Fix build against semialign-1.3

.github/workflows/haskell-ci.yml

@@ -267,6 +267,12 @@ jobs:
       - name: prepare for constraint sets
         run: |
           rm -f cabal.project.local
+      - name: constraint set semialign-1.3
+        run: |
+          $CABAL v2-build $ARG_COMPILER --disable-tests --disable-benchmarks --constraint='semialign >=1.3 && <1.4' all --dry-run
+          cabal-plan topo | sort
+          $CABAL v2-build $ARG_COMPILER --disable-tests --disable-benchmarks --constraint='semialign >=1.3 && <1.4' --dependencies-only -j2 all
+          $CABAL v2-build $ARG_COMPILER --disable-tests --disable-benchmarks --constraint='semialign >=1.3 && <1.4' all
       - name: constraint set random-hashable
         run: |
           if [ $((HCNUMVER >= 90400 && HCNUMVER < 90600)) -ne 0 ] ; then $CABAL v2-build $ARG_COMPILER --enable-tests --disable-benchmarks --constraint='hashable >=1.3.2.0' --constraint='hashable +random-initial-seed' all --dry-run ; fi

ChangeLog.md

@@ -1,3 +1,7 @@
+## 0.4.1
+
+- Fix build with semialign-1.3
+
 ## 0.4
 
 - Drop `ansi-wl-pprint` dependency, use `prettyprinter` directly.

cabal.haskell-ci

@@ -13,3 +13,6 @@ constraint-set random-hashable
   constraints: hashable >=1.3.2.0, hashable +random-initial-seed
   tests: True
   run-tests: True
+
+constraint-set semialign-1.3
+  constraints: semialign >=1.3 && <1.4

src/Data/TreeDiff/OMap.hs

@@ -14,10 +14,12 @@ module Data.TreeDiff.OMap (
     elems,
 ) where
 
+import Prelude hiding (zipWith)
+
 import Control.DeepSeq (NFData (..))
 import Data.List       (sortBy)
 import Data.Ord        (comparing)
-import Data.Semialign  (Semialign(..), Unzip (..), unzipDefault)
+import Data.Semialign  (Semialign(..), Unzip (..), Zip (..), unzipDefault)
 import Data.These      (These (..))
 
 import qualified Data.Map.Strict as Map
@@ -149,5 +151,10 @@ instance Ord k => Semialign (OMap k) where
         g (That (Val j y))            = Val j (f (That y))
         g (These (Val i x) (Val j y)) = Val (min i j) (f (These x y))
 
-instance Unzip (OMap k) where
+instance Ord k => Zip (OMap k) where
+    zipWith f (OMap xs) (OMap ys) = OMap (zipWith g xs ys) where
+        g (Val i x) (Val j y) = Val (min i j) (f x y)
+
+-- Ord k is required for semialign <1.4
+instance Ord k => Unzip (OMap k) where
     unzip = unzipDefault

tree-diff.cabal

@@ -1,6 +1,6 @@
 cabal-version:      2.2
 name:               tree-diff
-version:            0.4
+version:            0.4.1
 synopsis:           Diffing of (expression) trees.
 category:           Data, Testing
 description: