diff --git a/.changeset/modern-tips-sell.md b/.changeset/modern-tips-sell.md
new file mode 100644
index 00000000..0debd380
--- /dev/null
+++ b/.changeset/modern-tips-sell.md
@@ -0,0 +1,5 @@
+---
+"@tsplus/stdlib": patch
+---
+
+add Differ data type
diff --git a/.eslintrc.cjs b/.eslintrc.cjs
index 11b8c02e..b87c6195 100644
--- a/.eslintrc.cjs
+++ b/.eslintrc.cjs
@@ -31,6 +31,7 @@ module.exports = {
           // The TypeScript configuration of dprint
           // See also https://dprint.dev/plugins/typescript/config/,
           "indentWidth": 2,
+          "lineWidth": 100,
           "semiColons": "asi",
           "quoteStyle": "alwaysDouble",
           "trailingCommas": "never",
diff --git a/package.json b/package.json
index 238b4bf9..d41613f6 100644
--- a/package.json
+++ b/package.json
@@ -35,12 +35,12 @@
     "@babel/core": "^7.18.10",
     "@babel/plugin-transform-modules-commonjs": "^7.18.6",
     "@changesets/changelog-github": "^0.4.6",
-    "@changesets/cli": "^2.24.1",
+    "@changesets/cli": "^2.24.2",
     "@effect-ts/build-utils": "0.40.3",
     "@effect-ts/core": "^0.60.2",
     "@repo-tooling/eslint-plugin-dprint": "^0.0.4",
     "@tsplus/installer": "0.0.132",
-    "@types/node": "^18.6.3",
+    "@types/node": "^18.6.4",
     "@types/rimraf": "^3.0.2",
     "@typescript-eslint/eslint-plugin": "^5.32.0",
     "@typescript-eslint/parser": "^5.32.0",
diff --git a/packages/stdlib/_src/collections/Chunk.ts b/packages/stdlib/_src/collections/Chunk.ts
index 2370fb94..54acb61d 100644
--- a/packages/stdlib/_src/collections/Chunk.ts
+++ b/packages/stdlib/_src/collections/Chunk.ts
@@ -1,103 +1,6 @@
 // codegen:start {preset: barrel, include: ./Chunk/*.ts, prefix: "@tsplus/stdlib/collections"}
-export * from "@tsplus/stdlib/collections/Chunk/append"
-export * from "@tsplus/stdlib/collections/Chunk/buckets"
-export * from "@tsplus/stdlib/collections/Chunk/builder"
-export * from "@tsplus/stdlib/collections/Chunk/collect"
-export * from "@tsplus/stdlib/collections/Chunk/collectWhile"
-export * from "@tsplus/stdlib/collections/Chunk/collectWithIndex"
-export * from "@tsplus/stdlib/collections/Chunk/compact"
-export * from "@tsplus/stdlib/collections/Chunk/compactF"
-export * from "@tsplus/stdlib/collections/Chunk/compactWithIndexF"
-export * from "@tsplus/stdlib/collections/Chunk/concat"
-export * from "@tsplus/stdlib/collections/Chunk/dedupe"
 export * from "@tsplus/stdlib/collections/Chunk/definition"
-export * from "@tsplus/stdlib/collections/Chunk/difference"
-export * from "@tsplus/stdlib/collections/Chunk/drop"
-export * from "@tsplus/stdlib/collections/Chunk/dropRight"
-export * from "@tsplus/stdlib/collections/Chunk/dropWhile"
-export * from "@tsplus/stdlib/collections/Chunk/elem"
-export * from "@tsplus/stdlib/collections/Chunk/empty"
-export * from "@tsplus/stdlib/collections/Chunk/equals"
-export * from "@tsplus/stdlib/collections/Chunk/exists"
-export * from "@tsplus/stdlib/collections/Chunk/extend"
-export * from "@tsplus/stdlib/collections/Chunk/fill"
-export * from "@tsplus/stdlib/collections/Chunk/filter"
-export * from "@tsplus/stdlib/collections/Chunk/filterWithIndex"
-export * from "@tsplus/stdlib/collections/Chunk/find"
-export * from "@tsplus/stdlib/collections/Chunk/findIndex"
-export * from "@tsplus/stdlib/collections/Chunk/findLast"
-export * from "@tsplus/stdlib/collections/Chunk/findLastIndex"
-export * from "@tsplus/stdlib/collections/Chunk/flatMap"
-export * from "@tsplus/stdlib/collections/Chunk/flatten"
-export * from "@tsplus/stdlib/collections/Chunk/forAll"
-export * from "@tsplus/stdlib/collections/Chunk/forAny"
-export * from "@tsplus/stdlib/collections/Chunk/forEach"
-export * from "@tsplus/stdlib/collections/Chunk/forEachF"
-export * from "@tsplus/stdlib/collections/Chunk/forEachWithIndexF"
-export * from "@tsplus/stdlib/collections/Chunk/get"
-export * from "@tsplus/stdlib/collections/Chunk/getAssociative"
-export * from "@tsplus/stdlib/collections/Chunk/getAssociativeIdentity"
-export * from "@tsplus/stdlib/collections/Chunk/getEquivalence"
-export * from "@tsplus/stdlib/collections/Chunk/getOrd"
-export * from "@tsplus/stdlib/collections/Chunk/getShow"
-export * from "@tsplus/stdlib/collections/Chunk/grouped"
-export * from "@tsplus/stdlib/collections/Chunk/head"
-export * from "@tsplus/stdlib/collections/Chunk/indexWhere"
-export * from "@tsplus/stdlib/collections/Chunk/indexWhereFrom"
 export * from "@tsplus/stdlib/collections/Chunk/instances"
-export * from "@tsplus/stdlib/collections/Chunk/intersection"
-export * from "@tsplus/stdlib/collections/Chunk/isEmpty"
-export * from "@tsplus/stdlib/collections/Chunk/isNonEmpty"
-export * from "@tsplus/stdlib/collections/Chunk/join"
-export * from "@tsplus/stdlib/collections/Chunk/last"
-export * from "@tsplus/stdlib/collections/Chunk/make"
-export * from "@tsplus/stdlib/collections/Chunk/makeBy"
-export * from "@tsplus/stdlib/collections/Chunk/map"
-export * from "@tsplus/stdlib/collections/Chunk/mapAccum"
-export * from "@tsplus/stdlib/collections/Chunk/mapWithIndex"
-export * from "@tsplus/stdlib/collections/Chunk/materialize"
-export * from "@tsplus/stdlib/collections/Chunk/partition"
-export * from "@tsplus/stdlib/collections/Chunk/partitionMap"
-export * from "@tsplus/stdlib/collections/Chunk/partitionMapWithIndex"
-export * from "@tsplus/stdlib/collections/Chunk/partitionWithIndex"
-export * from "@tsplus/stdlib/collections/Chunk/prepend"
-export * from "@tsplus/stdlib/collections/Chunk/range"
-export * from "@tsplus/stdlib/collections/Chunk/reduce"
-export * from "@tsplus/stdlib/collections/Chunk/reduceRight"
-export * from "@tsplus/stdlib/collections/Chunk/reduceRightWithIndex"
-export * from "@tsplus/stdlib/collections/Chunk/reduceWhile"
-export * from "@tsplus/stdlib/collections/Chunk/reduceWithIndex"
-export * from "@tsplus/stdlib/collections/Chunk/reverse"
-export * from "@tsplus/stdlib/collections/Chunk/reverseBuckets"
-export * from "@tsplus/stdlib/collections/Chunk/separate"
-export * from "@tsplus/stdlib/collections/Chunk/separateF"
-export * from "@tsplus/stdlib/collections/Chunk/separateWithIndexF"
-export * from "@tsplus/stdlib/collections/Chunk/single"
-export * from "@tsplus/stdlib/collections/Chunk/size"
-export * from "@tsplus/stdlib/collections/Chunk/sort"
-export * from "@tsplus/stdlib/collections/Chunk/sortBy"
-export * from "@tsplus/stdlib/collections/Chunk/split"
-export * from "@tsplus/stdlib/collections/Chunk/splitAt"
-export * from "@tsplus/stdlib/collections/Chunk/splitWhere"
-export * from "@tsplus/stdlib/collections/Chunk/tail"
-export * from "@tsplus/stdlib/collections/Chunk/take"
-export * from "@tsplus/stdlib/collections/Chunk/takeRight"
-export * from "@tsplus/stdlib/collections/Chunk/takeWhile"
-export * from "@tsplus/stdlib/collections/Chunk/toArrayLike"
-export * from "@tsplus/stdlib/collections/Chunk/toCollection"
-export * from "@tsplus/stdlib/collections/Chunk/unfold"
-export * from "@tsplus/stdlib/collections/Chunk/union"
-export * from "@tsplus/stdlib/collections/Chunk/uniq"
-export * from "@tsplus/stdlib/collections/Chunk/unit"
-export * from "@tsplus/stdlib/collections/Chunk/unsafeGet"
-export * from "@tsplus/stdlib/collections/Chunk/unsafeHead"
-export * from "@tsplus/stdlib/collections/Chunk/unsafeLast"
-export * from "@tsplus/stdlib/collections/Chunk/unsafeTail"
-export * from "@tsplus/stdlib/collections/Chunk/unzip"
-export * from "@tsplus/stdlib/collections/Chunk/zip"
-export * from "@tsplus/stdlib/collections/Chunk/zipAll"
-export * from "@tsplus/stdlib/collections/Chunk/zipAllWith"
-export * from "@tsplus/stdlib/collections/Chunk/zipWith"
-export * from "@tsplus/stdlib/collections/Chunk/zipWithIndex"
-export * from "@tsplus/stdlib/collections/Chunk/zipWithIndexOffset"
+export * from "@tsplus/stdlib/collections/Chunk/operations"
+export * from "@tsplus/stdlib/collections/Chunk/patch"
 // codegen:end
diff --git a/packages/stdlib/_src/collections/Chunk/operations.ts b/packages/stdlib/_src/collections/Chunk/operations.ts
new file mode 100644
index 00000000..ffcf7ed4
--- /dev/null
+++ b/packages/stdlib/_src/collections/Chunk/operations.ts
@@ -0,0 +1,101 @@
+// codegen:start {preset: barrel, include: ./operations/*.ts, prefix: "@tsplus/stdlib/collections/Chunk"}
+export * from "@tsplus/stdlib/collections/Chunk/operations/append"
+export * from "@tsplus/stdlib/collections/Chunk/operations/buckets"
+export * from "@tsplus/stdlib/collections/Chunk/operations/builder"
+export * from "@tsplus/stdlib/collections/Chunk/operations/collect"
+export * from "@tsplus/stdlib/collections/Chunk/operations/collectWhile"
+export * from "@tsplus/stdlib/collections/Chunk/operations/collectWithIndex"
+export * from "@tsplus/stdlib/collections/Chunk/operations/compact"
+export * from "@tsplus/stdlib/collections/Chunk/operations/compactF"
+export * from "@tsplus/stdlib/collections/Chunk/operations/compactWithIndexF"
+export * from "@tsplus/stdlib/collections/Chunk/operations/concat"
+export * from "@tsplus/stdlib/collections/Chunk/operations/dedupe"
+export * from "@tsplus/stdlib/collections/Chunk/operations/difference"
+export * from "@tsplus/stdlib/collections/Chunk/operations/drop"
+export * from "@tsplus/stdlib/collections/Chunk/operations/dropRight"
+export * from "@tsplus/stdlib/collections/Chunk/operations/dropWhile"
+export * from "@tsplus/stdlib/collections/Chunk/operations/elem"
+export * from "@tsplus/stdlib/collections/Chunk/operations/empty"
+export * from "@tsplus/stdlib/collections/Chunk/operations/equals"
+export * from "@tsplus/stdlib/collections/Chunk/operations/exists"
+export * from "@tsplus/stdlib/collections/Chunk/operations/extend"
+export * from "@tsplus/stdlib/collections/Chunk/operations/fill"
+export * from "@tsplus/stdlib/collections/Chunk/operations/filter"
+export * from "@tsplus/stdlib/collections/Chunk/operations/filterWithIndex"
+export * from "@tsplus/stdlib/collections/Chunk/operations/find"
+export * from "@tsplus/stdlib/collections/Chunk/operations/findIndex"
+export * from "@tsplus/stdlib/collections/Chunk/operations/findLast"
+export * from "@tsplus/stdlib/collections/Chunk/operations/findLastIndex"
+export * from "@tsplus/stdlib/collections/Chunk/operations/flatMap"
+export * from "@tsplus/stdlib/collections/Chunk/operations/flatten"
+export * from "@tsplus/stdlib/collections/Chunk/operations/forAll"
+export * from "@tsplus/stdlib/collections/Chunk/operations/forAny"
+export * from "@tsplus/stdlib/collections/Chunk/operations/forEach"
+export * from "@tsplus/stdlib/collections/Chunk/operations/forEachF"
+export * from "@tsplus/stdlib/collections/Chunk/operations/forEachWithIndexF"
+export * from "@tsplus/stdlib/collections/Chunk/operations/get"
+export * from "@tsplus/stdlib/collections/Chunk/operations/getAssociative"
+export * from "@tsplus/stdlib/collections/Chunk/operations/getAssociativeIdentity"
+export * from "@tsplus/stdlib/collections/Chunk/operations/getEquivalence"
+export * from "@tsplus/stdlib/collections/Chunk/operations/getOrd"
+export * from "@tsplus/stdlib/collections/Chunk/operations/getShow"
+export * from "@tsplus/stdlib/collections/Chunk/operations/grouped"
+export * from "@tsplus/stdlib/collections/Chunk/operations/head"
+export * from "@tsplus/stdlib/collections/Chunk/operations/indexWhere"
+export * from "@tsplus/stdlib/collections/Chunk/operations/indexWhereFrom"
+export * from "@tsplus/stdlib/collections/Chunk/operations/intersection"
+export * from "@tsplus/stdlib/collections/Chunk/operations/isEmpty"
+export * from "@tsplus/stdlib/collections/Chunk/operations/isNonEmpty"
+export * from "@tsplus/stdlib/collections/Chunk/operations/join"
+export * from "@tsplus/stdlib/collections/Chunk/operations/last"
+export * from "@tsplus/stdlib/collections/Chunk/operations/make"
+export * from "@tsplus/stdlib/collections/Chunk/operations/makeBy"
+export * from "@tsplus/stdlib/collections/Chunk/operations/map"
+export * from "@tsplus/stdlib/collections/Chunk/operations/mapAccum"
+export * from "@tsplus/stdlib/collections/Chunk/operations/mapWithIndex"
+export * from "@tsplus/stdlib/collections/Chunk/operations/materialize"
+export * from "@tsplus/stdlib/collections/Chunk/operations/partition"
+export * from "@tsplus/stdlib/collections/Chunk/operations/partitionMap"
+export * from "@tsplus/stdlib/collections/Chunk/operations/partitionMapWithIndex"
+export * from "@tsplus/stdlib/collections/Chunk/operations/partitionWithIndex"
+export * from "@tsplus/stdlib/collections/Chunk/operations/prepend"
+export * from "@tsplus/stdlib/collections/Chunk/operations/range"
+export * from "@tsplus/stdlib/collections/Chunk/operations/reduce"
+export * from "@tsplus/stdlib/collections/Chunk/operations/reduceRight"
+export * from "@tsplus/stdlib/collections/Chunk/operations/reduceRightWithIndex"
+export * from "@tsplus/stdlib/collections/Chunk/operations/reduceWhile"
+export * from "@tsplus/stdlib/collections/Chunk/operations/reduceWithIndex"
+export * from "@tsplus/stdlib/collections/Chunk/operations/reverse"
+export * from "@tsplus/stdlib/collections/Chunk/operations/reverseBuckets"
+export * from "@tsplus/stdlib/collections/Chunk/operations/separate"
+export * from "@tsplus/stdlib/collections/Chunk/operations/separateF"
+export * from "@tsplus/stdlib/collections/Chunk/operations/separateWithIndexF"
+export * from "@tsplus/stdlib/collections/Chunk/operations/single"
+export * from "@tsplus/stdlib/collections/Chunk/operations/size"
+export * from "@tsplus/stdlib/collections/Chunk/operations/sort"
+export * from "@tsplus/stdlib/collections/Chunk/operations/sortBy"
+export * from "@tsplus/stdlib/collections/Chunk/operations/split"
+export * from "@tsplus/stdlib/collections/Chunk/operations/splitAt"
+export * from "@tsplus/stdlib/collections/Chunk/operations/splitWhere"
+export * from "@tsplus/stdlib/collections/Chunk/operations/tail"
+export * from "@tsplus/stdlib/collections/Chunk/operations/take"
+export * from "@tsplus/stdlib/collections/Chunk/operations/takeRight"
+export * from "@tsplus/stdlib/collections/Chunk/operations/takeWhile"
+export * from "@tsplus/stdlib/collections/Chunk/operations/toArrayLike"
+export * from "@tsplus/stdlib/collections/Chunk/operations/toCollection"
+export * from "@tsplus/stdlib/collections/Chunk/operations/unfold"
+export * from "@tsplus/stdlib/collections/Chunk/operations/union"
+export * from "@tsplus/stdlib/collections/Chunk/operations/uniq"
+export * from "@tsplus/stdlib/collections/Chunk/operations/unit"
+export * from "@tsplus/stdlib/collections/Chunk/operations/unsafeGet"
+export * from "@tsplus/stdlib/collections/Chunk/operations/unsafeHead"
+export * from "@tsplus/stdlib/collections/Chunk/operations/unsafeLast"
+export * from "@tsplus/stdlib/collections/Chunk/operations/unsafeTail"
+export * from "@tsplus/stdlib/collections/Chunk/operations/unzip"
+export * from "@tsplus/stdlib/collections/Chunk/operations/zip"
+export * from "@tsplus/stdlib/collections/Chunk/operations/zipAll"
+export * from "@tsplus/stdlib/collections/Chunk/operations/zipAllWith"
+export * from "@tsplus/stdlib/collections/Chunk/operations/zipWith"
+export * from "@tsplus/stdlib/collections/Chunk/operations/zipWithIndex"
+export * from "@tsplus/stdlib/collections/Chunk/operations/zipWithIndexOffset"
+// codegen:end
diff --git a/packages/stdlib/_src/collections/Chunk/append.ts b/packages/stdlib/_src/collections/Chunk/operations/append.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/append.ts
rename to packages/stdlib/_src/collections/Chunk/operations/append.ts
diff --git a/packages/stdlib/_src/collections/Chunk/buckets.ts b/packages/stdlib/_src/collections/Chunk/operations/buckets.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/buckets.ts
rename to packages/stdlib/_src/collections/Chunk/operations/buckets.ts
diff --git a/packages/stdlib/_src/collections/Chunk/builder.ts b/packages/stdlib/_src/collections/Chunk/operations/builder.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/builder.ts
rename to packages/stdlib/_src/collections/Chunk/operations/builder.ts
diff --git a/packages/stdlib/_src/collections/Chunk/collect.ts b/packages/stdlib/_src/collections/Chunk/operations/collect.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/collect.ts
rename to packages/stdlib/_src/collections/Chunk/operations/collect.ts
diff --git a/packages/stdlib/_src/collections/Chunk/collectWhile.ts b/packages/stdlib/_src/collections/Chunk/operations/collectWhile.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/collectWhile.ts
rename to packages/stdlib/_src/collections/Chunk/operations/collectWhile.ts
diff --git a/packages/stdlib/_src/collections/Chunk/collectWithIndex.ts b/packages/stdlib/_src/collections/Chunk/operations/collectWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/collectWithIndex.ts
rename to packages/stdlib/_src/collections/Chunk/operations/collectWithIndex.ts
