StateReaderTaskEither: add missing Bifunctor, Alt instances

CHANGELOG.md

@@ -31,6 +31,8 @@ high state of flux, you're at risk of it changing without notice.
     - add `toggle` (@ryota-ka)
   - `TaskEither`
     - add `tryCatchK` (@DenisFrezzato)
+  - `StateReaderTaskEither`
+    - add missing `Bifunctor`, `Alt` instances (@gcanti)
 
 # 2.4.4
 

docs/modules/StateReaderTaskEither.ts.md

@@ -525,7 +525,7 @@ Added in v2.0.0
 **Signature**
 
 ```ts
-export const stateReaderTaskEither: Monad4<URI> & MonadThrow4<URI> & MonadTask4<URI> = ...
+export const stateReaderTaskEither: Monad4<URI> & Bifunctor4<URI> & Alt4<URI> & MonadTask4<URI> & MonadThrow4<URI> = ...
 ```
 
 Added in v2.0.0

src/StateReaderTaskEither.ts

@@ -1,10 +1,14 @@
 /**
  * @since 2.0.0
  */
+import { Alt4 } from './Alt'
+import { Bifunctor4 } from './Bifunctor'
 import { Either } from './Either'
 import { IO } from './IO'
 import { IOEither } from './IOEither'
 import { Monad4 } from './Monad'
+import { MonadTask4 } from './MonadTask'
+import { MonadThrow4 } from './MonadThrow'
 import { pipeable } from './pipeable'
 import { Reader } from './Reader'
 import { ReaderEither } from './ReaderEither'
@@ -15,8 +19,6 @@ import { Task } from './Task'
 import { TaskEither } from './TaskEither'
 
 import ReaderTaskEither = RTE.ReaderTaskEither
-import { MonadThrow4 } from './MonadThrow'
-import { MonadTask4 } from './MonadTask'
 
 const T = getStateM(RTE.readerTaskEither)
 
@@ -267,12 +269,15 @@ export function chainReaderTaskEitherK<R, E, A, B>(
 /**
  * @since 2.0.0
  */
-export const stateReaderTaskEither: Monad4<URI> & MonadThrow4<URI> & MonadTask4<URI> = {
+export const stateReaderTaskEither: Monad4<URI> & Bifunctor4<URI> & Alt4<URI> & MonadTask4<URI> & MonadThrow4<URI> = {
   URI,
   map: T.map,
   of: right,
   ap: T.ap,
   chain: T.chain,
+  bimap: (fea, f, g) => s => RTE.readerTaskEither.bimap(fea(s), f, ([a, s]) => [g(a), s]),
+  mapLeft: (fea, f) => s => RTE.readerTaskEither.mapLeft(fea(s), f),
+  alt: (fx, fy) => s => RTE.readerTaskEither.alt(fx(s), () => fy()(s)),
   fromIO: rightIO,
   fromTask: rightTask,
   throwError: left

test/StateReaderTaskEither.ts

@@ -51,6 +51,52 @@ describe('StateReaderTaskEither', () => {
     })
   })
 
+  describe('Bifunctor', () => {
+    it('bimap', async () => {
+      const gt2 = (n: number): boolean => n > 2
+      const len = (s: string): number => s.length
+      const e1 = await RTE.run(_.evalState(_.stateReaderTaskEither.bimap(_.right('aaa'), gt2, len), {}), {})
+      assert.deepStrictEqual(e1, E.right(3))
+      const e2 = await RTE.run(_.evalState(_.stateReaderTaskEither.bimap(_.left(3), gt2, len), {}), {})
+      assert.deepStrictEqual(e2, E.left(true))
+    })
+
+    it('mapLeft', async () => {
+      const gt2 = (n: number): boolean => n > 2
+      const e = await RTE.run(_.evalState(_.stateReaderTaskEither.mapLeft(_.left(3), gt2), {}), {})
+      assert.deepStrictEqual(e, E.left(true))
+    })
+  })
+
+  describe('Alt', () => {
+    it('alt', async () => {
+      const e1 = await RTE.run(
+        _.evalState(
+          _.stateReaderTaskEither.alt(_.right('a'), () => _.left(1)),
+          {}
+        ),
+        {}
+      )
+      assert.deepStrictEqual(e1, E.right('a'))
+      const e2 = await RTE.run(
+        _.evalState(
+          _.stateReaderTaskEither.alt(_.left(1), () => _.right('b')),
+          {}
+        ),
+        {}
+      )
+      assert.deepStrictEqual(e2, E.right('b'))
+      const e3 = await RTE.run(
+        _.evalState(
+          _.stateReaderTaskEither.alt(_.left(1), () => _.left(2)),
+          {}
+        ),
+        {}
+      )
+      assert.deepStrictEqual(e3, E.left(2))
+    })
+  })
+
   it('execState', async () => {
     const ma = _.right('aaa')
     const s = {}