From 3cfcfacd728fec948d72e04bfcd64bbf97979280 Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Thu, 12 Aug 2021 09:22:34 -0700
Subject: [PATCH] Use Prelude from base-compat for ghc 8.4 too.
We were having trouble building on ghc 8.4 because of
the lack of a Foldable instance for (Alt Maybe) in
base < 4.12.
Mystery: for some reason our builds were failing for gitit
but not in the pandoc CI.
---
pandoc.cabal | 2 +-
src/Text/Pandoc/Readers/Odt/ContentReader.hs | 6 +-----
2 files changed, 2 insertions(+), 6 deletions(-)
diff --git a/pandoc.cabal b/pandoc.cabal
index 81c3546e7..66ac50ce3 100644
--- a/pandoc.cabal
+++ b/pandoc.cabal
@@ -410,7 +410,7 @@ common common-options
-Wincomplete-record-updates
-Wnoncanonical-monad-instances
- if impl(ghc < 8.4)
+ if impl(ghc < 8.6)
hs-source-dirs: prelude
other-modules: Prelude
build-depends: base-compat >= 0.9
diff --git a/src/Text/Pandoc/Readers/Odt/ContentReader.hs b/src/Text/Pandoc/Readers/Odt/ContentReader.hs
index 734a6e116..5520d039f 100644
--- a/src/Text/Pandoc/Readers/Odt/ContentReader.hs
+++ b/src/Text/Pandoc/Readers/Odt/ContentReader.hs
@@ -7,9 +7,6 @@
{-# LANGUAGE TupleSections #-}
{-# LANGUAGE ViewPatterns #-}
{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE StandaloneDeriving #-}
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE FlexibleContexts #-}
{- |
Module : Text.Pandoc.Readers.Odt.ContentReader
Copyright : Copyright (C) 2015 Martin Linnemann
@@ -510,8 +507,7 @@ type InlineMatcher = ElementMatcher Inlines
type BlockMatcher = ElementMatcher Blocks
newtype FirstMatch a = FirstMatch (Alt Maybe a)
- deriving (Monoid, Semigroup)
-deriving instance Foldable FirstMatch
+ deriving (Foldable, Monoid, Semigroup)
firstMatch :: a -> FirstMatch a
firstMatch = FirstMatch . Alt . Just