diff --git a/packages/stdlib/_src/collections/Chunk/compact.ts b/packages/stdlib/_src/collections/Chunk/operations/compact.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/compact.ts
rename to packages/stdlib/_src/collections/Chunk/operations/compact.ts
diff --git a/packages/stdlib/_src/collections/Chunk/compactF.ts b/packages/stdlib/_src/collections/Chunk/operations/compactF.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/compactF.ts
rename to packages/stdlib/_src/collections/Chunk/operations/compactF.ts
diff --git a/packages/stdlib/_src/collections/Chunk/compactWithIndexF.ts b/packages/stdlib/_src/collections/Chunk/operations/compactWithIndexF.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/compactWithIndexF.ts
rename to packages/stdlib/_src/collections/Chunk/operations/compactWithIndexF.ts
diff --git a/packages/stdlib/_src/collections/Chunk/concat.ts b/packages/stdlib/_src/collections/Chunk/operations/concat.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/concat.ts
rename to packages/stdlib/_src/collections/Chunk/operations/concat.ts
diff --git a/packages/stdlib/_src/collections/Chunk/dedupe.ts b/packages/stdlib/_src/collections/Chunk/operations/dedupe.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/dedupe.ts
rename to packages/stdlib/_src/collections/Chunk/operations/dedupe.ts
diff --git a/packages/stdlib/_src/collections/Chunk/difference.ts b/packages/stdlib/_src/collections/Chunk/operations/difference.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/difference.ts
rename to packages/stdlib/_src/collections/Chunk/operations/difference.ts
diff --git a/packages/stdlib/_src/collections/Chunk/drop.ts b/packages/stdlib/_src/collections/Chunk/operations/drop.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/drop.ts
rename to packages/stdlib/_src/collections/Chunk/operations/drop.ts
diff --git a/packages/stdlib/_src/collections/Chunk/dropRight.ts b/packages/stdlib/_src/collections/Chunk/operations/dropRight.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/dropRight.ts
rename to packages/stdlib/_src/collections/Chunk/operations/dropRight.ts
diff --git a/packages/stdlib/_src/collections/Chunk/dropWhile.ts b/packages/stdlib/_src/collections/Chunk/operations/dropWhile.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/dropWhile.ts
rename to packages/stdlib/_src/collections/Chunk/operations/dropWhile.ts
diff --git a/packages/stdlib/_src/collections/Chunk/elem.ts b/packages/stdlib/_src/collections/Chunk/operations/elem.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/elem.ts
rename to packages/stdlib/_src/collections/Chunk/operations/elem.ts
diff --git a/packages/stdlib/_src/collections/Chunk/empty.ts b/packages/stdlib/_src/collections/Chunk/operations/empty.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/empty.ts
rename to packages/stdlib/_src/collections/Chunk/operations/empty.ts
diff --git a/packages/stdlib/_src/collections/Chunk/equals.ts b/packages/stdlib/_src/collections/Chunk/operations/equals.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/equals.ts
rename to packages/stdlib/_src/collections/Chunk/operations/equals.ts
diff --git a/packages/stdlib/_src/collections/Chunk/exists.ts b/packages/stdlib/_src/collections/Chunk/operations/exists.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/exists.ts
rename to packages/stdlib/_src/collections/Chunk/operations/exists.ts
diff --git a/packages/stdlib/_src/collections/Chunk/extend.ts b/packages/stdlib/_src/collections/Chunk/operations/extend.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/extend.ts
rename to packages/stdlib/_src/collections/Chunk/operations/extend.ts
diff --git a/packages/stdlib/_src/collections/Chunk/fill.ts b/packages/stdlib/_src/collections/Chunk/operations/fill.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/fill.ts
rename to packages/stdlib/_src/collections/Chunk/operations/fill.ts
diff --git a/packages/stdlib/_src/collections/Chunk/filter.ts b/packages/stdlib/_src/collections/Chunk/operations/filter.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/filter.ts
rename to packages/stdlib/_src/collections/Chunk/operations/filter.ts
diff --git a/packages/stdlib/_src/collections/Chunk/filterWithIndex.ts b/packages/stdlib/_src/collections/Chunk/operations/filterWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/filterWithIndex.ts
rename to packages/stdlib/_src/collections/Chunk/operations/filterWithIndex.ts
diff --git a/packages/stdlib/_src/collections/Chunk/find.ts b/packages/stdlib/_src/collections/Chunk/operations/find.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/find.ts
rename to packages/stdlib/_src/collections/Chunk/operations/find.ts
diff --git a/packages/stdlib/_src/collections/Chunk/findIndex.ts b/packages/stdlib/_src/collections/Chunk/operations/findIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/findIndex.ts
rename to packages/stdlib/_src/collections/Chunk/operations/findIndex.ts
diff --git a/packages/stdlib/_src/collections/Chunk/findLast.ts b/packages/stdlib/_src/collections/Chunk/operations/findLast.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/findLast.ts
rename to packages/stdlib/_src/collections/Chunk/operations/findLast.ts
diff --git a/packages/stdlib/_src/collections/Chunk/findLastIndex.ts b/packages/stdlib/_src/collections/Chunk/operations/findLastIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/findLastIndex.ts
rename to packages/stdlib/_src/collections/Chunk/operations/findLastIndex.ts
diff --git a/packages/stdlib/_src/collections/Chunk/flatMap.ts b/packages/stdlib/_src/collections/Chunk/operations/flatMap.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/flatMap.ts
rename to packages/stdlib/_src/collections/Chunk/operations/flatMap.ts
diff --git a/packages/stdlib/_src/collections/Chunk/flatten.ts b/packages/stdlib/_src/collections/Chunk/operations/flatten.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/flatten.ts
rename to packages/stdlib/_src/collections/Chunk/operations/flatten.ts
diff --git a/packages/stdlib/_src/collections/Chunk/forAll.ts b/packages/stdlib/_src/collections/Chunk/operations/forAll.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/forAll.ts
rename to packages/stdlib/_src/collections/Chunk/operations/forAll.ts
diff --git a/packages/stdlib/_src/collections/Chunk/forAny.ts b/packages/stdlib/_src/collections/Chunk/operations/forAny.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/forAny.ts
rename to packages/stdlib/_src/collections/Chunk/operations/forAny.ts
diff --git a/packages/stdlib/_src/collections/Chunk/forEach.ts b/packages/stdlib/_src/collections/Chunk/operations/forEach.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/forEach.ts
rename to packages/stdlib/_src/collections/Chunk/operations/forEach.ts
diff --git a/packages/stdlib/_src/collections/Chunk/forEachF.ts b/packages/stdlib/_src/collections/Chunk/operations/forEachF.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/forEachF.ts
rename to packages/stdlib/_src/collections/Chunk/operations/forEachF.ts
diff --git a/packages/stdlib/_src/collections/Chunk/forEachWithIndexF.ts b/packages/stdlib/_src/collections/Chunk/operations/forEachWithIndexF.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/forEachWithIndexF.ts
rename to packages/stdlib/_src/collections/Chunk/operations/forEachWithIndexF.ts
diff --git a/packages/stdlib/_src/collections/Chunk/get.ts b/packages/stdlib/_src/collections/Chunk/operations/get.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/get.ts
rename to packages/stdlib/_src/collections/Chunk/operations/get.ts
diff --git a/packages/stdlib/_src/collections/Chunk/getAssociative.ts b/packages/stdlib/_src/collections/Chunk/operations/getAssociative.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/getAssociative.ts
rename to packages/stdlib/_src/collections/Chunk/operations/getAssociative.ts
diff --git a/packages/stdlib/_src/collections/Chunk/getAssociativeIdentity.ts b/packages/stdlib/_src/collections/Chunk/operations/getAssociativeIdentity.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/getAssociativeIdentity.ts
rename to packages/stdlib/_src/collections/Chunk/operations/getAssociativeIdentity.ts
diff --git a/packages/stdlib/_src/collections/Chunk/getEquivalence.ts b/packages/stdlib/_src/collections/Chunk/operations/getEquivalence.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/getEquivalence.ts
rename to packages/stdlib/_src/collections/Chunk/operations/getEquivalence.ts
diff --git a/packages/stdlib/_src/collections/Chunk/getOrd.ts b/packages/stdlib/_src/collections/Chunk/operations/getOrd.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/getOrd.ts
rename to packages/stdlib/_src/collections/Chunk/operations/getOrd.ts
diff --git a/packages/stdlib/_src/collections/Chunk/getShow.ts b/packages/stdlib/_src/collections/Chunk/operations/getShow.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/getShow.ts
rename to packages/stdlib/_src/collections/Chunk/operations/getShow.ts
diff --git a/packages/stdlib/_src/collections/Chunk/grouped.ts b/packages/stdlib/_src/collections/Chunk/operations/grouped.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/grouped.ts
rename to packages/stdlib/_src/collections/Chunk/operations/grouped.ts
diff --git a/packages/stdlib/_src/collections/Chunk/head.ts b/packages/stdlib/_src/collections/Chunk/operations/head.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/head.ts
rename to packages/stdlib/_src/collections/Chunk/operations/head.ts
diff --git a/packages/stdlib/_src/collections/Chunk/indexWhere.ts b/packages/stdlib/_src/collections/Chunk/operations/indexWhere.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/indexWhere.ts
rename to packages/stdlib/_src/collections/Chunk/operations/indexWhere.ts
diff --git a/packages/stdlib/_src/collections/Chunk/indexWhereFrom.ts b/packages/stdlib/_src/collections/Chunk/operations/indexWhereFrom.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/indexWhereFrom.ts
rename to packages/stdlib/_src/collections/Chunk/operations/indexWhereFrom.ts
diff --git a/packages/stdlib/_src/collections/Chunk/intersection.ts b/packages/stdlib/_src/collections/Chunk/operations/intersection.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/intersection.ts
rename to packages/stdlib/_src/collections/Chunk/operations/intersection.ts
diff --git a/packages/stdlib/_src/collections/Chunk/isEmpty.ts b/packages/stdlib/_src/collections/Chunk/operations/isEmpty.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/isEmpty.ts
rename to packages/stdlib/_src/collections/Chunk/operations/isEmpty.ts
diff --git a/packages/stdlib/_src/collections/Chunk/isNonEmpty.ts b/packages/stdlib/_src/collections/Chunk/operations/isNonEmpty.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/isNonEmpty.ts
rename to packages/stdlib/_src/collections/Chunk/operations/isNonEmpty.ts
diff --git a/packages/stdlib/_src/collections/Chunk/join.ts b/packages/stdlib/_src/collections/Chunk/operations/join.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/join.ts
rename to packages/stdlib/_src/collections/Chunk/operations/join.ts
diff --git a/packages/stdlib/_src/collections/Chunk/last.ts b/packages/stdlib/_src/collections/Chunk/operations/last.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/last.ts
rename to packages/stdlib/_src/collections/Chunk/operations/last.ts
diff --git a/packages/stdlib/_src/collections/Chunk/make.ts b/packages/stdlib/_src/collections/Chunk/operations/make.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/make.ts
rename to packages/stdlib/_src/collections/Chunk/operations/make.ts
diff --git a/packages/stdlib/_src/collections/Chunk/makeBy.ts b/packages/stdlib/_src/collections/Chunk/operations/makeBy.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/makeBy.ts
rename to packages/stdlib/_src/collections/Chunk/operations/makeBy.ts
diff --git a/packages/stdlib/_src/collections/Chunk/map.ts b/packages/stdlib/_src/collections/Chunk/operations/map.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/map.ts
rename to packages/stdlib/_src/collections/Chunk/operations/map.ts
diff --git a/packages/stdlib/_src/collections/Chunk/mapAccum.ts b/packages/stdlib/_src/collections/Chunk/operations/mapAccum.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/mapAccum.ts
rename to packages/stdlib/_src/collections/Chunk/operations/mapAccum.ts
diff --git a/packages/stdlib/_src/collections/Chunk/mapWithIndex.ts b/packages/stdlib/_src/collections/Chunk/operations/mapWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/mapWithIndex.ts
rename to packages/stdlib/_src/collections/Chunk/operations/mapWithIndex.ts
diff --git a/packages/stdlib/_src/collections/Chunk/materialize.ts b/packages/stdlib/_src/collections/Chunk/operations/materialize.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/materialize.ts
rename to packages/stdlib/_src/collections/Chunk/operations/materialize.ts
diff --git a/packages/stdlib/_src/collections/Chunk/partition.ts b/packages/stdlib/_src/collections/Chunk/operations/partition.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/partition.ts
rename to packages/stdlib/_src/collections/Chunk/operations/partition.ts
diff --git a/packages/stdlib/_src/collections/Chunk/partitionMap.ts b/packages/stdlib/_src/collections/Chunk/operations/partitionMap.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/partitionMap.ts
rename to packages/stdlib/_src/collections/Chunk/operations/partitionMap.ts
diff --git a/packages/stdlib/_src/collections/Chunk/partitionMapWithIndex.ts b/packages/stdlib/_src/collections/Chunk/operations/partitionMapWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/partitionMapWithIndex.ts
rename to packages/stdlib/_src/collections/Chunk/operations/partitionMapWithIndex.ts
diff --git a/packages/stdlib/_src/collections/Chunk/partitionWithIndex.ts b/packages/stdlib/_src/collections/Chunk/operations/partitionWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/partitionWithIndex.ts
rename to packages/stdlib/_src/collections/Chunk/operations/partitionWithIndex.ts
diff --git a/packages/stdlib/_src/collections/Chunk/prepend.ts b/packages/stdlib/_src/collections/Chunk/operations/prepend.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/prepend.ts
rename to packages/stdlib/_src/collections/Chunk/operations/prepend.ts
diff --git a/packages/stdlib/_src/collections/Chunk/range.ts b/packages/stdlib/_src/collections/Chunk/operations/range.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/range.ts
rename to packages/stdlib/_src/collections/Chunk/operations/range.ts
diff --git a/packages/stdlib/_src/collections/Chunk/reduce.ts b/packages/stdlib/_src/collections/Chunk/operations/reduce.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/reduce.ts
rename to packages/stdlib/_src/collections/Chunk/operations/reduce.ts
diff --git a/packages/stdlib/_src/collections/Chunk/reduceRight.ts b/packages/stdlib/_src/collections/Chunk/operations/reduceRight.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/reduceRight.ts
rename to packages/stdlib/_src/collections/Chunk/operations/reduceRight.ts
diff --git a/packages/stdlib/_src/collections/Chunk/reduceRightWithIndex.ts b/packages/stdlib/_src/collections/Chunk/operations/reduceRightWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/reduceRightWithIndex.ts
rename to packages/stdlib/_src/collections/Chunk/operations/reduceRightWithIndex.ts
diff --git a/packages/stdlib/_src/collections/Chunk/reduceWhile.ts b/packages/stdlib/_src/collections/Chunk/operations/reduceWhile.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/reduceWhile.ts
rename to packages/stdlib/_src/collections/Chunk/operations/reduceWhile.ts
diff --git a/packages/stdlib/_src/collections/Chunk/reduceWithIndex.ts b/packages/stdlib/_src/collections/Chunk/operations/reduceWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/reduceWithIndex.ts
rename to packages/stdlib/_src/collections/Chunk/operations/reduceWithIndex.ts
diff --git a/packages/stdlib/_src/collections/Chunk/reverse.ts b/packages/stdlib/_src/collections/Chunk/operations/reverse.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/reverse.ts
rename to packages/stdlib/_src/collections/Chunk/operations/reverse.ts
diff --git a/packages/stdlib/_src/collections/Chunk/reverseBuckets.ts b/packages/stdlib/_src/collections/Chunk/operations/reverseBuckets.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/reverseBuckets.ts
rename to packages/stdlib/_src/collections/Chunk/operations/reverseBuckets.ts
diff --git a/packages/stdlib/_src/collections/Chunk/separate.ts b/packages/stdlib/_src/collections/Chunk/operations/separate.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/separate.ts
rename to packages/stdlib/_src/collections/Chunk/operations/separate.ts
diff --git a/packages/stdlib/_src/collections/Chunk/separateF.ts b/packages/stdlib/_src/collections/Chunk/operations/separateF.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/separateF.ts
rename to packages/stdlib/_src/collections/Chunk/operations/separateF.ts
diff --git a/packages/stdlib/_src/collections/Chunk/separateWithIndexF.ts b/packages/stdlib/_src/collections/Chunk/operations/separateWithIndexF.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/separateWithIndexF.ts
rename to packages/stdlib/_src/collections/Chunk/operations/separateWithIndexF.ts
diff --git a/packages/stdlib/_src/collections/Chunk/single.ts b/packages/stdlib/_src/collections/Chunk/operations/single.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/single.ts
rename to packages/stdlib/_src/collections/Chunk/operations/single.ts
diff --git a/packages/stdlib/_src/collections/Chunk/size.ts b/packages/stdlib/_src/collections/Chunk/operations/size.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/size.ts
rename to packages/stdlib/_src/collections/Chunk/operations/size.ts
diff --git a/packages/stdlib/_src/collections/Chunk/sort.ts b/packages/stdlib/_src/collections/Chunk/operations/sort.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/sort.ts
rename to packages/stdlib/_src/collections/Chunk/operations/sort.ts
diff --git a/packages/stdlib/_src/collections/Chunk/sortBy.ts b/packages/stdlib/_src/collections/Chunk/operations/sortBy.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/sortBy.ts
rename to packages/stdlib/_src/collections/Chunk/operations/sortBy.ts
diff --git a/packages/stdlib/_src/collections/Chunk/split.ts b/packages/stdlib/_src/collections/Chunk/operations/split.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/split.ts
rename to packages/stdlib/_src/collections/Chunk/operations/split.ts
diff --git a/packages/stdlib/_src/collections/Chunk/splitAt.ts b/packages/stdlib/_src/collections/Chunk/operations/splitAt.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/splitAt.ts
rename to packages/stdlib/_src/collections/Chunk/operations/splitAt.ts
diff --git a/packages/stdlib/_src/collections/Chunk/splitWhere.ts b/packages/stdlib/_src/collections/Chunk/operations/splitWhere.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/splitWhere.ts
rename to packages/stdlib/_src/collections/Chunk/operations/splitWhere.ts
diff --git a/packages/stdlib/_src/collections/Chunk/tail.ts b/packages/stdlib/_src/collections/Chunk/operations/tail.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/tail.ts
rename to packages/stdlib/_src/collections/Chunk/operations/tail.ts
diff --git a/packages/stdlib/_src/collections/Chunk/take.ts b/packages/stdlib/_src/collections/Chunk/operations/take.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/take.ts
rename to packages/stdlib/_src/collections/Chunk/operations/take.ts
diff --git a/packages/stdlib/_src/collections/Chunk/takeRight.ts b/packages/stdlib/_src/collections/Chunk/operations/takeRight.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/takeRight.ts
rename to packages/stdlib/_src/collections/Chunk/operations/takeRight.ts
diff --git a/packages/stdlib/_src/collections/Chunk/takeWhile.ts b/packages/stdlib/_src/collections/Chunk/operations/takeWhile.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/takeWhile.ts
rename to packages/stdlib/_src/collections/Chunk/operations/takeWhile.ts
diff --git a/packages/stdlib/_src/collections/Chunk/toArrayLike.ts b/packages/stdlib/_src/collections/Chunk/operations/toArrayLike.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/toArrayLike.ts
rename to packages/stdlib/_src/collections/Chunk/operations/toArrayLike.ts
diff --git a/packages/stdlib/_src/collections/Chunk/toCollection.ts b/packages/stdlib/_src/collections/Chunk/operations/toCollection.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/toCollection.ts
rename to packages/stdlib/_src/collections/Chunk/operations/toCollection.ts
diff --git a/packages/stdlib/_src/collections/Chunk/unfold.ts b/packages/stdlib/_src/collections/Chunk/operations/unfold.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/unfold.ts
rename to packages/stdlib/_src/collections/Chunk/operations/unfold.ts
diff --git a/packages/stdlib/_src/collections/Chunk/union.ts b/packages/stdlib/_src/collections/Chunk/operations/union.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/union.ts
rename to packages/stdlib/_src/collections/Chunk/operations/union.ts
diff --git a/packages/stdlib/_src/collections/Chunk/uniq.ts b/packages/stdlib/_src/collections/Chunk/operations/uniq.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/uniq.ts
rename to packages/stdlib/_src/collections/Chunk/operations/uniq.ts
diff --git a/packages/stdlib/_src/collections/Chunk/unit.ts b/packages/stdlib/_src/collections/Chunk/operations/unit.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/unit.ts
rename to packages/stdlib/_src/collections/Chunk/operations/unit.ts
diff --git a/packages/stdlib/_src/collections/Chunk/unsafeGet.ts b/packages/stdlib/_src/collections/Chunk/operations/unsafeGet.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/unsafeGet.ts
rename to packages/stdlib/_src/collections/Chunk/operations/unsafeGet.ts
diff --git a/packages/stdlib/_src/collections/Chunk/unsafeHead.ts b/packages/stdlib/_src/collections/Chunk/operations/unsafeHead.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/unsafeHead.ts
rename to packages/stdlib/_src/collections/Chunk/operations/unsafeHead.ts
diff --git a/packages/stdlib/_src/collections/Chunk/unsafeLast.ts b/packages/stdlib/_src/collections/Chunk/operations/unsafeLast.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/unsafeLast.ts
rename to packages/stdlib/_src/collections/Chunk/operations/unsafeLast.ts
diff --git a/packages/stdlib/_src/collections/Chunk/unsafeTail.ts b/packages/stdlib/_src/collections/Chunk/operations/unsafeTail.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/unsafeTail.ts
rename to packages/stdlib/_src/collections/Chunk/operations/unsafeTail.ts
diff --git a/packages/stdlib/_src/collections/Chunk/unzip.ts b/packages/stdlib/_src/collections/Chunk/operations/unzip.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/unzip.ts
rename to packages/stdlib/_src/collections/Chunk/operations/unzip.ts
diff --git a/packages/stdlib/_src/collections/Chunk/zip.ts b/packages/stdlib/_src/collections/Chunk/operations/zip.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/zip.ts
rename to packages/stdlib/_src/collections/Chunk/operations/zip.ts
diff --git a/packages/stdlib/_src/collections/Chunk/zipAll.ts b/packages/stdlib/_src/collections/Chunk/operations/zipAll.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/zipAll.ts
rename to packages/stdlib/_src/collections/Chunk/operations/zipAll.ts
diff --git a/packages/stdlib/_src/collections/Chunk/zipAllWith.ts b/packages/stdlib/_src/collections/Chunk/operations/zipAllWith.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/zipAllWith.ts
rename to packages/stdlib/_src/collections/Chunk/operations/zipAllWith.ts
diff --git a/packages/stdlib/_src/collections/Chunk/zipWith.ts b/packages/stdlib/_src/collections/Chunk/operations/zipWith.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/zipWith.ts
rename to packages/stdlib/_src/collections/Chunk/operations/zipWith.ts
diff --git a/packages/stdlib/_src/collections/Chunk/zipWithIndex.ts b/packages/stdlib/_src/collections/Chunk/operations/zipWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/zipWithIndex.ts
rename to packages/stdlib/_src/collections/Chunk/operations/zipWithIndex.ts
diff --git a/packages/stdlib/_src/collections/Chunk/zipWithIndexOffset.ts b/packages/stdlib/_src/collections/Chunk/operations/zipWithIndexOffset.ts
similarity index 100%
rename from packages/stdlib/_src/collections/Chunk/zipWithIndexOffset.ts
rename to packages/stdlib/_src/collections/Chunk/operations/zipWithIndexOffset.ts
diff --git a/packages/stdlib/_src/collections/Chunk/patch.ts b/packages/stdlib/_src/collections/Chunk/patch.ts
new file mode 100644
index 00000000..f251023b
--- /dev/null
+++ b/packages/stdlib/_src/collections/Chunk/patch.ts
@@ -0,0 +1,4 @@
+// codegen:start {preset: barrel, include: ./patch/*.ts, prefix: "@tsplus/stdlib/collections/Chunk"}
+export * from "@tsplus/stdlib/collections/Chunk/patch/definition"
+export * from "@tsplus/stdlib/collections/Chunk/patch/operations"
+// codegen:end
diff --git a/packages/stdlib/_src/collections/Chunk/patch/definition.ts b/packages/stdlib/_src/collections/Chunk/patch/definition.ts
new file mode 100644
index 00000000..62fe5ce8
--- /dev/null
+++ b/packages/stdlib/_src/collections/Chunk/patch/definition.ts
@@ -0,0 +1,102 @@
+export const ChunkPatchSym = Symbol.for("@Differ.Chunk.Patch")
+export type ChunkPatchSym = typeof ChunkPatchSym
+
+export const ChunkPatchValueSym = Symbol.for("@Differ.Chunk.Patch.Value")
+export type ChunkPatchValueSym = typeof ChunkPatchValueSym
+
+export const ChunkPatchPatchSym = Symbol.for("@Differ.Chunk.Patch.Patch")
+export type ChunkPatchPatchSym = typeof ChunkPatchPatchSym
+
+/**
+ * A patch which describes updates to a chunk of values.
+ *
+ * @tsplus type Differ.Chunk.Patch
+ */
+export interface ChunkPatch<in out Value, in out Patch> {
+  readonly [ChunkPatchSym]: ChunkPatchSym
+  readonly [ChunkPatchValueSym]: (_: Value) => Value
+  readonly [ChunkPatchPatchSym]: (_: Patch) => Patch
+}
+
+/**
+ * @tsplus type Differ.Chunk.Patch.Ops
+ */
+export interface ChunkPatchOps {
+  readonly $: ChunkPatchAspects
+}
+/**
+ * @tsplus static Differ.Ops Chunk
+ */
+export const ChunkPatch: ChunkPatchOps = {
+  $: {}
+}
+
+/**
+ * @tsplus type Differ.Chunk.Patch.Aspects
+ */
+export interface ChunkPatchAspects {}
+
+/**
+ * @tsplus unify Differ.Chunk.Patch
+ */
+export function unifyChunkPatch<X extends ChunkPatch<any, any>>(self: X): ChunkPatch<
+  [X] extends [{ [ChunkPatchValueSym]: (_: infer Value) => infer Value }] ? Value : never,
+  [X] extends [{ [ChunkPatchPatchSym]: (_: infer Patch) => infer Patch }] ? Patch : never
+> {
+  return self
+}
+
+export abstract class BaseChunkPatch<Value, Patch> implements ChunkPatch<Value, Patch> {
+  readonly [ChunkPatchSym]: ChunkPatchSym = ChunkPatchSym
+  readonly [ChunkPatchValueSym]!: (_: Value) => Value
+  readonly [ChunkPatchPatchSym]!: (_: Patch) => Patch
+}
+
+export class AppendChunkPatch<Value, Patch> extends BaseChunkPatch<Value, Patch> {
+  readonly _tag = "Append"
+  constructor(readonly values: Chunk<Value>) {
+    super()
+  }
+}
+
+export class SliceChunkPatch<Value, Patch> extends BaseChunkPatch<Value, Patch> {
+  readonly _tag = "Slice"
+  constructor(readonly from: number, readonly until: number) {
+    super()
+  }
+}
+
+export class UpdateChunkPatch<Value, Patch> extends BaseChunkPatch<Value, Patch> {
+  readonly _tag = "Update"
+  constructor(readonly index: number, readonly patch: Patch) {
+    super()
+  }
+}
+
+export class AndThenChunkPatch<Value, Patch> extends BaseChunkPatch<Value, Patch> {
+  readonly _tag = "AndThen"
+  constructor(readonly first: ChunkPatch<Value, Patch>, readonly second: ChunkPatch<Value, Patch>) {
+    super()
+  }
+}
+
+export class EmptyChunkPatch<Value, Patch> extends BaseChunkPatch<Value, Patch> {
+  readonly _tag = "Empty"
+}
+
+export type ChunkPatchInstruction =
+  | AppendChunkPatch<any, any>
+  | SliceChunkPatch<any, any>
+  | UpdateChunkPatch<any, any>
+  | AndThenChunkPatch<any, any>
+  | EmptyChunkPatch<any, any>
+
+/**
+ * @tsplus macro identity
+ */
+export function chunkPatchInstruction<Value, Patch>(
+  self: ChunkPatch<Value, Patch>
+): ChunkPatchInstruction {
+  // @ts-expect-error
+  return self
+}
diff --git a/packages/stdlib/_src/collections/Chunk/patch/operations.ts b/packages/stdlib/_src/collections/Chunk/patch/operations.ts
new file mode 100644
index 00000000..636ea689
--- /dev/null
+++ b/packages/stdlib/_src/collections/Chunk/patch/operations.ts
@@ -0,0 +1,6 @@
+// codegen:start {preset: barrel, include: ./operations/*.ts, prefix: "@tsplus/stdlib/collections/Chunk/patch"}
+export * from "@tsplus/stdlib/collections/Chunk/patch/operations/apply"
+export * from "@tsplus/stdlib/collections/Chunk/patch/operations/combine"
+export * from "@tsplus/stdlib/collections/Chunk/patch/operations/diff"
+export * from "@tsplus/stdlib/collections/Chunk/patch/operations/emptyPatch"
+// codegen:end
diff --git a/packages/stdlib/_src/collections/Chunk/patch/operations/apply.ts b/packages/stdlib/_src/collections/Chunk/patch/operations/apply.ts
new file mode 100644
index 00000000..49cd03d3
--- /dev/null
+++ b/packages/stdlib/_src/collections/Chunk/patch/operations/apply.ts
@@ -0,0 +1,52 @@
+import { chunkPatchInstruction } from "@tsplus/stdlib/collections/Chunk/patch/definition"
+
+/**
+ * Applies a chunk patch to a chunk of values to produce a new chunk of
+ * values which represents the original chunk of values updated with the
+ * changes described by this patch.
+ *
+ * @tsplus static Differ.Chunk.Patch.Aspects apply
+ * @tsplus pipeable Differ.Chunk.Patch apply
+ */
+export function apply<Value, Patch>(oldValue: Chunk<Value>, differ: Differ<Value, Patch>) {
+  return (self: Differ.Chunk.Patch<Value, Patch>): Chunk<Value> =>
+    applyLoop(differ, oldValue, List(self))
+}
+
+/**
+ * @tsplus tailRec
+ */
+function applyLoop<Value, Patch>(
+  differ: Differ<Value, Patch>,
+  chunk: Chunk<Value>,
+  patches: List<Differ.Chunk.Patch<Value, Patch>>
+): Chunk<Value> {
+  if (patches.isNil()) {
+    return chunk
+  }
+  const patch = chunkPatchInstruction(patches.head)
+  const nextPatches = patches.tail
+  switch (patch._tag) {
+    case "Append": {
+      return applyLoop(differ, chunk.concat(patch.values), nextPatches)
+    }
+    case "AndThen": {
+      return applyLoop(differ, chunk, nextPatches.prepend(patch.second).prepend(patch.first))
+    }
+    case "Empty": {
+      return applyLoop(differ, chunk, nextPatches)
+    }
+    case "Slice": {
+      return applyLoop(
+        differ,
+        Chunk.from(chunk.toArray.slice(patch.from, patch.until)),
+        nextPatches
+      )
+    }
+    case "Update": {
+      const array = chunk.toArray
+      array[patch.index] = differ.patch(patch.patch, array[patch.index]!)
+      return applyLoop(differ, Chunk.from(array), nextPatches)
+    }
+  }
+}
diff --git a/packages/stdlib/_src/collections/Chunk/patch/operations/combine.ts b/packages/stdlib/_src/collections/Chunk/patch/operations/combine.ts
new file mode 100644
index 00000000..7b90527c
--- /dev/null
+++ b/packages/stdlib/_src/collections/Chunk/patch/operations/combine.ts
@@ -0,0 +1,13 @@
+import { AndThenChunkPatch } from "@tsplus/stdlib/collections/Chunk/patch/definition"
+
+/**
+ * Combines two chunk patches to produce a new chunk patch that describes
+ * applying their changes sequentially.
+ *
+ * @tsplus static Differ.Chunk.Patch.Aspects combine
+ * @tsplus pipeable Differ.Chunk.Patch combine
+ */
+export function combine<Value, Patch>(that: Differ.Chunk.Patch<Value, Patch>) {
+  return (self: Differ.Chunk.Patch<Value, Patch>): Differ.Chunk.Patch<Value, Patch> =>
+    new AndThenChunkPatch(self, that)
+}
diff --git a/packages/stdlib/_src/collections/Chunk/patch/operations/diff.ts b/packages/stdlib/_src/collections/Chunk/patch/operations/diff.ts
new file mode 100644
index 00000000..77cafba6
--- /dev/null
+++ b/packages/stdlib/_src/collections/Chunk/patch/operations/diff.ts
@@ -0,0 +1,36 @@
+import {
+  AppendChunkPatch,
+  SliceChunkPatch,
+  UpdateChunkPatch
+} from "@tsplus/stdlib/collections/Chunk/patch/definition"
+
+/**
+ * Constructs a chunk patch from a new and old chunk of values and a differ
+ * for the values.
+ *
+ * @tsplus static Differ.Chunk.Patch.Ops diff
+ */
+export function diff<Value, Patch>(
+  oldValue: Chunk<Value>,
+  newValue: Chunk<Value>,
+  differ: Differ<Value, Patch>
+): Differ.Chunk.Patch<Value, Patch> {
+  let i = 0
+  let patch = Differ.Chunk.empty<Value, Patch>()
+  while (i < oldValue.length && i < newValue.length) {
+    const oldElement = oldValue.unsafeGet(i)
+    const newElement = newValue.unsafeGet(i)
+    const valuePatch = differ.diff(oldElement, newElement)
+    if (!Equals.equals(valuePatch, differ.empty)) {
+      patch = patch.combine(new UpdateChunkPatch(i, valuePatch))
+    }
+    i = i + 1
+  }
+  if (i < oldValue.length) {
+    patch = patch.combine(new SliceChunkPatch(0, i))
+  }
+  if (i < newValue.length) {
+    patch = patch.combine(new AppendChunkPatch(newValue.drop(i)))
+  }
+  return patch
+}
diff --git a/packages/stdlib/_src/collections/Chunk/patch/operations/emptyPatch.ts b/packages/stdlib/_src/collections/Chunk/patch/operations/emptyPatch.ts
new file mode 100644
index 00000000..a98e297c
--- /dev/null
+++ b/packages/stdlib/_src/collections/Chunk/patch/operations/emptyPatch.ts
@@ -0,0 +1,10 @@
+import { EmptyChunkPatch } from "@tsplus/stdlib/collections/Chunk/patch/definition"
+
+/**
+ * Constructs an empty chunk patch.
+ *
+ * @tsplus static Differ.Chunk.Patch.Ops empty
+ */
+export function emptyPatch<Value, Patch>(): Differ.Chunk.Patch<Value, Patch> {
+  return new EmptyChunkPatch()
+}
diff --git a/packages/stdlib/_src/collections/HashMap.ts b/packages/stdlib/_src/collections/HashMap.ts
index b1bfe6a2..044cd276 100644
--- a/packages/stdlib/_src/collections/HashMap.ts
+++ b/packages/stdlib/_src/collections/HashMap.ts
@@ -1,43 +1,14 @@
-export { equals, equals_, getHash, getHash_, has, has_ } from "@tsplus/stdlib/collections/HashMap/_internal/hashMap"
+export {
+  equals,
+  equals_,
+  getHash,
+  getHash_,
+  has,
+  has_
+} from "@tsplus/stdlib/collections/HashMap/_internal/hashMap"
 
 // codegen:start {preset: barrel, include: ./HashMap/*.ts, prefix: "@tsplus/stdlib/collections"}
-export * from "@tsplus/stdlib/collections/HashMap/beginMutation"
-export * from "@tsplus/stdlib/collections/HashMap/collect"
-export * from "@tsplus/stdlib/collections/HashMap/collectWithIndex"
-export * from "@tsplus/stdlib/collections/HashMap/compact"
 export * from "@tsplus/stdlib/collections/HashMap/definition"
-export * from "@tsplus/stdlib/collections/HashMap/empty"
-export * from "@tsplus/stdlib/collections/HashMap/endMutation"
-export * from "@tsplus/stdlib/collections/HashMap/filter"
-export * from "@tsplus/stdlib/collections/HashMap/filterWithIndex"
-export * from "@tsplus/stdlib/collections/HashMap/flatMap"
-export * from "@tsplus/stdlib/collections/HashMap/flatMapWithIndex"
-export * from "@tsplus/stdlib/collections/HashMap/forEach"
-export * from "@tsplus/stdlib/collections/HashMap/forEachWithIndex"
-export * from "@tsplus/stdlib/collections/HashMap/from"
-export * from "@tsplus/stdlib/collections/HashMap/get"
-export * from "@tsplus/stdlib/collections/HashMap/getAssociative"
-export * from "@tsplus/stdlib/collections/HashMap/hasHash"
-export * from "@tsplus/stdlib/collections/HashMap/isEmpty"
-export * from "@tsplus/stdlib/collections/HashMap/keys"
-export * from "@tsplus/stdlib/collections/HashMap/keySet"
-export * from "@tsplus/stdlib/collections/HashMap/make"
-export * from "@tsplus/stdlib/collections/HashMap/map"
-export * from "@tsplus/stdlib/collections/HashMap/mapWithIndex"
-export * from "@tsplus/stdlib/collections/HashMap/modify"
-export * from "@tsplus/stdlib/collections/HashMap/modifyHash"
-export * from "@tsplus/stdlib/collections/HashMap/mutate"
-export * from "@tsplus/stdlib/collections/HashMap/node"
-export * from "@tsplus/stdlib/collections/HashMap/reduce"
-export * from "@tsplus/stdlib/collections/HashMap/reduceWithIndex"
-export * from "@tsplus/stdlib/collections/HashMap/remove"
-export * from "@tsplus/stdlib/collections/HashMap/removeMany"
-export * from "@tsplus/stdlib/collections/HashMap/set"
-export * from "@tsplus/stdlib/collections/HashMap/setTree"
-export * from "@tsplus/stdlib/collections/HashMap/size"
-export * from "@tsplus/stdlib/collections/HashMap/toCollection"
-export * from "@tsplus/stdlib/collections/HashMap/union"
-export * from "@tsplus/stdlib/collections/HashMap/unsafeGet"
-export * from "@tsplus/stdlib/collections/HashMap/update"
-export * from "@tsplus/stdlib/collections/HashMap/values"
+export * from "@tsplus/stdlib/collections/HashMap/operations"
+export * from "@tsplus/stdlib/collections/HashMap/patch"
 // codegen:end
diff --git a/packages/stdlib/_src/collections/HashMap/operations.ts b/packages/stdlib/_src/collections/HashMap/operations.ts
new file mode 100644
index 00000000..9d3ce388
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashMap/operations.ts
@@ -0,0 +1,40 @@
+// codegen:start {preset: barrel, include: ./operations/*.ts, prefix: "@tsplus/stdlib/collections/HashMap"}
+export * from "@tsplus/stdlib/collections/HashMap/operations/beginMutation"
+export * from "@tsplus/stdlib/collections/HashMap/operations/collect"
+export * from "@tsplus/stdlib/collections/HashMap/operations/collectWithIndex"
+export * from "@tsplus/stdlib/collections/HashMap/operations/compact"
+export * from "@tsplus/stdlib/collections/HashMap/operations/empty"
+export * from "@tsplus/stdlib/collections/HashMap/operations/endMutation"
+export * from "@tsplus/stdlib/collections/HashMap/operations/filter"
+export * from "@tsplus/stdlib/collections/HashMap/operations/filterWithIndex"
+export * from "@tsplus/stdlib/collections/HashMap/operations/flatMap"
+export * from "@tsplus/stdlib/collections/HashMap/operations/flatMapWithIndex"
+export * from "@tsplus/stdlib/collections/HashMap/operations/forEach"
+export * from "@tsplus/stdlib/collections/HashMap/operations/forEachWithIndex"
+export * from "@tsplus/stdlib/collections/HashMap/operations/from"
+export * from "@tsplus/stdlib/collections/HashMap/operations/get"
+export * from "@tsplus/stdlib/collections/HashMap/operations/getAssociative"
+export * from "@tsplus/stdlib/collections/HashMap/operations/hasHash"
+export * from "@tsplus/stdlib/collections/HashMap/operations/isEmpty"
+export * from "@tsplus/stdlib/collections/HashMap/operations/keys"
+export * from "@tsplus/stdlib/collections/HashMap/operations/keySet"
+export * from "@tsplus/stdlib/collections/HashMap/operations/make"
+export * from "@tsplus/stdlib/collections/HashMap/operations/map"
+export * from "@tsplus/stdlib/collections/HashMap/operations/mapWithIndex"
+export * from "@tsplus/stdlib/collections/HashMap/operations/modify"
+export * from "@tsplus/stdlib/collections/HashMap/operations/modifyHash"
+export * from "@tsplus/stdlib/collections/HashMap/operations/mutate"
+export * from "@tsplus/stdlib/collections/HashMap/operations/node"
+export * from "@tsplus/stdlib/collections/HashMap/operations/reduce"
+export * from "@tsplus/stdlib/collections/HashMap/operations/reduceWithIndex"
+export * from "@tsplus/stdlib/collections/HashMap/operations/remove"
+export * from "@tsplus/stdlib/collections/HashMap/operations/removeMany"
+export * from "@tsplus/stdlib/collections/HashMap/operations/set"
+export * from "@tsplus/stdlib/collections/HashMap/operations/setTree"
+export * from "@tsplus/stdlib/collections/HashMap/operations/size"
+export * from "@tsplus/stdlib/collections/HashMap/operations/toCollection"
+export * from "@tsplus/stdlib/collections/HashMap/operations/union"
+export * from "@tsplus/stdlib/collections/HashMap/operations/unsafeGet"
+export * from "@tsplus/stdlib/collections/HashMap/operations/update"
+export * from "@tsplus/stdlib/collections/HashMap/operations/values"
+// codegen:end
diff --git a/packages/stdlib/_src/collections/HashMap/beginMutation.ts b/packages/stdlib/_src/collections/HashMap/operations/beginMutation.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/beginMutation.ts
rename to packages/stdlib/_src/collections/HashMap/operations/beginMutation.ts
diff --git a/packages/stdlib/_src/collections/HashMap/collect.ts b/packages/stdlib/_src/collections/HashMap/operations/collect.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/collect.ts
rename to packages/stdlib/_src/collections/HashMap/operations/collect.ts
diff --git a/packages/stdlib/_src/collections/HashMap/collectWithIndex.ts b/packages/stdlib/_src/collections/HashMap/operations/collectWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/collectWithIndex.ts
rename to packages/stdlib/_src/collections/HashMap/operations/collectWithIndex.ts
diff --git a/packages/stdlib/_src/collections/HashMap/compact.ts b/packages/stdlib/_src/collections/HashMap/operations/compact.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/compact.ts
rename to packages/stdlib/_src/collections/HashMap/operations/compact.ts
diff --git a/packages/stdlib/_src/collections/HashMap/empty.ts b/packages/stdlib/_src/collections/HashMap/operations/empty.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/empty.ts
rename to packages/stdlib/_src/collections/HashMap/operations/empty.ts
diff --git a/packages/stdlib/_src/collections/HashMap/endMutation.ts b/packages/stdlib/_src/collections/HashMap/operations/endMutation.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/endMutation.ts
rename to packages/stdlib/_src/collections/HashMap/operations/endMutation.ts
diff --git a/packages/stdlib/_src/collections/HashMap/filter.ts b/packages/stdlib/_src/collections/HashMap/operations/filter.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/filter.ts
rename to packages/stdlib/_src/collections/HashMap/operations/filter.ts
diff --git a/packages/stdlib/_src/collections/HashMap/filterWithIndex.ts b/packages/stdlib/_src/collections/HashMap/operations/filterWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/filterWithIndex.ts
rename to packages/stdlib/_src/collections/HashMap/operations/filterWithIndex.ts
diff --git a/packages/stdlib/_src/collections/HashMap/flatMap.ts b/packages/stdlib/_src/collections/HashMap/operations/flatMap.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/flatMap.ts
rename to packages/stdlib/_src/collections/HashMap/operations/flatMap.ts
diff --git a/packages/stdlib/_src/collections/HashMap/flatMapWithIndex.ts b/packages/stdlib/_src/collections/HashMap/operations/flatMapWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/flatMapWithIndex.ts
rename to packages/stdlib/_src/collections/HashMap/operations/flatMapWithIndex.ts
diff --git a/packages/stdlib/_src/collections/HashMap/forEach.ts b/packages/stdlib/_src/collections/HashMap/operations/forEach.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/forEach.ts
rename to packages/stdlib/_src/collections/HashMap/operations/forEach.ts
diff --git a/packages/stdlib/_src/collections/HashMap/forEachWithIndex.ts b/packages/stdlib/_src/collections/HashMap/operations/forEachWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/forEachWithIndex.ts
rename to packages/stdlib/_src/collections/HashMap/operations/forEachWithIndex.ts
diff --git a/packages/stdlib/_src/collections/HashMap/from.ts b/packages/stdlib/_src/collections/HashMap/operations/from.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/from.ts
rename to packages/stdlib/_src/collections/HashMap/operations/from.ts
diff --git a/packages/stdlib/_src/collections/HashMap/get.ts b/packages/stdlib/_src/collections/HashMap/operations/get.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/get.ts
rename to packages/stdlib/_src/collections/HashMap/operations/get.ts
diff --git a/packages/stdlib/_src/collections/HashMap/getAssociative.ts b/packages/stdlib/_src/collections/HashMap/operations/getAssociative.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/getAssociative.ts
rename to packages/stdlib/_src/collections/HashMap/operations/getAssociative.ts
diff --git a/packages/stdlib/_src/collections/HashMap/hasHash.ts b/packages/stdlib/_src/collections/HashMap/operations/hasHash.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/hasHash.ts
rename to packages/stdlib/_src/collections/HashMap/operations/hasHash.ts
diff --git a/packages/stdlib/_src/collections/HashMap/isEmpty.ts b/packages/stdlib/_src/collections/HashMap/operations/isEmpty.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/isEmpty.ts
rename to packages/stdlib/_src/collections/HashMap/operations/isEmpty.ts
diff --git a/packages/stdlib/_src/collections/HashMap/keySet.ts b/packages/stdlib/_src/collections/HashMap/operations/keySet.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/keySet.ts
rename to packages/stdlib/_src/collections/HashMap/operations/keySet.ts
diff --git a/packages/stdlib/_src/collections/HashMap/keys.ts b/packages/stdlib/_src/collections/HashMap/operations/keys.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/keys.ts
rename to packages/stdlib/_src/collections/HashMap/operations/keys.ts
diff --git a/packages/stdlib/_src/collections/HashMap/make.ts b/packages/stdlib/_src/collections/HashMap/operations/make.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/make.ts
rename to packages/stdlib/_src/collections/HashMap/operations/make.ts
diff --git a/packages/stdlib/_src/collections/HashMap/map.ts b/packages/stdlib/_src/collections/HashMap/operations/map.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/map.ts
rename to packages/stdlib/_src/collections/HashMap/operations/map.ts
diff --git a/packages/stdlib/_src/collections/HashMap/mapWithIndex.ts b/packages/stdlib/_src/collections/HashMap/operations/mapWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/mapWithIndex.ts
rename to packages/stdlib/_src/collections/HashMap/operations/mapWithIndex.ts
diff --git a/packages/stdlib/_src/collections/HashMap/modify.ts b/packages/stdlib/_src/collections/HashMap/operations/modify.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/modify.ts
rename to packages/stdlib/_src/collections/HashMap/operations/modify.ts
diff --git a/packages/stdlib/_src/collections/HashMap/modifyHash.ts b/packages/stdlib/_src/collections/HashMap/operations/modifyHash.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/modifyHash.ts
rename to packages/stdlib/_src/collections/HashMap/operations/modifyHash.ts
diff --git a/packages/stdlib/_src/collections/HashMap/mutate.ts b/packages/stdlib/_src/collections/HashMap/operations/mutate.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/mutate.ts
rename to packages/stdlib/_src/collections/HashMap/operations/mutate.ts
diff --git a/packages/stdlib/_src/collections/HashMap/node.ts b/packages/stdlib/_src/collections/HashMap/operations/node.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/node.ts
rename to packages/stdlib/_src/collections/HashMap/operations/node.ts
diff --git a/packages/stdlib/_src/collections/HashMap/reduce.ts b/packages/stdlib/_src/collections/HashMap/operations/reduce.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/reduce.ts
rename to packages/stdlib/_src/collections/HashMap/operations/reduce.ts
diff --git a/packages/stdlib/_src/collections/HashMap/reduceWithIndex.ts b/packages/stdlib/_src/collections/HashMap/operations/reduceWithIndex.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/reduceWithIndex.ts
rename to packages/stdlib/_src/collections/HashMap/operations/reduceWithIndex.ts
diff --git a/packages/stdlib/_src/collections/HashMap/remove.ts b/packages/stdlib/_src/collections/HashMap/operations/remove.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/remove.ts
rename to packages/stdlib/_src/collections/HashMap/operations/remove.ts
diff --git a/packages/stdlib/_src/collections/HashMap/removeMany.ts b/packages/stdlib/_src/collections/HashMap/operations/removeMany.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/removeMany.ts
rename to packages/stdlib/_src/collections/HashMap/operations/removeMany.ts
diff --git a/packages/stdlib/_src/collections/HashMap/set.ts b/packages/stdlib/_src/collections/HashMap/operations/set.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/set.ts
rename to packages/stdlib/_src/collections/HashMap/operations/set.ts
diff --git a/packages/stdlib/_src/collections/HashMap/setTree.ts b/packages/stdlib/_src/collections/HashMap/operations/setTree.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/setTree.ts
rename to packages/stdlib/_src/collections/HashMap/operations/setTree.ts
diff --git a/packages/stdlib/_src/collections/HashMap/size.ts b/packages/stdlib/_src/collections/HashMap/operations/size.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/size.ts
rename to packages/stdlib/_src/collections/HashMap/operations/size.ts
diff --git a/packages/stdlib/_src/collections/HashMap/toCollection.ts b/packages/stdlib/_src/collections/HashMap/operations/toCollection.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/toCollection.ts
rename to packages/stdlib/_src/collections/HashMap/operations/toCollection.ts
diff --git a/packages/stdlib/_src/collections/HashMap/union.ts b/packages/stdlib/_src/collections/HashMap/operations/union.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/union.ts
rename to packages/stdlib/_src/collections/HashMap/operations/union.ts
diff --git a/packages/stdlib/_src/collections/HashMap/unsafeGet.ts b/packages/stdlib/_src/collections/HashMap/operations/unsafeGet.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/unsafeGet.ts
rename to packages/stdlib/_src/collections/HashMap/operations/unsafeGet.ts
diff --git a/packages/stdlib/_src/collections/HashMap/update.ts b/packages/stdlib/_src/collections/HashMap/operations/update.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/update.ts
rename to packages/stdlib/_src/collections/HashMap/operations/update.ts
diff --git a/packages/stdlib/_src/collections/HashMap/values.ts b/packages/stdlib/_src/collections/HashMap/operations/values.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashMap/values.ts
rename to packages/stdlib/_src/collections/HashMap/operations/values.ts
diff --git a/packages/stdlib/_src/collections/HashMap/patch.ts b/packages/stdlib/_src/collections/HashMap/patch.ts
new file mode 100644
index 00000000..bb7cc17d
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashMap/patch.ts
@@ -0,0 +1,4 @@
+// codegen:start {preset: barrel, include: ./patch/*.ts, prefix: "@tsplus/stdlib/collections/HashMap"}
+export * from "@tsplus/stdlib/collections/HashMap/patch/definition"
+export * from "@tsplus/stdlib/collections/HashMap/patch/operations"
+// codegen:end
diff --git a/packages/stdlib/_src/collections/HashMap/patch/definition.ts b/packages/stdlib/_src/collections/HashMap/patch/definition.ts
new file mode 100644
index 00000000..663b97dc
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashMap/patch/definition.ts
@@ -0,0 +1,113 @@
+export const HashMapPatchSym = Symbol.for("@Differ.HashMap.Patch")
+export type HashMapPatchSym = typeof HashMapPatchSym
+
+export const HashMapPatchKeySym = Symbol.for("@Differ.HashMap.Patch.Key")
+export type HashMapPatchKeySym = typeof HashMapPatchKeySym
+
+export const HashMapPatchValueSym = Symbol.for("@Differ.HashMap.Patch.Value")
+export type HashMapPatchValueSym = typeof HashMapPatchValueSym
+
+export const HashMapPatchPatchSym = Symbol.for("@Differ.HashMap.Patch.Patch")
+export type HashMapPatchPatchSym = typeof HashMapPatchPatchSym
+
+/**
+ * A patch which describes updates to a map of keys and values.
