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https://github.com/ivan-kleshnin/reactive-polyglot
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https://github.com/ivan-kleshnin/reactive-polyglot
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- Host: GitHub
- URL: https://github.com/ivan-kleshnin/reactive-polyglot
- Owner: ivan-kleshnin
- Created: 2016-01-25T10:18:58.000Z (almost 9 years ago)
- Default Branch: master
- Last Pushed: 2019-03-15T05:57:14.000Z (over 5 years ago)
- Last Synced: 2023-02-28T19:26:44.495Z (over 1 year ago)
- Topics: baconjs, comparison, frp, kefir, mostjs, reactive, reactivity, rxjs, xstream
- Language: JavaScript
- Homepage:
- Size: 39.1 KB
- Stars: 69
- Watchers: 3
- Forks: 5
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- Changelog: history.md
Awesome Lists containing this project
README
# Reactive polyglot
**`R.`** [(Ramda)](http://ramdajs.com/0.19.1/index.html) stands for standard functional toolkit.
### Comparison notes
Operator counterparts aren't and can't be fully equivalent.
"Kinda the same" – is the current definition.
The following projects, were created with different goals and tradeoffs in mind, so every comparison
and analogy is subjective and can be argued. The presence of some operator is not necessary good, as
well as the abscence is not necessary bad.
Note, that primitives differ for each library. In descriptions, we broadly refer to all the "observable
primitives" as **streams***, though, technically speaking, some of them are rather stream-like entities.
To find something, search for a term you know.
## API
### Create
#### Create an empty stream
* KefirJS: [`never`](http://kefirjs.github.io/kefir/#never)
* MostJS: [`empty`](https://github.com/cujojs/most/blob/master/docs/api.md#mostempty)
* RxJS: [`of`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/of.md)
* XStream: [`empty`](https://github.com/staltz/xstream#of)
#### Create a stream from a single value
* KefirJS: [`constant`](http://kefirjs.github.io/kefir/#constant)
* MostJS: [`of`](https://github.com/cujojs/most/blob/master/docs/api.md#mostjust), [`just`](https://github.com/cujojs/most/blob/master/docs/api.md#mostjust)
* RxJS: [`of`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/of.md), [`just`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/return.md)
* XStream: [`of`](https://github.com/staltz/xstream#of)
#### Create a stream from an array
* KefirJS: [`sequentially`](http://kefirjs.github.io/kefir/#sequentially)
* MostJS: [`from`](https://github.com/cujojs/most/blob/master/docs/api.md#mostfrom)
* RxJS: [`from`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/from.md), [`of`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/of.md)
* XStream: [`from`](https://github.com/staltz/xstream#from), [`fromArray`](https://github.com/staltz/xstream#fromArray)
#### Create a stream from a promise
* KefirJS: [`fromPromise`](http://kefirjs.github.io/kefir/#from-promise)
* MostJS: [`fromPromise`](https://github.com/cujojs/most/blob/master/docs/api.md#mostfrompromise)
* RxJS: [`fromPromise`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/frompromise.md)
* XStream: [`fromPromise`](https://github.com/staltz/xstream#fromPromise)
#### Create a stream from an event
* KefirJS: [`fromEvents`](http://kefirjs.github.io/kefir/#from-event)
* MostJS: [`fromEvent`](https://github.com/cujojs/most/blob/master/docs/api.md#mostfromevent)
* RxJS: [`fromEvent`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/fromevent.md)
* XStream: [`fromEvent`](https://github.com/staltz/xstream/blob/master/EXTRA_DOCS.md#fromEvent)
#### Create a stream from a callback
* KefirJS: [`stream`](http://kefirjs.github.io/kefir/#stream), [`fromCallback`](http://kefirjs.github.io/kefir/#from-callback), [`fromNodeCallback`](http://kefirjs.github.io/kefir/#from-node-callback), [`fromPoll`](http://kefirjs.github.io/kefir/#from-poll)
* MostJS: `new Stream`
* RxJS: `new Observable`, `bindCallback`, `bindNodeCallback`
* XStream: `? (make a promise first)`
#### Prepend a stream with a value
* KefirJS: [`merge`](http://kefirjs.github.io/kefir/#merge) `+` [`constant`](http://kefirjs.github.io/kefir/#constant)
* MostJS: `startWith`
* RxJS: [`startWith`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/startwith.md)
* XStream: `startWith`
### Transform (data events)
#### Map value one-to-one
* KefirJS: [`map`](http://kefirjs.github.io/kefir/#map)
* MostJS: `map`, `constant`
* RxJS: [`map`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/select.md), `mapTo`
* XStream: `map`
#### Filter value by a predicate
* KefirJS: [`filter`](http://kefirjs.github.io/kefir/#filter)
* MostJS: `filter`
* RxJS: [`filter`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/where.md)
* XStream: `filter`
#### Skip N initial values
* KefirJS: [`skip`](http://kefirjs.github.io/kefir/#skip)
* MostJS: `skip`
* RxJS: [`skip`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/skip.md)
* XStream: `drop`
#### Take N initial values
* KefirJS: [`take`](http://kefirjs.github.io/kefir/#take)
* MostJS: `take`
* RxJS: [`take`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/take.md)
* XStream: `take`
#### Make a value from an accumulator and a next value
* KefirJS: [`scan`](http://kefirjs.github.io/kefir/#scan)
* MostJS: `scan`
* RxJS: [`scan`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/scan.md)
* XStream: `fold`
### Combine
#### Merge multiple streams together
* KefirJS: [`merge`](http://kefirjs.github.io/kefir/#merge)
* MostJS: `merge`
* RxJS: [`merge`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/merge.md)
* XStream: `merge`
Pay attention that Kefir's `merge` accepts arrays while others are variadic.
