IOEither: add apFirstW and apSecondW

gcanti · Oct 26, 2021 · 12f4e38 · 12f4e38
1 parent 7d244d3
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diff --git a/docs/modules/IOEither.ts.md b/docs/modules/IOEither.ts.md
@@ -35,7 +35,9 @@ Added in v2.0.0
   - [of](#of)
 - [combinators](#combinators)
   - [apFirst](#apfirst)
+  - [apFirstW](#apfirstw)
   - [apSecond](#apsecond)
+  - [apSecondW](#apsecondw)
   - [chainEitherK](#chaineitherk)
   - [chainEitherKW](#chaineitherkw)
   - [chainFirst](#chainfirst)
@@ -294,6 +296,20 @@ export declare const apFirst: <E, B>(second: IOEither<E, B>) => <A>(first: IOEit
 
 Added in v2.0.0
 
+## apFirstW
+
+Less strict version of [`apFirst`](#apfirst).
+
+**Signature**
+
+```ts
+export declare const apFirstW: <E2, A, B>(
+  second: IOEither<E2, B>
+) => <E1>(first: IOEither<E1, A>) => IOEither<E2 | E1, A>
+```
+
+Added in v2.12.0
+
 ## apSecond
 
 Combine two effectful actions, keeping only the result of the second.
@@ -308,6 +324,20 @@ export declare const apSecond: <E, B>(second: IOEither<E, B>) => <A>(first: IOEi
 
 Added in v2.0.0
 
+## apSecondW
+
+Less strict version of [`apSecond`](#apsecond).
+
+**Signature**
+
+```ts
+export declare const apSecondW: <E2, A, B>(
+  second: IOEither<E2, B>
+) => <E1>(first: IOEither<E1, A>) => IOEither<E2 | E1, B>
+```
+
+Added in v2.12.0
+
 ## chainEitherK
 
 **Signature**

diff --git a/src/IOEither.ts b/src/IOEither.ts
@@ -577,6 +577,16 @@ export const apFirst =
   /*#__PURE__*/
   apFirst_(ApplyPar)
 
+/**
+ * Less strict version of [`apFirst`](#apfirst).
+ *
+ * @category combinators
+ * @since 2.12.0
+ */
+export const apFirstW: <E2, A, B>(
+  second: IOEither<E2, B>
+) => <E1>(first: IOEither<E1, A>) => IOEither<E1 | E2, A> = apFirst as any
+
 /**
  * Combine two effectful actions, keeping only the result of the second.
  *
@@ -589,6 +599,16 @@ export const apSecond =
   /*#__PURE__*/
   apSecond_(ApplyPar)
 
+/**
+ * Less strict version of [`apSecond`](#apsecond).
+ *
+ * @category combinators
+ * @since 2.12.0
+ */
+export const apSecondW: <E2, A, B>(
+  second: IOEither<E2, B>
+) => <E1>(first: IOEither<E1, A>) => IOEither<E1 | E2, B> = apSecond as any
+
 /**
  * @category instances
  * @since 2.8.4

diff --git a/test/IOEither.ts b/test/IOEither.ts
@@ -92,10 +92,22 @@ describe('IOEither', () => {
       U.deepStrictEqual(pipe(_.right('a'), _.apFirst(_.right('b')))(), E.right('a'))
     })
 
+    it('apFirstW', () => {
+      const fa = _.right<'Foo', string>('a')
+      const fb = _.right<'Bar', number>(1)
+      U.deepStrictEqual(pipe(fa, _.apFirstW(fb))(), E.right('a'))
+    })
+
     it('apSecond', () => {
       U.deepStrictEqual(pipe(_.right('a'), _.apSecond(_.right('b')))(), E.right('b'))
     })
 
+    it('apSecondW', () => {
+      const fa = _.right<'Foo', string>('a')
+      const fb = _.right<'Bar', number>(1)
+      U.deepStrictEqual(pipe(fa, _.apSecondW(fb))(), E.right(1))
+    })
+
     it('chain', () => {
       const f = (a: string) => (a.length > 2 ? _.right(a.length) : _.left('foo'))
       U.deepStrictEqual(pipe(_.right('foo'), _.chain(f))(), E.right(3))