+ *
+ * @tsplus type Differ.HashMap.Patch
+ */
+export interface HashMapPatch<in out Key, in out Value, in out Patch> {
+  readonly [HashMapPatchSym]: HashMapPatchSym
+  readonly [HashMapPatchKeySym]: (_: Key) => Key
+  readonly [HashMapPatchValueSym]: (_: Value) => Value
+  readonly [HashMapPatchPatchSym]: (_: Patch) => Patch
+}
+
+/**
+ * @tsplus type Differ.HashMap.Patch.Ops
+ */
+export interface HashMapPatchOps {
+  readonly $: HashMapPatchAspects
+}
+/**
+ * @tsplus static Differ.Ops HashMap
+ */
+export const HashMapPatch: HashMapPatchOps = {
+  $: {}
+}
+
+/**
+ * @tsplus type Differ.HashMap.Patch.Aspects
+ */
+export interface HashMapPatchAspects {}
+
+/**
+ * @tsplus unify Differ.HashMap.Patch
+ */
+export function unifyHashMapPatch<X extends HashMapPatch<any, any, any>>(self: X): HashMapPatch<
+  [X] extends [{ [HashMapPatchKeySym]: (_: infer Key) => infer Key }] ? Key : never,
+  [X] extends [{ [HashMapPatchValueSym]: (_: infer Value) => infer Value }] ? Value : never,
+  [X] extends [{ [HashMapPatchPatchSym]: (_: infer Patch) => infer Patch }] ? Patch : never
+> {
+  return self
+}
+
+export abstract class BaseHashMapPatch<Key, Value, Patch>
+  implements HashMapPatch<Key, Value, Patch>
+{
+  readonly [HashMapPatchSym]: HashMapPatchSym = HashMapPatchSym
+  readonly [HashMapPatchKeySym]!: (_: Key) => Key
+  readonly [HashMapPatchValueSym]!: (_: Value) => Value
+  readonly [HashMapPatchPatchSym]!: (_: Patch) => Patch
+}
+
+export class AddHashMapPatch<Key, Value, Patch> extends BaseHashMapPatch<Key, Value, Patch> {
+  readonly _tag = "Add"
+  constructor(readonly key: Key, readonly value: Value) {
+    super()
+  }
+}
+
+export class RemoveHashMapPatch<Key, Value, Patch> extends BaseHashMapPatch<Key, Value, Patch> {
+  readonly _tag = "Remove"
+  constructor(readonly key: Key) {
+    super()
+  }
+}
+
+export class UpdateHashMapPatch<Key, Value, Patch> extends BaseHashMapPatch<Key, Value, Patch> {
+  readonly _tag = "Update"
+  constructor(readonly key: Key, readonly patch: Patch) {
+    super()
+  }
+}
+
+export class EmptyHashMapPatch<Key, Value, Patch> extends BaseHashMapPatch<Key, Value, Patch> {
+  readonly _tag = "Empty"
+}
+
+export class AndThenHashMapPatch<Key, Value, Patch> extends BaseHashMapPatch<Key, Value, Patch> {
+  readonly _tag = "AndThen"
+  constructor(
+    readonly first: HashMapPatch<Key, Value, Patch>,
+    readonly second: HashMapPatch<Key, Value, Patch>
+  ) {
+    super()
+  }
+}
+
+export type HashMapPatchInstruction =
+  | AddHashMapPatch<any, any, any>
+  | RemoveHashMapPatch<any, any, any>
+  | UpdateHashMapPatch<any, any, any>
+  | EmptyHashMapPatch<any, any, any>
+  | AndThenHashMapPatch<any, any, any>
+
+/**
+ * @tsplus macro identity
+ */
+export function hashMapPatchInstruction<Key, Value, Patch>(
+  self: HashMapPatch<Key, Value, Patch>
+): HashMapPatchInstruction {
+  // @ts-expect-error
+  return self
+}
diff --git a/packages/stdlib/_src/collections/HashMap/patch/operations.ts b/packages/stdlib/_src/collections/HashMap/patch/operations.ts
new file mode 100644
index 00000000..55d0ebe6
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashMap/patch/operations.ts
@@ -0,0 +1,6 @@
+// codegen:start {preset: barrel, include: ./operations/*.ts, prefix: "@tsplus/stdlib/collections/HashMap/patch"}
+export * from "@tsplus/stdlib/collections/HashMap/patch/operations/apply"
+export * from "@tsplus/stdlib/collections/HashMap/patch/operations/combine"
+export * from "@tsplus/stdlib/collections/HashMap/patch/operations/diff"
+export * from "@tsplus/stdlib/collections/HashMap/patch/operations/emptyPatch"
+// codegen:end
diff --git a/packages/stdlib/_src/collections/HashMap/patch/operations/apply.ts b/packages/stdlib/_src/collections/HashMap/patch/operations/apply.ts
new file mode 100644
index 00000000..be691c70
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashMap/patch/operations/apply.ts
@@ -0,0 +1,56 @@
+import { hashMapPatchInstruction } from "@tsplus/stdlib/collections/HashMap/patch/definition"
+
+/**
+ * Applies a map patch to a map of keys and values to produce a new map of
+ * keys and values values which represents the original map of keys and
+ * values updated with the changes described by this patch.
+ *
+ * @tsplus static Differ.HashMap.Patch.Aspects apply
+ * @tsplus pipeable Differ.HashMap.Patch apply
+ */
+export function apply<Key, Value, Patch>(
+  oldValue: HashMap<Key, Value>,
+  differ: Differ<Value, Patch>
+) {
+  return (self: Differ.HashMap.Patch<Key, Value, Patch>): HashMap<Key, Value> =>
+    applyLoop(differ, oldValue, List(self))
+}
+
+/**
+ * @tsplus tailRec
+ */
+function applyLoop<Key, Value, Patch>(
+  differ: Differ<Value, Patch>,
+  map: HashMap<Key, Value>,
+  patches: List<Differ.HashMap.Patch<Key, Value, Patch>>
+): HashMap<Key, Value> {
+  if (patches.isNil()) {
+    return map
+  }
+  const patch = hashMapPatchInstruction(patches.head)
+  const nextPatches = patches.tail
+  switch (patch._tag) {
+    case "Add": {
+      return applyLoop(differ, map.set(patch.key, patch.value), nextPatches)
+    }
+    case "AndThen": {
+      return applyLoop(differ, map, nextPatches.prepend(patch.second).prepend(patch.first))
+    }
+    case "Empty": {
+      return applyLoop(differ, map, nextPatches)
+    }
+    case "Remove": {
+      return applyLoop(differ, map.remove(patch.key), nextPatches)
+    }
+    case "Update": {
+      return applyLoop(
+        differ,
+        map.get(patch.key).fold(
+          map,
+          (oldValue) => map.set(patch.key, differ.patch(patch.patch, oldValue))
+        ),
+        nextPatches
+      )
+    }
+  }
+}
diff --git a/packages/stdlib/_src/collections/HashMap/patch/operations/combine.ts b/packages/stdlib/_src/collections/HashMap/patch/operations/combine.ts
new file mode 100644
index 00000000..2929b68e
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashMap/patch/operations/combine.ts
@@ -0,0 +1,13 @@
+import { AndThenHashMapPatch } from "@tsplus/stdlib/collections/HashMap/patch/definition"
+
+/**
+ * Combines two map patches to produce a new map patch that describes
+ * applying their changes sequentially.
+ *
+ * @tsplus static Differ.HashMap.Patch.Aspects combine
+ * @tsplus pipeable Differ.HashMap.Patch combine
+ */
+export function combine<Key, Value, Patch>(that: Differ.HashMap.Patch<Key, Value, Patch>) {
+  return (self: Differ.HashMap.Patch<Key, Value, Patch>): Differ.HashMap.Patch<Key, Value, Patch> =>
+    new AndThenHashMapPatch(self, that)
+}
diff --git a/packages/stdlib/_src/collections/HashMap/patch/operations/diff.ts b/packages/stdlib/_src/collections/HashMap/patch/operations/diff.ts
new file mode 100644
index 00000000..3d35925e
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashMap/patch/operations/diff.ts
@@ -0,0 +1,40 @@
+import {
+  AddHashMapPatch,
+  RemoveHashMapPatch,
+  UpdateHashMapPatch
+} from "@tsplus/stdlib/collections/HashMap/patch/definition"
+
+/**
+ * Constructs a map patch from a new and old map of keys and values and a
+ * differ for the values.
+ *
+ * @tsplus static Differ.HashMap.Patch.Ops diff
+ */
+export function diff<Key, Value, Patch>(
+  oldValue: HashMap<Key, Value>,
+  newValue: HashMap<Key, Value>,
+  differ: Differ<Value, Patch>
+): Differ.HashMap.Patch<Key, Value, Patch> {
+  const { tuple: [removed, patch] } = newValue.reduceWithIndex(
+    Tuple(oldValue, Differ.HashMap.empty<Key, Value, Patch>()),
+    ({ tuple: [map, patch] }, key, newValue) => {
+      const maybe = map.get(key)
+      switch (maybe._tag) {
+        case "Some": {
+          const valuePatch = differ.diff(maybe.value, newValue)
+          if (Equals.equals(valuePatch, differ.empty)) {
+            return Tuple(map.remove(key), patch)
+          }
+          return Tuple(map.remove(key), patch.combine(new UpdateHashMapPatch(key, valuePatch)))
+        }
+        case "None": {
+          return Tuple(map, patch.combine(new AddHashMapPatch(key, newValue)))
+        }
+      }
+    }
+  )
+  return removed.reduceWithIndex(
+    patch,
+    (patch, key, _) => patch.combine(new RemoveHashMapPatch(key))
+  )
+}
diff --git a/packages/stdlib/_src/collections/HashMap/patch/operations/emptyPatch.ts b/packages/stdlib/_src/collections/HashMap/patch/operations/emptyPatch.ts
new file mode 100644
index 00000000..f0f7e7ec
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashMap/patch/operations/emptyPatch.ts
@@ -0,0 +1,10 @@
+import { EmptyHashMapPatch } from "@tsplus/stdlib/collections/HashMap/patch/definition"
+
+/**
+ * Constructs an empty map patch.
+ *
+ * @tsplus static Differ.HashMap.Patch.Ops empty
+ */
+export function emptyPatch<Key, Value, Patch>(): Differ.HashMap.Patch<Key, Value, Patch> {
+  return new EmptyHashMapPatch()
+}
diff --git a/packages/stdlib/_src/collections/HashSet.ts b/packages/stdlib/_src/collections/HashSet.ts
index d3b548c0..1b53111e 100644
--- a/packages/stdlib/_src/collections/HashSet.ts
+++ b/packages/stdlib/_src/collections/HashSet.ts
@@ -1,29 +1,5 @@
 // codegen:start {preset: barrel, include: ./HashSet/*.ts, prefix: "@tsplus/stdlib/collections"}
-export * from "@tsplus/stdlib/collections/HashSet/add"
-export * from "@tsplus/stdlib/collections/HashSet/beginMutation"
 export * from "@tsplus/stdlib/collections/HashSet/definition"
-export * from "@tsplus/stdlib/collections/HashSet/difference"
-export * from "@tsplus/stdlib/collections/HashSet/empty"
-export * from "@tsplus/stdlib/collections/HashSet/endMutation"
-export * from "@tsplus/stdlib/collections/HashSet/equals"
-export * from "@tsplus/stdlib/collections/HashSet/every"
-export * from "@tsplus/stdlib/collections/HashSet/filter"
-export * from "@tsplus/stdlib/collections/HashSet/flatMap"
-export * from "@tsplus/stdlib/collections/HashSet/forEach"
-export * from "@tsplus/stdlib/collections/HashSet/from"
-export * from "@tsplus/stdlib/collections/HashSet/has"
-export * from "@tsplus/stdlib/collections/HashSet/intersection"
-export * from "@tsplus/stdlib/collections/HashSet/isSubset"
-export * from "@tsplus/stdlib/collections/HashSet/make"
-export * from "@tsplus/stdlib/collections/HashSet/map"
-export * from "@tsplus/stdlib/collections/HashSet/mutate"
-export * from "@tsplus/stdlib/collections/HashSet/partition"
-export * from "@tsplus/stdlib/collections/HashSet/reduce"
-export * from "@tsplus/stdlib/collections/HashSet/remove"
-export * from "@tsplus/stdlib/collections/HashSet/size"
-export * from "@tsplus/stdlib/collections/HashSet/some"
-export * from "@tsplus/stdlib/collections/HashSet/toCollection"
-export * from "@tsplus/stdlib/collections/HashSet/toggle"
-export * from "@tsplus/stdlib/collections/HashSet/union"
-export * from "@tsplus/stdlib/collections/HashSet/values"
+export * from "@tsplus/stdlib/collections/HashSet/operations"
+export * from "@tsplus/stdlib/collections/HashSet/patch"
 // codegen:end
diff --git a/packages/stdlib/_src/collections/HashSet/operations.ts b/packages/stdlib/_src/collections/HashSet/operations.ts
new file mode 100644
index 00000000..a5619baf
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashSet/operations.ts
@@ -0,0 +1,28 @@
+// codegen:start {preset: barrel, include: ./operations/*.ts, prefix: "@tsplus/stdlib/collections/HashSet"}
+export * from "@tsplus/stdlib/collections/HashSet/operations/add"
+export * from "@tsplus/stdlib/collections/HashSet/operations/beginMutation"
+export * from "@tsplus/stdlib/collections/HashSet/operations/difference"
+export * from "@tsplus/stdlib/collections/HashSet/operations/empty"
+export * from "@tsplus/stdlib/collections/HashSet/operations/endMutation"
+export * from "@tsplus/stdlib/collections/HashSet/operations/equals"
+export * from "@tsplus/stdlib/collections/HashSet/operations/every"
+export * from "@tsplus/stdlib/collections/HashSet/operations/filter"
+export * from "@tsplus/stdlib/collections/HashSet/operations/flatMap"
+export * from "@tsplus/stdlib/collections/HashSet/operations/forEach"
+export * from "@tsplus/stdlib/collections/HashSet/operations/from"
+export * from "@tsplus/stdlib/collections/HashSet/operations/has"
+export * from "@tsplus/stdlib/collections/HashSet/operations/intersection"
+export * from "@tsplus/stdlib/collections/HashSet/operations/isSubset"
+export * from "@tsplus/stdlib/collections/HashSet/operations/make"
+export * from "@tsplus/stdlib/collections/HashSet/operations/map"
+export * from "@tsplus/stdlib/collections/HashSet/operations/mutate"
+export * from "@tsplus/stdlib/collections/HashSet/operations/partition"
+export * from "@tsplus/stdlib/collections/HashSet/operations/reduce"
+export * from "@tsplus/stdlib/collections/HashSet/operations/remove"
+export * from "@tsplus/stdlib/collections/HashSet/operations/size"
+export * from "@tsplus/stdlib/collections/HashSet/operations/some"
+export * from "@tsplus/stdlib/collections/HashSet/operations/toCollection"
+export * from "@tsplus/stdlib/collections/HashSet/operations/toggle"
+export * from "@tsplus/stdlib/collections/HashSet/operations/union"
+export * from "@tsplus/stdlib/collections/HashSet/operations/values"
+// codegen:end
diff --git a/packages/stdlib/_src/collections/HashSet/add.ts b/packages/stdlib/_src/collections/HashSet/operations/add.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/add.ts
rename to packages/stdlib/_src/collections/HashSet/operations/add.ts
diff --git a/packages/stdlib/_src/collections/HashSet/beginMutation.ts b/packages/stdlib/_src/collections/HashSet/operations/beginMutation.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/beginMutation.ts
rename to packages/stdlib/_src/collections/HashSet/operations/beginMutation.ts
diff --git a/packages/stdlib/_src/collections/HashSet/difference.ts b/packages/stdlib/_src/collections/HashSet/operations/difference.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/difference.ts
rename to packages/stdlib/_src/collections/HashSet/operations/difference.ts
diff --git a/packages/stdlib/_src/collections/HashSet/empty.ts b/packages/stdlib/_src/collections/HashSet/operations/empty.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/empty.ts
rename to packages/stdlib/_src/collections/HashSet/operations/empty.ts
diff --git a/packages/stdlib/_src/collections/HashSet/endMutation.ts b/packages/stdlib/_src/collections/HashSet/operations/endMutation.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/endMutation.ts
rename to packages/stdlib/_src/collections/HashSet/operations/endMutation.ts
diff --git a/packages/stdlib/_src/collections/HashSet/equals.ts b/packages/stdlib/_src/collections/HashSet/operations/equals.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/equals.ts
rename to packages/stdlib/_src/collections/HashSet/operations/equals.ts
diff --git a/packages/stdlib/_src/collections/HashSet/every.ts b/packages/stdlib/_src/collections/HashSet/operations/every.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/every.ts
rename to packages/stdlib/_src/collections/HashSet/operations/every.ts
diff --git a/packages/stdlib/_src/collections/HashSet/filter.ts b/packages/stdlib/_src/collections/HashSet/operations/filter.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/filter.ts
rename to packages/stdlib/_src/collections/HashSet/operations/filter.ts
