69,7 +69,7 @@ library
     , primitive >=0.6 && <0.9
     , profunctors >=5.2 && <6.0
     , tagged ==0.8.*
-    , text >=1.2 && <2.1
+    , text >=1.2 && <2.2
     , transformers >=0.4 && <0.7
     , vector >=0.11 && <0.14
   default-language: Haskell2010

src/Data/ProtoLens/Labels.hs

@@ -3,6 +3,7 @@
 {-# LANGUAGE MagicHash #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE UndecidableInstances #-}
 #if __GLASGOW_HASKELL__ >= 802
 {-# LANGUAGE ScopedTypeVariables #-}

tests/parser_test.hs

@@ -1,7 +1,6 @@
 -- | Unit and property tests for our custom parsing monad.
 module Main (main) where
 
-import Control.Applicative (liftA2)
 import qualified Data.ByteString as B
 import Data.Either (isLeft)
 
@@ -74,7 +73,7 @@ testFailure =
 testIsolate :: [TestTree]
 testIsolate =
     [ testProperty "many" $ \bs bs' ->
-        runParser (liftA2 (,) (isolate (length bs) $ manyTillEnd getWord8)
+        runParser ((,) <$> (isolate (length bs) $ manyTillEnd getWord8) <*>
                         (manyTillEnd getWord8))
             (B.pack (bs ++ bs'))
             == Right (bs, bs')