feat: adds Do syntax for modules

All modules now export bindTo and Bind

src/Observable.ts

@@ -185,3 +185,27 @@ export {
    */
   separate
 }
+
+/**
+ * @category Do
+ * @since 0.6.11
+ */
+export function bindTo<K extends string, A>(name: K): (fa: Observable<A>) => Observable<{ [P in K]: A }> {
+  return map(a => ({ [name]: a } as { [P in K]: A }))
+}
+
+/**
+ * @category Do
+ * @since 0.6.11
+ */
+export function bind<K extends string, A, B>(
+  name: Exclude<K, keyof A>,
+  f: (a: A) => Observable<B>
+): (fa: Observable<A>) => Observable<{ [P in keyof A | K]: P extends keyof A ? A[P] : B }> {
+  return chain(a =>
+    pipe(
+      f(a),
+      map(b => ({ ...a, [name]: b } as any))
+    )
+  )
+}

src/ObservableEither.ts

@@ -14,7 +14,7 @@ import { MonadObservable2 } from './MonadObservable'
 import { Observable } from 'rxjs'
 import { Task } from 'fp-ts/lib/Task'
 import { getEitherM } from 'fp-ts/lib/EitherT'
-import { pipeable } from 'fp-ts/lib/pipeable'
+import { pipe, pipeable } from 'fp-ts/lib/pipeable'
 
 const T = getEitherM(R.observable)
 
@@ -191,3 +191,29 @@ export {
    */
   mapLeft
 }
+
+/**
+ * @category Do
+ * @since 0.6.11
+ */
+export function bindTo<K extends string, E, A>(
+  name: K
+): (fa: ObservableEither<E, A>) => ObservableEither<E, { [P in K]: A }> {
+  return map(a => ({ [name]: a } as { [P in K]: A }))
+}
+
+/**
+ * @category Do
+ * @since 0.6.11
+ */
+export function bind<K extends string, E, A, B>(
+  name: Exclude<K, keyof A>,
+  f: (a: A) => ObservableEither<E, B>
+): (fa: ObservableEither<E, A>) => ObservableEither<E, { [P in keyof A | K]: P extends keyof A ? A[P] : B }> {
+  return chain(a =>
+    pipe(
+      f(a),
+      map(b => ({ ...a, [name]: b } as any))
+    )
+  )
+}

src/ReaderObservable.ts

@@ -4,7 +4,7 @@
 import { Observable } from 'rxjs'
 import { getReaderM } from 'fp-ts/lib/ReaderT'
 import * as R from './Observable'
-import { pipeable } from 'fp-ts/lib/pipeable'
+import { pipe, pipeable } from 'fp-ts/lib/pipeable'
 import { IO } from 'fp-ts/lib/IO'
 import { Monad2 } from 'fp-ts/lib/Monad'
 import { Monoid } from 'fp-ts/lib/Monoid'
@@ -258,3 +258,29 @@ export {
    */
   separate
 }
+
+/**
+ * @category Do
+ * @since 0.6.11
+ */
+export function bindTo<K extends string, R, A>(
+  name: K
+): (fa: ReaderObservable<R, A>) => ReaderObservable<R, { [P in K]: A }> {
+  return map(a => ({ [name]: a } as { [P in K]: A }))
+}
+
+/**
+ * @category Do
+ * @since 0.6.11
+ */
+export function bind<K extends string, R, A, B>(
+  name: Exclude<K, keyof A>,
+  f: (a: A) => ReaderObservable<R, B>
+): (fa: ReaderObservable<R, A>) => ReaderObservable<R, { [P in keyof A | K]: P extends keyof A ? A[P] : B }> {
+  return chain(a =>
+    pipe(
+      f(a),
+      map(b => ({ ...a, [name]: b } as any))
+    )
+  )
+}

src/ReaderObservableEither.ts

@@ -7,7 +7,7 @@ import { MonadObservable3 } from './MonadObservable'
 import { MonadThrow3 } from 'fp-ts/lib/MonadThrow'
 import { Bifunctor3 } from 'fp-ts/lib/Bifunctor'
 import { getReaderM } from 'fp-ts/lib/ReaderT'
-import { pipeable } from 'fp-ts/lib/pipeable'
+import { pipe, pipeable } from 'fp-ts/lib/pipeable'
 import { Observable } from 'rxjs'
 
 /**
@@ -194,3 +194,33 @@ export {
    */
   mapLeft
 }
+
+// DO
+
+/**
+ * @category Do
+ * @since 0.6.11
+ */
+export function bindTo<K extends string, R, E, A>(
+  name: K
+): (fa: ReaderObservableEither<R, E, A>) => ReaderObservableEither<R, E, { [P in K]: A }> {
+  return map(a => ({ [name]: a } as { [P in K]: A }))
+}
+
+/**
+ * @category Do
+ * @since 0.6.11
+ */
+export function bind<K extends string, R, E, A, B>(
+  name: Exclude<K, keyof A>,
+  f: (a: A) => ReaderObservableEither<R, E, B>
+): (
+  fa: ReaderObservableEither<R, E, A>
+) => ReaderObservableEither<R, E, { [P in keyof A | K]: P extends keyof A ? A[P] : B }> {
+  return chain(a =>
+    pipe(
+      f(a),
+      map(b => ({ ...a, [name]: b } as any))
+    )
+  )
+}

src/StateReaderObservableEither.ts

@@ -217,3 +217,37 @@ export {
    */
   mapLeft
 }
+
+// DO SYNTAX
+
+/**
+ * @category Do
+ * @since 0.6.11
+ */
+export function bindTo<K extends string>(
+  name: K
+): <S, R, E, A>(fa: StateReaderObservableEither<S, R, E, A>) => StateReaderObservableEither<S, R, E, { [P in K]: A }> {
+  return fa =>
+    pipe(
+      fa,
+      map(value => ({ [name]: value } as any))
+    )
+}
+
+/**
+ * @category Do
+ * @since 0.6.11
+ */
+export function bind<K extends string, S, R, E, A, B>(
+  name: Exclude<K, keyof A>,
+  f: (a: A) => StateReaderObservableEither<S, R, E, B>
+): (
+  fa: StateReaderObservableEither<S, R, E, A>
+) => StateReaderObservableEither<S, R, E, { [P in keyof A | K]: P extends keyof A ? A[P] : B }> {
+  return chain(a =>
+    pipe(
+      f(a),
+      map(b => ({ ...a, [name]: b } as any))
+    )
+  )
+}

test/Observable.ts

@@ -7,6 +7,7 @@ import * as T from 'fp-ts/lib/Task'
 import { identity } from 'fp-ts/lib/function'
 
 import { observable as R } from '../src'
+import { pipe } from 'fp-ts/lib/pipeable'
 
 describe('Observable', () => {
   it('of', () => {
@@ -206,4 +207,16 @@ describe('Observable', () => {
     const t = await R.toTask(R.of(1))()
     assert.deepStrictEqual(t, 1)
   })
+
+  it('do notation', async () => {
+    const t = await pipe(
+      R.of(1),
+      R.bindTo('a'),
+      R.bind('b', () => R.of('b'))
+    )
+      .pipe(bufferTime(10))
+      .toPromise()
+
+    assert.deepStrictEqual(t, [{ a: 1, b: 'b' }])
+  })
 })

test/ObservableEither.ts

@@ -255,4 +255,16 @@ describe('ObservableEither', () => {
       assert.deepStrictEqual(e1, e2)
     })
   })
+
+  it('do notation', async () => {
+    const t = await pipe(
+      _.right(1),
+      _.bindTo('a'),
+      _.bind('b', () => _.right('b'))
+    )
+      .pipe(bufferTime(10))
+      .toPromise()
+
+    assert.deepStrictEqual(t, [E.right({ a: 1, b: 'b' })])
+  })
 })

test/ReaderObservable.ts

@@ -298,4 +298,16 @@ describe('ReaderObservable', () => {
     const x = await _.run(pipe(_.of('a'), _.chainTaskK(f)), undefined)
     assert.deepStrictEqual(x, 1)
   })
+
+  it('do notation', async () => {
+    const t = await pipe(
+      _.of(1),
+      _.bindTo('a'),
+      _.bind('b', () => _.of('b'))
+    )(undefined)
+      .pipe(bufferTime(10))
+      .toPromise()
+
+    assert.deepStrictEqual(t, [{ a: 1, b: 'b' }])
+  })
 })

test/ReaderObservableEither.ts

@@ -125,4 +125,17 @@ describe('ReaderObservable', () => {
     const x = await robe({})()
     assert.deepStrictEqual(x, [E.right(1)])
   })
+
+  // robe should expose right
+  it('do notation', async () => {
+    const t = await pipe(
+      ROBE.of(1),
+      ROBE.bindTo('a'),
+      ROBE.bind('b', () => ROBE.of('b'))
+    )(undefined)
+      .pipe(bufferTime(10))
+      .toPromise()
+
+    assert.deepStrictEqual(t, [E.right({ a: 1, b: 'b' })])
+  })
 })

test/StateReaderObservableEither.ts

@@ -82,4 +82,17 @@ describe('stateReaderObservableEither', () => {
     const x = await srobe(2)()
     assert.deepStrictEqual(x, [E.right(1)])
   })
+
+  // should expose of
+  it('do notation', async () => {
+    const srobe = pipe(
+      SROBE.right(1),
+      SROBE.bindTo('a'),
+      SROBE.bind('b', () => SROBE.right('b')),
+      buffer
+    )
+
+    const x = await srobe('state')('reader')()
+    assert.deepStrictEqual(x, [E.right([{ a: 1, b: 'b' }, 'state'])])
+  })
 })