diff --git a/packages/stdlib/_src/collections/HashSet/flatMap.ts b/packages/stdlib/_src/collections/HashSet/operations/flatMap.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/flatMap.ts
rename to packages/stdlib/_src/collections/HashSet/operations/flatMap.ts
diff --git a/packages/stdlib/_src/collections/HashSet/forEach.ts b/packages/stdlib/_src/collections/HashSet/operations/forEach.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/forEach.ts
rename to packages/stdlib/_src/collections/HashSet/operations/forEach.ts
diff --git a/packages/stdlib/_src/collections/HashSet/from.ts b/packages/stdlib/_src/collections/HashSet/operations/from.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/from.ts
rename to packages/stdlib/_src/collections/HashSet/operations/from.ts
diff --git a/packages/stdlib/_src/collections/HashSet/has.ts b/packages/stdlib/_src/collections/HashSet/operations/has.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/has.ts
rename to packages/stdlib/_src/collections/HashSet/operations/has.ts
diff --git a/packages/stdlib/_src/collections/HashSet/intersection.ts b/packages/stdlib/_src/collections/HashSet/operations/intersection.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/intersection.ts
rename to packages/stdlib/_src/collections/HashSet/operations/intersection.ts
diff --git a/packages/stdlib/_src/collections/HashSet/isSubset.ts b/packages/stdlib/_src/collections/HashSet/operations/isSubset.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/isSubset.ts
rename to packages/stdlib/_src/collections/HashSet/operations/isSubset.ts
diff --git a/packages/stdlib/_src/collections/HashSet/make.ts b/packages/stdlib/_src/collections/HashSet/operations/make.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/make.ts
rename to packages/stdlib/_src/collections/HashSet/operations/make.ts
diff --git a/packages/stdlib/_src/collections/HashSet/map.ts b/packages/stdlib/_src/collections/HashSet/operations/map.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/map.ts
rename to packages/stdlib/_src/collections/HashSet/operations/map.ts
diff --git a/packages/stdlib/_src/collections/HashSet/mutate.ts b/packages/stdlib/_src/collections/HashSet/operations/mutate.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/mutate.ts
rename to packages/stdlib/_src/collections/HashSet/operations/mutate.ts
diff --git a/packages/stdlib/_src/collections/HashSet/partition.ts b/packages/stdlib/_src/collections/HashSet/operations/partition.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/partition.ts
rename to packages/stdlib/_src/collections/HashSet/operations/partition.ts
diff --git a/packages/stdlib/_src/collections/HashSet/reduce.ts b/packages/stdlib/_src/collections/HashSet/operations/reduce.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/reduce.ts
rename to packages/stdlib/_src/collections/HashSet/operations/reduce.ts
diff --git a/packages/stdlib/_src/collections/HashSet/remove.ts b/packages/stdlib/_src/collections/HashSet/operations/remove.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/remove.ts
rename to packages/stdlib/_src/collections/HashSet/operations/remove.ts
diff --git a/packages/stdlib/_src/collections/HashSet/size.ts b/packages/stdlib/_src/collections/HashSet/operations/size.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/size.ts
rename to packages/stdlib/_src/collections/HashSet/operations/size.ts
diff --git a/packages/stdlib/_src/collections/HashSet/some.ts b/packages/stdlib/_src/collections/HashSet/operations/some.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/some.ts
rename to packages/stdlib/_src/collections/HashSet/operations/some.ts
diff --git a/packages/stdlib/_src/collections/HashSet/toCollection.ts b/packages/stdlib/_src/collections/HashSet/operations/toCollection.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/toCollection.ts
rename to packages/stdlib/_src/collections/HashSet/operations/toCollection.ts
diff --git a/packages/stdlib/_src/collections/HashSet/toggle.ts b/packages/stdlib/_src/collections/HashSet/operations/toggle.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/toggle.ts
rename to packages/stdlib/_src/collections/HashSet/operations/toggle.ts
diff --git a/packages/stdlib/_src/collections/HashSet/union.ts b/packages/stdlib/_src/collections/HashSet/operations/union.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/union.ts
rename to packages/stdlib/_src/collections/HashSet/operations/union.ts
diff --git a/packages/stdlib/_src/collections/HashSet/values.ts b/packages/stdlib/_src/collections/HashSet/operations/values.ts
similarity index 100%
rename from packages/stdlib/_src/collections/HashSet/values.ts
rename to packages/stdlib/_src/collections/HashSet/operations/values.ts
diff --git a/packages/stdlib/_src/collections/HashSet/patch.ts b/packages/stdlib/_src/collections/HashSet/patch.ts
new file mode 100644
index 00000000..38f372a6
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashSet/patch.ts
@@ -0,0 +1,4 @@
+// codegen:start {preset: barrel, include: ./patch/*.ts, prefix: "@tsplus/stdlib/collections/HashSet"}
+export * from "@tsplus/stdlib/collections/HashSet/patch/definition"
+export * from "@tsplus/stdlib/collections/HashSet/patch/operations"
+// codegen:end
diff --git a/packages/stdlib/_src/collections/HashSet/patch/definition.ts b/packages/stdlib/_src/collections/HashSet/patch/definition.ts
new file mode 100644
index 00000000..5a175869
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashSet/patch/definition.ts
@@ -0,0 +1,86 @@
+export const HashSetPatchSym = Symbol.for("@Differ.HashSet.Patch")
+export type HashSetPatchSym = typeof HashSetPatchSym
+
+export const HashSetPatchValueSym = Symbol.for("@Differ.HashSet.Patch.Value")
+export type HashSetPatchValueSym = typeof HashSetPatchValueSym
+
+/**
+ * A patch which describes updates to a set of values.
+ *
+ * @tsplus type Differ.HashSet.Patch
+ */
+export interface HashSetPatch<in out Value> {
+  readonly [HashSetPatchSym]: HashSetPatchSym
+  readonly [HashSetPatchValueSym]: (_: Value) => Value
+}
+
+/**
+ * @tsplus type Differ.HashSet.Patch.Ops
+ */
+export interface HashSetPatchOps {
+  readonly $: HashSetPatchAspects
+}
+/**
+ * @tsplus static Differ.Ops HashSet
+ */
+export const HashSetPatch: HashSetPatchOps = {
+  $: {}
+}
+
+/**
+ * @tsplus type Differ.HashSet.Patch.Aspects
+ */
+export interface HashSetPatchAspects {}
+
+/**
+ * @tsplus unify Differ.HashSet.Patch
+ */
+export function unifyHashSetPatch<X extends HashSetPatch<any>>(self: X): HashSetPatch<
+  [X] extends [{ [HashSetPatchValueSym]: (_: infer Value) => infer Value }] ? Value : never
+> {
+  return self
+}
+
+export abstract class BaseHashSetPatch<Value> implements HashSetPatch<Value> {
+  readonly [HashSetPatchSym]: HashSetPatchSym = HashSetPatchSym
+  readonly [HashSetPatchValueSym]!: (_: Value) => Value
+}
+
+export class AddHashSetPatch<Value> extends BaseHashSetPatch<Value> {
+  readonly _tag = "Add"
+  constructor(readonly value: Value) {
+    super()
+  }
+}
+
+export class AndThenHashSetPatch<Value> extends BaseHashSetPatch<Value> {
+  readonly _tag = "AndThen"
+  constructor(readonly first: HashSetPatch<Value>, readonly second: HashSetPatch<Value>) {
+    super()
+  }
+}
+
+export class EmptyHashSetPatch<Value> extends BaseHashSetPatch<Value> {
+  readonly _tag = "Empty"
+}
+
+export class RemoveHashSetPatch<Value> extends BaseHashSetPatch<Value> {
+  readonly _tag = "Remove"
+  constructor(readonly value: Value) {
+    super()
+  }
+}
+
+export type HashSetPatchInstruction =
+  | AddHashSetPatch<any>
+  | AndThenHashSetPatch<any>
+  | EmptyHashSetPatch<any>
+  | RemoveHashSetPatch<any>
+
+/**
+ * @tsplus macro identity
+ */
+export function hashSetPatchInstruction<Value>(self: HashSetPatch<Value>): HashSetPatchInstruction {
+  // @ts-expect-error
+  return self
+}
diff --git a/packages/stdlib/_src/collections/HashSet/patch/operations.ts b/packages/stdlib/_src/collections/HashSet/patch/operations.ts
new file mode 100644
index 00000000..f01a68db
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashSet/patch/operations.ts
@@ -0,0 +1,6 @@
+// codegen:start {preset: barrel, include: ./operations/*.ts, prefix: "@tsplus/stdlib/collections/HashSet/patch"}
+export * from "@tsplus/stdlib/collections/HashSet/patch/operations/apply"
+export * from "@tsplus/stdlib/collections/HashSet/patch/operations/combine"
+export * from "@tsplus/stdlib/collections/HashSet/patch/operations/diff"
+export * from "@tsplus/stdlib/collections/HashSet/patch/operations/emptyPatch"
+// codegen:end
diff --git a/packages/stdlib/_src/collections/HashSet/patch/operations/apply.ts b/packages/stdlib/_src/collections/HashSet/patch/operations/apply.ts
new file mode 100644
index 00000000..d4efb33a
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashSet/patch/operations/apply.ts
@@ -0,0 +1,41 @@
+import { hashSetPatchInstruction } from "@tsplus/stdlib/collections/HashSet/patch/definition"
+
+/**
+ * Applies a set patch to a set of values to produce a new set of values
+ * which represents the original set of values updated with the changes
+ * described by this patch.
+ *
+ * @tsplus static Differ.HashSet.Patch.Aspects apply
+ * @tsplus pipeable Differ.HashSet.Patch apply
+ */
+export function apply<Value>(oldValue: HashSet<Value>) {
+  return (self: Differ.HashSet.Patch<Value>): HashSet<Value> => applyLoop(oldValue, List(self))
+}
+
+/**
+ * @tsplus tailRec
+ */
+function applyLoop<Value>(
+  set: HashSet<Value>,
+  patches: List<Differ.HashSet.Patch<Value>>
+): HashSet<Value> {
+  if (patches.isNil()) {
+    return set
+  }
+  const patch = hashSetPatchInstruction(patches.head)
+  const nextPatches = patches.tail
+  switch (patch._tag) {
+    case "Add": {
+      return applyLoop(set.add(patch.value), nextPatches)
+    }
+    case "AndThen": {
+      return applyLoop(set, nextPatches.prepend(patch.second).prepend(patch.first))
+    }
+    case "Empty": {
+      return applyLoop(set, nextPatches)
+    }
+    case "Remove": {
+      return applyLoop(set.remove(patch.value), nextPatches)
+    }
+  }
+}
diff --git a/packages/stdlib/_src/collections/HashSet/patch/operations/combine.ts b/packages/stdlib/_src/collections/HashSet/patch/operations/combine.ts
new file mode 100644
index 00000000..fc63db1f
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashSet/patch/operations/combine.ts
@@ -0,0 +1,13 @@
+import { AndThenHashSetPatch } from "@tsplus/stdlib/collections/HashSet/patch/definition"
+
+/**
+ * Combines two set patches to produce a new set patch that describes
+ * applying their changes sequentially.
+ *
+ * @tsplus static Differ.HashSet.Patch.Aspects combine
+ * @tsplus pipeable Differ.HashSet.Patch combine
+ */
+export function combine<Value>(that: Differ.HashSet.Patch<Value>) {
+  return (self: Differ.HashSet.Patch<Value>): Differ.HashSet.Patch<Value> =>
+    new AndThenHashSetPatch(self, that)
+}
diff --git a/packages/stdlib/_src/collections/HashSet/patch/operations/diff.ts b/packages/stdlib/_src/collections/HashSet/patch/operations/diff.ts
new file mode 100644
index 00000000..5283431e
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashSet/patch/operations/diff.ts
@@ -0,0 +1,25 @@
+import {
+  AddHashSetPatch,
+  RemoveHashSetPatch
+} from "@tsplus/stdlib/collections/HashSet/patch/definition"
+
+/**
+ * Constructs a set patch from a new set of values.
+ *
+ * @tsplus static Differ.HashSet.Patch.Ops diff
+ */
+export function diff<Value>(
+  oldValue: HashSet<Value>,
+  newValue: HashSet<Value>
+): Differ.HashSet.Patch<Value> {
+  const { tuple: [removed, patch] } = newValue.reduce(
+    Tuple(oldValue, Differ.HashSet.empty<Value>()),
+    ({ tuple: [set, patch] }, value) => {
+      if (set.has(value)) {
+        return Tuple(set.remove(value), patch)
+      }
+      return Tuple(set, patch.combine(new AddHashSetPatch(value)))
+    }
+  )
+  return removed.reduce(patch, (patch, value) => patch.combine(new RemoveHashSetPatch(value)))
+}
diff --git a/packages/stdlib/_src/collections/HashSet/patch/operations/emptyPatch.ts b/packages/stdlib/_src/collections/HashSet/patch/operations/emptyPatch.ts
new file mode 100644
index 00000000..77f84a05
--- /dev/null
+++ b/packages/stdlib/_src/collections/HashSet/patch/operations/emptyPatch.ts
@@ -0,0 +1,10 @@
+import { EmptyHashSetPatch } from "@tsplus/stdlib/collections/HashSet/patch/definition"
+
+/**
+ * Constructs an empty set patch.
+ *
+ * @tsplus static Differ.HashSet.Patch.Ops empty
+ */
+export function emptyPatch<Value>(): Differ.HashSet.Patch<Value> {
+  return new EmptyHashSetPatch()
+}
diff --git a/packages/stdlib/_src/data.ts b/packages/stdlib/_src/data.ts
index 40305554..7ea1f459 100644
--- a/packages/stdlib/_src/data.ts
+++ b/packages/stdlib/_src/data.ts
@@ -2,6 +2,7 @@ export * as atomicBoolean from "@tsplus/stdlib/data/AtomicBoolean"
 export * as atomicNumber from "@tsplus/stdlib/data/AtomicNumber"
 export * as atomicReference from "@tsplus/stdlib/data/AtomicReference"
 export * as case from "@tsplus/stdlib/data/Case"
+export * as differ from "@tsplus/stdlib/data/Differ"
 export * as duration from "@tsplus/stdlib/data/Duration"
 export * as either from "@tsplus/stdlib/data/Either"
 export * as function from "@tsplus/stdlib/data/Function"
diff --git a/packages/stdlib/_src/data/Differ.ts b/packages/stdlib/_src/data/Differ.ts
new file mode 100644
index 00000000..1dc18433
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ.ts
@@ -0,0 +1,5 @@
+// codegen:start {preset: barrel, include: ./Differ/*.ts, prefix: "@tsplus/stdlib/data"}
+export * from "@tsplus/stdlib/data/Differ/definition"
+export * from "@tsplus/stdlib/data/Differ/operations"
+export * from "@tsplus/stdlib/data/Differ/OrPatch"
+// codegen:end
diff --git a/packages/stdlib/_src/data/Differ/OrPatch.ts b/packages/stdlib/_src/data/Differ/OrPatch.ts
new file mode 100644
index 00000000..b38d9c1a
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/OrPatch.ts
@@ -0,0 +1,4 @@
+// codegen:start {preset: barrel, include: ./OrPatch/*.ts, prefix: "@tsplus/stdlib/data/Differ"}
+export * from "@tsplus/stdlib/data/Differ/OrPatch/definition"
+export * from "@tsplus/stdlib/data/Differ/OrPatch/operations"
+// codegen:end
diff --git a/packages/stdlib/_src/data/Differ/OrPatch/definition.ts b/packages/stdlib/_src/data/Differ/OrPatch/definition.ts
new file mode 100644
index 00000000..b3f8d857
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/OrPatch/definition.ts
@@ -0,0 +1,139 @@
+export const OrPatchSym = Symbol.for("@Differ.Or.Patch")
+export type OrPatchSym = typeof OrPatchSym
+
+export const OrPatchValueSym = Symbol.for("@Differ.Or.Patch.Value")
+export type OrPatchValueSym = typeof OrPatchValueSym
+
+export const OrPatchValue2Sym = Symbol.for("@Differ.Or.Patch.Value2")
+export type OrPatchValue2Sym = typeof OrPatchValueSym
+
+export const OrPatchPatchSym = Symbol.for("@Differ.Or.Patch.Patch")
+export type OrPatchPatchSym = typeof OrPatchPatchSym
+
+export const OrPatchPatch2Sym = Symbol.for("@Differ.Or.Patch.Patch2")
+export type OrPatchPatch2Sym = typeof OrPatchPatch2Sym
+
+/**
+ * A patch which describes updates to either one value or another.
