feat: added A.differenceWith

__tests__/Array/differenceWith.test.ts

@@ -0,0 +1,48 @@
+import { expectType } from 'ts-expect'
+
+import { A, D, F, O, flow, pipe } from '../..'
+
+type Obj = {
+  readonly a?: number
+  readonly b?: number
+  readonly c?: number
+}
+
+describe('differenceWith', () => {
+  it('provides correct types', () => {
+    expectType<ReadonlyArray<string>>(
+      A.differenceWith(['', 'hello', 'world'],[''], F.identity),
+    )
+  })
+
+  it('returns a correct result', () => {
+    expect(
+      A.differenceWith<Obj>([{ a: 1 }, { b: 2 }],[{ a: 1 }, { c: 3 }], F.identity),
+    ).toEqual([{ b: 2 }])
+    expect(
+      A.differenceWith<{a:number}>([{a:1}, {a:2}], [{a:1}], D.get('a'))
+    ).toEqual([{a:2}])
+    expect(
+      A.differenceWith([{a:{a1:1}}, {a:{a1:2}}], [{a:{a1:1}}], D.get('a'))
+    ).toEqual([{a:{a1:2}}])
+    expect(
+      A.differenceWith([{a:{a1:1}}, {a:{a1:2}}], [{a:{a1:1}}], flow(D.get('a'),O.flatMap(D.get('a1'))))
+    ).toEqual([{a:{a1:2}}])
+  })
+
+  it('*', () => {
+    expect(A.differenceWith([1, 2, 3, 4],[3, 4, 5, 6], F.identity)).toEqual([1, 2])
+  })
+})
+
+describe('difference (pipe)', () => {
+  it('provides correct types', () => {
+    expectType<ReadonlyArray<number>>(
+      pipe([5, 2, 3, 5, 6], A.differenceWith([5, 2, 3, 1, 5, 4],F.identity)),
+    )
+  })
+
+  it('*', () => {
+    expect(pipe([5, 2, 3, 5, 6], A.differenceWith([5, 2, 3, 1, 5, 4],F.identity))).toEqual([6])
+  })
+})

docs/api/generated/_array.mdx

@@ -106,6 +106,21 @@ A.difference([1, 2, 3, 4], [3, 4, 5, 6]) // → [1, 2]
 pipe([5, 2, 3, 5, 6], A.difference([5, 2, 3, 1, 5, 4])) // → [6]
 ```
 
+### differenceWith
+
+Returns elements from the first array, not existing in the second array, based on a comparison function.
+
+
+```ts
+function differenceWith<A>(xs: Array<A>, ys: Array<A>, fn: (x: A) => unknown): Array<A>
+function differenceWith<A>(ys: Array<A>, fn: (x: A) => unknown): (xs: Array<A>) => Array<A>
+```
+
+```ts
+A.differenceWith([1, 2, 3, 4],[3, 4, 5, 6], F.equals) // → [1, 2]
+pipe([5, 2, 3, 5, 6], A.differenceWith([5, 2, 3, 1, 5, 4],F.equals)) // → [6]
+```
+
 ### drop
 
 Returns a new array that does not contain the first `n` elements of the provided array, or an empty array if `n` is either less than `0` or greater than the length of the provided array.

src/Array/Array.res

@@ -662,6 +662,15 @@ let any = (xs, predicateFn) => Belt.Array.someU(xs, (. value) => predicateFn(val
 @gentype
 let difference = (xs, ys) => xs->uniq->reject(value => includes(ys, value))
 
+%comment(
+  "Returns elements from the first array, not existing in the second array, based on a comparison function."
+)
+@gentype
+let differenceWith = (xs, ys, selectFn) => {
+  let _ys = ys->uniq->Belt.Array.map(selectFn)
+  xs->uniq->reject(value => _ys->Belt.Array.someU((. y) => y == selectFn(value)))
+}
+
 %comment("Returns union of two arrays.")
 @gentype
 let union = (xs, ys) => xs->concat(ys)->uniq

src/Array/Array.ts

@@ -55,3 +55,8 @@ export declare function flatMap<A, B>(
   xs: Array<A>,
   fn: (value: A) => B | Array<B>,
 ): Array<B>
+export declare function differenceWith<A>(
+  xs: Array<A>,
+  ys: Array<A>,
+  fn: (x: A) => unknown,
+): Array<A>

src/Array/index.ts

@@ -782,6 +782,19 @@ export declare function difference<A>(ys: Array<A>): (xs: Array<A>) => Array<A>
 
 export declare function difference<A>(xs: Array<A>, ys: Array<A>): Array<A>
 
+/** Returns elements from the first array, not existing in the second array, based on a comparison function. */
+
+export declare function differenceWith<A>(
+  xs: Array<A>,
+  ys: Array<A>,
+  fn: (x: A) => unknown,
+): Array<A>
+
+export declare function differenceWith<A>(
+  ys: Array<A>,
+  fn: (x: A) => unknown,
+): (xs: Array<A>) => Array<A>
+
 /** Returns union of two arrays. */
 
 export declare function union<A>(ys: Array<A>): (xs: Array<A>) => Array<A>