+ *
+ * @tsplus type Differ.Or.Patch
+ */
+export interface OrPatch<in out Value, in out Value2, in out Patch, in out Patch2> {
+  readonly [OrPatchSym]: OrPatchSym
+  readonly [OrPatchValueSym]: (_: Value) => Value
+  readonly [OrPatchValue2Sym]: (_: Value2) => Value2
+  readonly [OrPatchPatchSym]: (_: Patch) => Patch
+  readonly [OrPatchPatch2Sym]: (_: Patch2) => Patch2
+}
+
+/**
+ * @tsplus type Differ.Or.Patch.Ops
+ */
+export interface OrPatchOps {
+  readonly $: OrPatchAspects
+}
+/**
+ * @tsplus static Differ.Ops Or
+ */
+export const OrPatch: OrPatchOps = {
+  $: {}
+}
+
+/**
+ * @tsplus type Differ.Or.Patch.Aspects
+ */
+export interface OrPatchAspects {}
+
+/**
+ * @tsplus unify Differ.Or.Patch
+ */
+export function unifyOrPatch<X extends OrPatch<any, any, any, any>>(self: X): OrPatch<
+  [X] extends [{ [OrPatchValueSym]: (_: infer Value) => infer Value }] ? Value : never,
+  [X] extends [{ [OrPatchValue2Sym]: (_: infer Value2) => infer Value2 }] ? Value2 : never,
+  [X] extends [{ [OrPatchPatchSym]: (_: infer Patch) => infer Patch }] ? Patch : never,
+  [X] extends [{ [OrPatchPatch2Sym]: (_: infer Patch2) => infer Patch2 }] ? Patch2 : never
+> {
+  return self
+}
+
+export abstract class BaseOrPatch<Value, Value2, Patch, Patch2>
+  implements OrPatch<Value, Value2, Patch, Patch2>
+{
+  readonly [OrPatchSym]: OrPatchSym = OrPatchSym
+  readonly [OrPatchValueSym]!: (_: Value) => Value
+  readonly [OrPatchValue2Sym]!: (_: Value2) => Value2
+  readonly [OrPatchPatchSym]!: (_: Patch) => Patch
+  readonly [OrPatchPatch2Sym]!: (_: Patch2) => Patch2
+}
+
+export class AndThenOrPatch<Value, Value2, Patch, Patch2>
+  extends BaseOrPatch<Value, Value2, Patch, Patch2>
+{
+  readonly _tag = "AndThen"
+  constructor(
+    readonly first: OrPatch<Value, Value2, Patch, Patch2>,
+    readonly second: OrPatch<Value, Value2, Patch, Patch2>
+  ) {
+    super()
+  }
+}
+
+export class EmptyOrPatch<Value, Value2, Patch, Patch2>
+  extends BaseOrPatch<Value, Value2, Patch, Patch2>
+{
+  readonly _tag = "Empty"
+}
+
+export class SetLeftOrPatch<Value, Value2, Patch, Patch2>
+  extends BaseOrPatch<Value, Value2, Patch, Patch2>
+{
+  readonly _tag = "SetLeft"
+  constructor(readonly value: Value) {
+    super()
+  }
+}
+
+export class SetRightOrPatch<Value, Value2, Patch, Patch2>
+  extends BaseOrPatch<Value, Value2, Patch, Patch2>
+{
+  readonly _tag = "SetRight"
+  constructor(readonly value: Value2) {
+    super()
+  }
+}
+
+export class UpdateLeftOrPatch<Value, Value2, Patch, Patch2>
+  extends BaseOrPatch<Value, Value2, Patch, Patch2>
+{
+  readonly _tag = "UpdateLeft"
+  constructor(readonly patch: Patch) {
+    super()
+  }
+}
+
+export class UpdateRightOrPatch<Value, Value2, Patch, Patch2>
+  extends BaseOrPatch<Value, Value2, Patch, Patch2>
+{
+  readonly _tag = "UpdateRight"
+  constructor(readonly patch: Patch2) {
+    super()
+  }
+}
+
+export type OrPatchInstruction =
+  | AndThenOrPatch<any, any, any, any>
+  | EmptyOrPatch<any, any, any, any>
+  | SetLeftOrPatch<any, any, any, any>
+  | SetRightOrPatch<any, any, any, any>
+  | UpdateLeftOrPatch<any, any, any, any>
+  | UpdateRightOrPatch<any, any, any, any>
+
+/**
+ * @tsplus macro identity
+ */
+export function orPatchInstruction<Value, Value2, Patch, Patch2>(
+  self: OrPatch<Value, Value2, Patch, Patch2>
+): OrPatchInstruction {
+  // @ts-expect-error
+  return self
+}
diff --git a/packages/stdlib/_src/data/Differ/OrPatch/operations.ts b/packages/stdlib/_src/data/Differ/OrPatch/operations.ts
new file mode 100644
index 00000000..49bbd933
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/OrPatch/operations.ts
@@ -0,0 +1,6 @@
+// codegen:start {preset: barrel, include: ./operations/*.ts, prefix: "@tsplus/stdlib/data/Differ/OrPatch"}
+export * from "@tsplus/stdlib/data/Differ/OrPatch/operations/apply"
+export * from "@tsplus/stdlib/data/Differ/OrPatch/operations/combine"
+export * from "@tsplus/stdlib/data/Differ/OrPatch/operations/diff"
+export * from "@tsplus/stdlib/data/Differ/OrPatch/operations/emptyPatch"
+// codegen:end
diff --git a/packages/stdlib/_src/data/Differ/OrPatch/operations/apply.ts b/packages/stdlib/_src/data/Differ/OrPatch/operations/apply.ts
new file mode 100644
index 00000000..a0da327f
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/OrPatch/operations/apply.ts
@@ -0,0 +1,77 @@
+import { orPatchInstruction } from "@tsplus/stdlib/data/Differ/OrPatch/definition"
+
+/**
+ * Applies an or patch to a value to produce a new value which represents
+ * the original value updated with the changes described by this patch.
+ *
+ * @tsplus static Differ.Or.Patch.Aspects apply
+ * @tsplus pipeable Differ.Or.Patch apply
+ */
+export function apply<Value, Value2, Patch, Patch2>(
+  oldValue: Either<Value, Value2>,
+  left: Differ<Value, Patch>,
+  right: Differ<Value2, Patch2>
+) {
+  return (self: Differ.Or.Patch<Value, Value2, Patch, Patch2>): Either<Value, Value2> =>
+    applyLoop(left, right, oldValue, List(self))
+}
+
+/**
+ * @tsplus tailRec
+ */
+function applyLoop<Value, Value2, Patch, Patch2>(
+  left: Differ<Value, Patch>,
+  right: Differ<Value2, Patch2>,
+  either: Either<Value, Value2>,
+  patches: List<Differ.Or.Patch<Value, Value2, Patch, Patch2>>
+): Either<Value, Value2> {
+  if (patches.isNil()) {
+    return either
+  }
+  const patch = orPatchInstruction(patches.head)
+  const nextPatches = patches.tail
+  switch (patch._tag) {
+    case "AndThen": {
+      return applyLoop(left, right, either, nextPatches.prepend(patch.second).prepend(patch.first))
+    }
+    case "Empty": {
+      return applyLoop(left, right, either, nextPatches)
+    }
+    case "UpdateLeft": {
+      switch (either._tag) {
+        case "Left": {
+          return applyLoop(
+            left,
+            right,
+            Either.left(left.patch(patch.patch, either.left)),
+            nextPatches
+          )
+        }
+        case "Right": {
+          return applyLoop(left, right, either, nextPatches)
+        }
+      }
+    }
+    case "UpdateRight": {
+      switch (either._tag) {
+        case "Left": {
+          return applyLoop(left, right, either, nextPatches)
+        }
+        case "Right": {
+          return applyLoop(
+            left,
+            right,
+            Either.right(right.patch(patch.patch, either.right)),
+            nextPatches
+          )
+        }
+      }
+    }
+    case "SetLeft": {
+      return applyLoop(left, right, Either.left(patch.value), nextPatches)
+    }
+    case "SetRight": {
+      return applyLoop(left, right, Either.right(patch.value), nextPatches)
+    }
+  }
+}
diff --git a/packages/stdlib/_src/data/Differ/OrPatch/operations/combine.ts b/packages/stdlib/_src/data/Differ/OrPatch/operations/combine.ts
new file mode 100644
index 00000000..5f4a7e9b
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/OrPatch/operations/combine.ts
@@ -0,0 +1,16 @@
+import { AndThenOrPatch } from "@tsplus/stdlib/data/Differ/OrPatch/definition"
+
+/**
+ * Combines two or patches to produce a new or patch that describes applying
+ * their changes sequentially.
+ *
+ * @tsplus static Differ.Or.Patch.Aspects combine
+ * @tsplus pipeable Differ.Or.Patch combine
+ */
+export function combine<Value, Value2, Patch, Patch2>(
+  that: Differ.Or.Patch<Value, Value2, Patch, Patch2>
+) {
+  return (
+    self: Differ.Or.Patch<Value, Value2, Patch, Patch2>
+  ): Differ.Or.Patch<Value, Value2, Patch, Patch2> => new AndThenOrPatch(self, that)
+}
diff --git a/packages/stdlib/_src/data/Differ/OrPatch/operations/diff.ts b/packages/stdlib/_src/data/Differ/OrPatch/operations/diff.ts
new file mode 100644
index 00000000..4d37a018
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/OrPatch/operations/diff.ts
@@ -0,0 +1,51 @@
+import {
+  EmptyOrPatch,
+  SetLeftOrPatch,
+  SetRightOrPatch,
+  UpdateLeftOrPatch,
+  UpdateRightOrPatch
+} from "@tsplus/stdlib/data/Differ/OrPatch/definition"
+
+/**
+ * Constructs an `OrPatch` from a new and old value and a differ for the
+ * values.
+ *
+ * @tsplus static Differ.Or.Patch.Ops diff
+ */
+export function diff<Value, Value2, Patch, Patch2>(
+  oldValue: Either<Value, Value2>,
+  newValue: Either<Value, Value2>,
+  left: Differ<Value, Patch>,
+  right: Differ<Value2, Patch2>
+): Differ.Or.Patch<Value, Value2, Patch, Patch2> {
+  switch (oldValue._tag) {
+    case "Left": {
+      switch (newValue._tag) {
+        case "Left": {
+          const valuePatch = left.diff(oldValue.left, newValue.left)
+          if (Equals.equals(valuePatch, left.empty)) {
+            return new EmptyOrPatch()
+          }
+          return new UpdateLeftOrPatch(valuePatch)
+        }
+        case "Right": {
+          return new SetRightOrPatch(newValue.right)
+        }
+      }
+    }
+    case "Right": {
+      switch (newValue._tag) {
+        case "Left": {
+          return new SetLeftOrPatch(newValue.left)
+        }
+        case "Right": {
+          const valuePatch = right.diff(oldValue.right, newValue.right)
+          if (Equals.equals(valuePatch, right.empty)) {
+            return new EmptyOrPatch()
+          }
+          return new UpdateRightOrPatch(valuePatch)
+        }
+      }
+    }
+  }
+}
diff --git a/packages/stdlib/_src/data/Differ/OrPatch/operations/emptyPatch.ts b/packages/stdlib/_src/data/Differ/OrPatch/operations/emptyPatch.ts
new file mode 100644
index 00000000..438baecf
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/OrPatch/operations/emptyPatch.ts
@@ -0,0 +1,15 @@
+import { EmptyOrPatch } from "@tsplus/stdlib/data/Differ/OrPatch/definition"
+
+/**
+ * Constructs an empty or patch.
+ *
+ * @tsplus static Differ.Or.Patch.Ops empty
+ */
+export function emptyPatch<Value, Value2, Patch, Patch2>(): Differ.Or.Patch<
+  Value,
+  Value2,
+  Patch,
+  Patch2
+> {
+  return new EmptyOrPatch()
+}
diff --git a/packages/stdlib/_src/data/Differ/definition.ts b/packages/stdlib/_src/data/Differ/definition.ts
new file mode 100644
index 00000000..bfe861e3
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/definition.ts
@@ -0,0 +1,84 @@
+import type { ChunkPatch } from "@tsplus/stdlib/collections/Chunk/patch/definition"
+import type { HashMapPatch } from "@tsplus/stdlib/collections/HashMap/patch/definition"
+import type { HashSetPatch } from "@tsplus/stdlib/collections/HashSet/patch/definition"
+import type { OrPatch } from "@tsplus/stdlib/data/Differ/OrPatch/definition"
+
+export const DifferSym = Symbol.for("@Differ")
+export type DifferSym = typeof DifferSym
+
+/**
+ * A `Differ<Value, Patch>` knows how to compare an old value and new value of
+ * type `Value` to produce a patch of type `Patch` that describes the
+ * differences between those values. A `Differ` also knows how to apply a patch
+ * to an old value to produce a new value that represents the old value updated
+ * with the changes described by the patch.
+ *
+ * A `Differ` can be used to construct a `FiberRef` supporting compositional
+ * updates using the `FiberRef.makePatch` constructor.
+ *
+ * The `Differ` companion object contains constructors for `Differ` values for
+ * common data types such as `Chunk`, `HashMap`, and `HashSet``. In addition,
+ * `Differ`values can be transformed using the `transform` operator and combined
+ * using the `orElseEither` and `zip` operators. This allows creating `Differ`
+ * values for arbitrarily complex data types compositionally.
+ *
+ * @tsplus type Differ
+ */
+export interface Differ<Value, Patch> {
+  readonly [DifferSym]: DifferSym
+  /**
+   * An empty patch that describes no changes.
+   */
+  readonly empty: Patch
+  /**
+   * Constructs a patch describing the updates to a value from an old value and
+   * a new value.
+   */
+  readonly diff: (oldValue: Value, newValue: Value) => Patch
+  /**
+   * Combines two patches to produce a new patch that describes the updates of
+   * the first patch and then the updates of the second patch. The combine
+   * operation should be associative. In addition, if the combine operation is
+   * commutative then joining multiple fibers concurrently will result in
+   * deterministic `FiberRef` values.
+   */
+  readonly combine: (first: Patch, second: Patch) => Patch
+  /**
+   * Applies a patch to an old value to produce a new value that is equal to the
+   * old value with the updates described by the patch.
+   */
+  readonly patch: (patch: Patch, oldValue: Value) => Value
+}
+
+export declare namespace Differ {
+  export namespace Or {
+    export type Patch<Value, Value2, Patch, Patch2> = OrPatch<Value, Value2, Patch, Patch2>
+  }
+
+  export namespace Chunk {
+    export type Patch<Value, Patch> = ChunkPatch<Value, Patch>
+  }
+
+  export namespace HashMap {
+    export type Patch<Key, Value, Patch> = HashMapPatch<Key, Value, Patch>
+  }
+
+  export namespace HashSet {
+    export type Patch<Value> = HashSetPatch<Value>
+  }
+}
+
+/**
+ * @tsplus type Differ.Ops
+ */
+export interface DifferOps {
+  readonly $: DifferAspects
+}
+export const Differ: DifferOps = {
+  $: {}
+}
+
+/**
+ * @tsplus type Differ.Aspects
+ */
+export interface DifferAspects {}
diff --git a/packages/stdlib/_src/data/Differ/operations.ts b/packages/stdlib/_src/data/Differ/operations.ts
new file mode 100644
index 00000000..d198a03a
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/operations.ts
@@ -0,0 +1,12 @@
+// codegen:start {preset: barrel, include: ./operations/*.ts, prefix: "@tsplus/stdlib/data/Differ"}
+export * from "@tsplus/stdlib/data/Differ/operations/chunk"
+export * from "@tsplus/stdlib/data/Differ/operations/environment"
+export * from "@tsplus/stdlib/data/Differ/operations/hashMap"
+export * from "@tsplus/stdlib/data/Differ/operations/hashSet"
+export * from "@tsplus/stdlib/data/Differ/operations/make"
+export * from "@tsplus/stdlib/data/Differ/operations/orElseEither"
+export * from "@tsplus/stdlib/data/Differ/operations/transform"
+export * from "@tsplus/stdlib/data/Differ/operations/update"
+export * from "@tsplus/stdlib/data/Differ/operations/updateWith"
+export * from "@tsplus/stdlib/data/Differ/operations/zip"
+// codegen:end
diff --git a/packages/stdlib/_src/data/Differ/operations/chunk.ts b/packages/stdlib/_src/data/Differ/operations/chunk.ts
new file mode 100644
index 00000000..56a50c00
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/operations/chunk.ts
@@ -0,0 +1,16 @@
+/**
+ * Constructs a differ that knows how to diff a `Chunk` of values given a
+ * differ that knows how to diff the values.
+ *
+ * @tsplus static Differ.Ops chunk
+ */
+export function chunk<Value, Patch>(
+  differ: Differ<Value, Patch>
+): Differ<Chunk<Value>, Differ.Chunk.Patch<Value, Patch>> {
+  return Differ.make({
+    empty: Differ.Chunk.empty(),
+    combine: (first, second) => first.combine(second),
+    diff: (oldValue, newValue) => Differ.Chunk.diff(oldValue, newValue, differ),
+    patch: (patch, oldValue) => patch.apply(oldValue, differ)
+  })
+}
diff --git a/packages/stdlib/_src/data/Differ/operations/environment.ts b/packages/stdlib/_src/data/Differ/operations/environment.ts
new file mode 100644
index 00000000..703b5ef8
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/operations/environment.ts
@@ -0,0 +1,13 @@
+/**
+ * Constructs a differ that knows how to diff `Env` values.
+ *
+ * @tsplus static Differ.Ops environment
+ */
+export function environment<A>(): Differ<Service.Env<A>, Service.Patch<A, A>> {
+  return Differ.make({
+    empty: Service.Patch.empty(),
+    combine: (first, second) => first.combine(second),
+    diff: (oldValue, newValue) => Service.Patch.diff(oldValue, newValue),
+    patch: (patch, oldValue) => patch.patch(oldValue)
+  })
+}
diff --git a/packages/stdlib/_src/data/Differ/operations/hashMap.ts b/packages/stdlib/_src/data/Differ/operations/hashMap.ts
new file mode 100644
index 00000000..38ec8e5c
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/operations/hashMap.ts
@@ -0,0 +1,16 @@
+/**
+ * Constructs a differ that knows how to diff a `HashMap` of keys and values given
+ * a differ that knows how to diff the values.
+ *
+ * @tsplus static Differ.Ops hashMap
+ */
+export function hashMap<Key, Value, Patch>(
+  differ: Differ<Value, Patch>
+): Differ<HashMap<Key, Value>, Differ.HashMap.Patch<Key, Value, Patch>> {
+  return Differ.make({
+    empty: Differ.HashMap.empty(),
+    combine: (first, second) => first.combine(second),
+    diff: (oldValue, newValue) => Differ.HashMap.diff(oldValue, newValue, differ),
+    patch: (patch, oldValue) => patch.apply(oldValue, differ)
+  })
+}
diff --git a/packages/stdlib/_src/data/Differ/operations/hashSet.ts b/packages/stdlib/_src/data/Differ/operations/hashSet.ts
new file mode 100644
index 00000000..fe5b3eec
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/operations/hashSet.ts
@@ -0,0 +1,13 @@
+/**
+ * Constructs a differ that knows how to diff a `HashSet` of values.
+ *
+ * @tsplus static Differ.Ops hashSet
+ */
+export function hashSet<Value>(): Differ<HashSet<Value>, Differ.HashSet.Patch<Value>> {
+  return Differ.make({
+    empty: Differ.HashSet.empty(),
+    combine: (first, second) => first.combine(second),
+    diff: (oldValue, newValue) => Differ.HashSet.diff(oldValue, newValue),
+    patch: (patch, oldValue) => patch.apply(oldValue)
+  })
+}
diff --git a/packages/stdlib/_src/data/Differ/operations/make.ts b/packages/stdlib/_src/data/Differ/operations/make.ts
new file mode 100644
index 00000000..1e2660c0
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/operations/make.ts
@@ -0,0 +1,19 @@
+import { DifferSym } from "@tsplus/stdlib/data/Differ/definition"
+
+/**
+ * Constructs a new `Differ`.
+ *
+ * @tsplus static Differ.Ops __call
+ * @tsplus static Differ.Ops make
+ */
+export function make<Value, Patch>(params: {
+  readonly empty: Patch
+  readonly diff: (oldValue: Value, newValue: Value) => Patch
+  readonly combine: (first: Patch, second: Patch) => Patch
+  readonly patch: (patch: Patch, oldValue: Value) => Value
+}): Differ<Value, Patch> {
+  return {
+    [DifferSym]: DifferSym,
+    ...params
+  }
+}
diff --git a/packages/stdlib/_src/data/Differ/operations/orElseEither.ts b/packages/stdlib/_src/data/Differ/operations/orElseEither.ts
new file mode 100644
index 00000000..10d35968
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/operations/orElseEither.ts
@@ -0,0 +1,18 @@
+/**
+ * Combines this differ and the specified differ to produce a differ that
+ * knows how to diff the sum of their values.
+ *
+ * @tsplus static Differ.Aspects orElseEither
+ * @tsplus pipeable Differ orElseEither
+ */
+export function orElseEither<Value2, Patch2>(that: Differ<Value2, Patch2>) {
+  return <Value, Patch>(
+    self: Differ<Value, Patch>
+  ): Differ<Either<Value, Value2>, Differ.Or.Patch<Value, Value2, Patch, Patch2>> =>
+    Differ.make({
+      empty: Differ.Or.empty(),
+      combine: (first, second) => first.combine(second),
+      diff: (oldValue, newValue) => Differ.Or.diff(oldValue, newValue, self, that),
+      patch: (patch, oldValue) => patch.apply(oldValue, self, that)
+    })
+}
diff --git a/packages/stdlib/_src/data/Differ/operations/transform.ts b/packages/stdlib/_src/data/Differ/operations/transform.ts
new file mode 100644
index 00000000..0b8fa162
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/operations/transform.ts
@@ -0,0 +1,16 @@
+/**
+ * Transforms the type of values that this differ knows how to differ using
+ * the specified functions that map the new and old value types to each other.
+ *
+ * @tsplus static Differ.Aspects transform
+ * @tsplus pipeable Differ transform
+ */
+export function transform<Value, Value2>(f: (value: Value) => Value2, g: (value: Value2) => Value) {
+  return <Patch>(self: Differ<Value, Patch>): Differ<Value2, Patch> =>
+    Differ.make({
+      empty: self.empty,
+      combine: (first, second) => self.combine(first, second),
+      diff: (oldValue, newValue) => self.diff(g(oldValue), g(newValue)),
+      patch: (patch, oldValue) => f(self.patch(patch, g(oldValue)))
+    })
+}
diff --git a/packages/stdlib/_src/data/Differ/operations/update.ts b/packages/stdlib/_src/data/Differ/operations/update.ts
new file mode 100644
index 00000000..4b2444c7
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/operations/update.ts
@@ -0,0 +1,11 @@
+/**
+ * Constructs a differ that just diffs two values by returning a function that
+ * sets the value to the new value. This differ does not support combining
+ * multiple updates to the value compositionally and should only be used when
+ * there is no compositional way to update them.
+ *
+ * @tsplus static Differ.Ops update
+ */
+export function update<A>(): Differ<A, (a: A) => A> {
+  return Differ.updateWith((_, a) => a)
+}
diff --git a/packages/stdlib/_src/data/Differ/operations/updateWith.ts b/packages/stdlib/_src/data/Differ/operations/updateWith.ts
new file mode 100644
index 00000000..9f763374
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/operations/updateWith.ts
@@ -0,0 +1,29 @@
+import { constant } from "@tsplus/stdlib/data/Function"
+
+/**
+ * A variant of `update` that allows specifying the function that will be used
+ * to combine old values with new values.
+ *
+ * @tsplus static Differ.Ops updateWith
+ */
+export function updateWith<A>(f: (x: A, y: A) => A): Differ<A, (a: A) => A> {
+  return Differ.make({
+    empty: identity,
+    combine: (first, second) => {
+      if (first === identity) {
+        return second
+      }
+      if (second === identity) {
+        return first
+      }
+      return (a) => second(first(a))
+    },
+    diff: (oldValue, newValue) => {
+      if (Equals.equals(oldValue, newValue)) {
+        return identity
+      }
+      return constant(newValue)
+    },
+    patch: (patch, oldValue) => f(oldValue, patch(oldValue))
+  })
+}
diff --git a/packages/stdlib/_src/data/Differ/operations/zip.ts b/packages/stdlib/_src/data/Differ/operations/zip.ts
new file mode 100644
index 00000000..7c4b4a3c
--- /dev/null
+++ b/packages/stdlib/_src/data/Differ/operations/zip.ts
@@ -0,0 +1,33 @@
+/**
+ * Combines this differ and the specified differ to produce a new differ that
+ * knows how to diff the product of their values.
+ *
+ * @tsplus static Differ.Aspects zip
+ * @tsplus pipeable Differ zip
+ */
+export function zip<Value2, Patch2>(that: Differ<Value2, Patch2>) {
+  return <Value, Patch>(
+    self: Differ<Value, Patch>
+  ): Differ<Tuple<[Value, Value2]>, Tuple<[Patch, Patch2]>> =>
+    Differ.make({
+      empty: Tuple(
+        self.empty,
+        that.empty
+      ),
+      combine: (first, second) =>
+        Tuple(
+          self.combine(first.get(0), second.get(0)),
+          that.combine(first.get(1), second.get(1))
+        ),
+      diff: (oldValue, newValue) =>
+        Tuple(
+          self.diff(oldValue.get(0), newValue.get(0)),
+          that.diff(oldValue.get(1), newValue.get(1))
+        ),
+      patch: (patch, oldValue) =>
+        Tuple(
+          self.patch(patch.get(0), oldValue.get(0)),
+          that.patch(patch.get(1), oldValue.get(1))
+        )
+    })
+}
diff --git a/packages/stdlib/_src/global.ts b/packages/stdlib/_src/global.ts
index ecf95737..e8454ff7 100644
--- a/packages/stdlib/_src/global.ts
+++ b/packages/stdlib/_src/global.ts
@@ -101,6 +101,10 @@ import { AtomicReference } from "@tsplus/stdlib/data/AtomicReference"
  * @tsplus global
  */
 import { Case } from "@tsplus/stdlib/data/Case"
+/**
+ * @tsplus global
+ */
+import { Differ } from "@tsplus/stdlib/data/Differ/definition"
 /**
  * @tsplus global
  */
diff --git a/packages/stdlib/_test/Differ.test.ts b/packages/stdlib/_test/Differ.test.ts
new file mode 100644
index 00000000..d3a3829e
--- /dev/null
+++ b/packages/stdlib/_test/Differ.test.ts
@@ -0,0 +1,116 @@
+function diffLaws<Value, Patch>(
+  differ: Differ<Value, Patch>,
+  gen: () => Value,
+  equal: (a: Value, b: Value) => boolean
+): void {
+  describe.concurrent("differ laws", () => {
+    it("combining patches is associative", () => {
+      const value1 = gen()
+      const value2 = gen()
+      const value3 = gen()
+      const value4 = gen()
+      const patch1 = differ.diff(value1, value2)
+      const patch2 = differ.diff(value2, value3)
+      const patch3 = differ.diff(value3, value4)
+      const left = differ.combine(differ.combine(patch1, patch2), patch3)
+      const right = differ.combine(patch1, differ.combine(patch2, patch3))
+      assert.isTrue(equal(differ.patch(left, value1), differ.patch(right, value1)))
+    })
+
+    it("combining a patch with an empty patch is an identity", () => {
+      const oldValue = gen()
+      const newValue = gen()
+      const patch = differ.diff(oldValue, newValue)
+      const left = differ.combine(patch, differ.empty)
+      const right = differ.combine(differ.empty, patch)
+      assert.isTrue(equal(differ.patch(left, oldValue), newValue))
+      assert.isTrue(equal(differ.patch(right, oldValue), newValue))
+    })
+
+    it("diffing a value with itself returns an empty patch", () => {
+      const value = gen()
+      assert.deepStrictEqual(differ.diff(value, value), differ.empty)
+    })
+
+    it("diffing and then patching is an identity", () => {
+      const oldValue = gen()
+      const newValue = gen()
+      const patch = differ.diff(oldValue, newValue)
+      assert.isTrue(equal(differ.patch(patch, oldValue), newValue))
+    })
+
+    it("patching with an empty patch is an identity", () => {
+      const value = gen()
+      assert.isTrue(equal(differ.patch(differ.empty, value), value))
+    })
+  })
+}
+
+const min = 1
+const max = 100
+
+function smallInt(): number {
+  return Math.floor(Math.random() * (max - min + 1) + min)
+}
+
+function randomChunk(): Chunk<number> {
+  return Chunk.fill(20, smallInt)
+}
+
+// function randomHashMap(): HashMap<number, number> {
+//   return HashMap.from(Chunk.fill(20, smallInt).zip(Chunk.fill(20, smallInt)))
+// }
+
+function randomHashSet(): HashSet<number> {
+  return HashSet.from(Chunk.fill(20, smallInt))
+}
+
+function randomEither(): Either<number, number> {
+  return Math.random() < 0.5 ? Either.left(smallInt()) : Either.right(smallInt())
+}
+
+function randomTuple(): Tuple<[number, number]> {
+  return Tuple(smallInt(), smallInt())
+}
+
+describe.concurrent("Differ", () => {
+  describe.concurrent("chunk", () => {
+    diffLaws(
+      Differ.chunk<number, (n: number) => number>(Differ.update()),
+      randomChunk,
+      Equals.equals
+    )
+  })
+
+  describe.concurrent("either", () => {
+    diffLaws(
+      Differ.update<number>().orElseEither(Differ.update<number>()),
+      randomEither,
+      Equals.equals
+    )
+  })
+
+  describe.concurrent("hashMap", () => {
+    diffLaws(
+      Differ.hashMap<number, number, (n: number) => number>(Differ.update<number>()),
+      () => HashMap(Tuple(1, 2), Tuple(3, 4), Tuple(5, 6)),
+      Equals.equals
+    )
+  })
+
+  describe.concurrent("hashSet", () => {
+    diffLaws(
+      Differ.hashSet<number>(),
+      randomHashSet,
+      Equals.equals
+    )
+  })
+
+  describe.concurrent("tuple", () => {
+    diffLaws(
+      Differ.update<number>().zip(Differ.update<number>()),
+      randomTuple,
+      Equals.equals
+    )
+  })
+})
diff --git a/yarn.lock b/yarn.lock
index 85c9a1fa..8ce2f3b6 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -315,12 +315,12 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@changesets/apply-release-plan@npm:^6.0.3":
-  version: 6.0.3
-  resolution: "@changesets/apply-release-plan@npm:6.0.3"
+"@changesets/apply-release-plan@npm:^6.0.4":
+  version: 6.0.4
+  resolution: "@changesets/apply-release-plan@npm:6.0.4"
   dependencies:
     "@babel/runtime": ^7.10.4
-    "@changesets/config": ^2.1.0
+    "@changesets/config": ^2.1.1
     "@changesets/get-version-range-type": ^0.3.2
     "@changesets/git": ^1.4.1
     "@changesets/types": ^5.1.0
@@ -332,7 +332,7 @@ __metadata:
     prettier: ^1.19.1
     resolve-from: ^5.0.0
     semver: ^5.4.1
-  checksum: e40cac11719faf00f6573a647202941737408739f30ab534c0a2d69e6b2247940882dac521f254b936f7321e6ffac5dd104b9efaa2f2ccf429002f7f4cf2fc4c
+  checksum: 2004339f6daf45b282ae0020903d21796076954453b210d3c7935c01247293d0042d994e982e1bc582b61bfa47bd763b7d323635cb19fcd6a9a0e928d8da8358
   languageName: node
   linkType: hard
 
@@ -370,18 +370,18 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@changesets/cli@npm:^2.24.1":
-  version: 2.24.1
-  resolution: "@changesets/cli@npm:2.24.1"
+"@changesets/cli@npm:^2.24.2":
+  version: 2.24.2
+  resolution: "@changesets/cli@npm:2.24.2"
   dependencies:
     "@babel/runtime": ^7.10.4
-    "@changesets/apply-release-plan": ^6.0.3
+    "@changesets/apply-release-plan": ^6.0.4
     "@changesets/assemble-release-plan": ^5.2.0
     "@changesets/changelog-git": ^0.1.12
-    "@changesets/config": ^2.1.0
+    "@changesets/config": ^2.1.1
     "@changesets/errors": ^0.1.4
     "@changesets/get-dependents-graph": ^1.3.3
-    "@changesets/get-release-plan": ^3.0.12
+    "@changesets/get-release-plan": ^3.0.13
     "@changesets/git": ^1.4.1
     "@changesets/logger": ^0.0.5
     "@changesets/pre": ^1.0.12
@@ -409,13 +409,13 @@ __metadata:
     tty-table: ^4.1.5
   bin:
     changeset: bin.js
-  checksum: 1860969140fbdfd834e4fcb983dccf8e01cf2d5e7fe48eb793318c0411934e6abd1811711a61b1b379fc23b69a5c625354c85d3162045ef4ec726315a7e0ff2b
+  checksum: ac0d29bd67b1107d6b8600b3b42c8041fd754378ed2424f60c97e4b84a29ef7b779f4f57d8728e4e164e2cd6756b9f60bf8036784f306a368cc736d34740cb3d
   languageName: node
   linkType: hard
 
-"@changesets/config@npm:^2.1.0":
-  version: 2.1.0
-  resolution: "@changesets/config@npm:2.1.0"
+"@changesets/config@npm:^2.1.1":
+  version: 2.1.1
+  resolution: "@changesets/config@npm:2.1.1"
   dependencies:
     "@changesets/errors": ^0.1.4
     "@changesets/get-dependents-graph": ^1.3.3
@@ -424,7 +424,7 @@ __metadata:
     "@manypkg/get-packages": ^1.1.3
     fs-extra: ^7.0.1
     micromatch: ^4.0.2
-  checksum: 0b7ba7ea965739ede9b935efd8d582ed0c939e3df1b147db93c6572e799b3feb1634036e0222926bf223a5e680b9ff433edddf9d670400a3e7a4986f17c27ed1
+  checksum: 12b47efd06f9ca19f00a170517dad0e2041c2f285eff308c37e955893d24e981addc941ae545e23f9507628674ef2b9321d7423fc495bc17d00ea09066d68fc7
   languageName: node
   linkType: hard
 
@@ -460,18 +460,18 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@changesets/get-release-plan@npm:^3.0.12":
-  version: 3.0.12
-  resolution: "@changesets/get-release-plan@npm:3.0.12"
+"@changesets/get-release-plan@npm:^3.0.13":
+  version: 3.0.13
+  resolution: "@changesets/get-release-plan@npm:3.0.13"
   dependencies:
     "@babel/runtime": ^7.10.4
     "@changesets/assemble-release-plan": ^5.2.0
-    "@changesets/config": ^2.1.0
+    "@changesets/config": ^2.1.1
     "@changesets/pre": ^1.0.12
     "@changesets/read": ^0.5.7
     "@changesets/types": ^5.1.0
     "@manypkg/get-packages": ^1.1.3
-  checksum: 383b325c770344b89dfb417996a311390ea718af638f20833124bf2a493cb614ba3603eb01ff7294d48aa211d99d6fda85bf069e426daf5ebc9ded4c857f0055
+  checksum: 0e07169f9f83aa3aec072e0b3f96ef60dbb6d878d496fbbf312cfb0fe953953887a2d69008cee991c22b9fea4a2feebc9c1d783c10829be32cf19fde05e85c9d
   languageName: node
   linkType: hard
 
@@ -1013,10 +1013,10 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@types/node@npm:*, @types/node@npm:^18.6.3":
-  version: 18.6.3
-  resolution: "@types/node@npm:18.6.3"
-  checksum: 38495b8fd27200d2b7ab9ccd8c1e2475d2411fba15330f2cba869a85ef79dd42382a2658c8dd298ace8c21ed3bfafcdea408faecd74928b144377d07d00e7c8c
+"@types/node@npm:*, @types/node@npm:^18.6.4":
+  version: 18.6.4
+  resolution: "@types/node@npm:18.6.4"
+  checksum: fc453dd2b541f5812ba1a8f957f577727cf2d8aee886f1d5c03eb153b2b3373d2e0953c5bd2b7a5b184073bc317f54ec91f1ec4830a58eda4a833e90654021de
   languageName: node
   linkType: hard
 
@@ -7413,12 +7413,12 @@ __metadata:
     "@babel/core": ^7.18.10
     "@babel/plugin-transform-modules-commonjs": ^7.18.6
     "@changesets/changelog-github": ^0.4.6
-    "@changesets/cli": ^2.24.1
+    "@changesets/cli": ^2.24.2
     "@effect-ts/build-utils": 0.40.3
     "@effect-ts/core": ^0.60.2
     "@repo-tooling/eslint-plugin-dprint": ^0.0.4
     "@tsplus/installer": 0.0.132
-    "@types/node": ^18.6.3
+    "@types/node": ^18.6.4
     "@types/rimraf": ^3.0.2
     "@typescript-eslint/eslint-plugin": ^5.32.0
     "@typescript-eslint/parser": ^5.32.0