#### Combine multiple streams together
* KefirJS: [`combine`](http://kefirjs.github.io/kefir/#combine)
* MostJS: `combine`
* RxJS: [`combineLatest`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/combinelatest.md)
* XStream: `combine`
#### Sample a stream by another stream
* KefirJS: [`combine`](http://kefirjs.github.io/kefir/#combine), [`sampledBy`](http://kefirjs.github.io/kefir/#obs-sampled-by)
* MostJS: `sample`, `sampleWith`
* RxJS: [`sample`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/sample.md), [`withLatestFrom`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/withlatestfrom.md)
* XStream: `sampleCombine`
#### Chain streams sequentially
* KefirJS: [`flatMapConcat`](http://kefirjs.github.io/kefir/#flat-map-concat)
* MostJS: [`concatMap`](https://github.com/cujojs/most/blob/master/docs/api.md#concatmap)
* RxJS: [`concatMap`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/concatmap.md)
* XStream: `map + flattenSequentially`
---
### Create
Create stream from non-stream values.
KefirJS
MostJS
RxJS
XStream
interval
periodic
interval + map
periodic
repeat
of + R.range
repeat
of + R.range
?
iterate
generate
?
?
generate
generate
?
### Mapper
Modify events one to one.
KefirJS
MostJS
RxJS
XStream
delay
delay
delay
combine(delay(500))
– (map)
timestamp
timestamp
– (map)
### Transforms
Modify events * to *.
MostJS
RxJS
XStream
chain / flatMap
flatMap
map + flattenConcurrently
map + switch
switchMap / flatMapLatest
map + flatten
join
mergeAll
flatten
loop
scan + map
fold + map
– (custom)
bufferWithCount
?
### Filters
Skip events by predicate or signal.
MostJS
RxJS
XStream
skipRepeats
distinctUntilChanged
dropRepeats
skipRepeatsWith
– (scan)
dropRepeats
slice
skip + take
drop + take
skipWhile
skipWhile
fold + filter + map
takeWhile
takeWhile
filter + endWhen
since / skipUntil
skipUntil
fold + filter + map
until / takeUntil
takeUntil
filter + endWhen
during
window + take(1)
?
### Combinators
Combine multiple streams into single.
MostJS
RxJS
XStream
zip
zip
?
concat
concat
concat
ap
combineLatest
?
### Side effects
Produce side effect for every event.
MostJS
RxJS
XStream
tap
do / tap
debug
### Ending
Operators which target **end** event somehow.
MostJS
RxJS
XStream
empty
empty
empty
never
never
never
continueWith
?
concat
### Concurrency
MostJS
RxJS
– (custom)
amb / race
### History
MostJS
RxJS
– (custom)
### Design diffs
#### RxJS
1. Three primitives: `Observer`, `Observable`, `Subject`.
2. Observables end on error.
3. Provides API to handle errors.
3. Does not provide API to handle ending.
#### KefirJS
1. Two primitives: `Stream` and `Property` (like XStream).
2. Observables does not end on error (by default).
3. Provides API to handle errors.
4. Provides API to handle ending.
#### MostJS
1. One primitive: `Stream` (+ community-driven).
2. Separate packages for [subject-like](https://github.com/TylorS/most-subject) and [property-like](https://github.com/mostjs/hold) primitives.
3. Provides API to handle errors.
4. Provides API to handle ending.
#### XStream
1. Two primitives: `Stream` and `MemoryStream` (like KefirJS).
2. Always multicast. A Stream is like an RxJS Subject.
3. Streams end on error.
#### Common
RxJS does not emit initial `scan` value as event (use `startWith` for that).
```js
Rx.Observable.interval(100).map(x => 1)
.scan(add, 0);
.subscribe(console.log); // 1--2--3--...
Most.periodic(100, 1)
.scan(add, 0);
.observe(console.log); // 0--1--2--3--...
```
### Found docs / API quirks
#### MostJS
`startWith` vs `sampleWith` vs `continueWith` + `recoverWith` vs `skipRepeatsWith`
(val vs none vs func vs stream)
`tap` is listed in "Transform" section.
#### RxJS
`startWith` is listed in "Combine" section.
`mergeAll` is listed in "Combine" section.
`distinct` is not listed in "Filtering" section.
`takeUntil` is not listed in "Filtering" section.
`just` / `return` should be deprecated in favor of `of`.
`fromArray` should be deprecated in favor of `from`.
### Links
[bacon-vs-kefir](https://github.com/rpominov/kefir/blob/master/bacon-vs-kefir-api.md) – BaconJS vs KefirJS API comparison
[dataflows](https://github.com/ivan-kleshnin/dataflows) – web arch. dataflow comparison
[stream-conversions](https://github.com/TylorS/stream-conversions) – tool for cross-library stream conversions
### Additional Read
https://github.com/cujojs/most/issues/171
https://twitter.com/rpominov/status/689566111734599683
https://github.com/zenparsing/es-observable/issues/66
# Reactive polyglot
**`R.`** [(Ramda)](http://ramdajs.com/0.19.1/index.html) stands for standard functional toolkit.
### Comparison notes
Operator counterparts aren't and can't be fully equivalent.
"Kinda the same" – is the current definition.
The following projects, were created with different goals and tradeoffs in mind, so every comparison
and analogy is subjective and can be argued. The presence of some operator is not necessary good, as
well as the abscence is not necessary bad.
Note, that primitives differ for each library. In descriptions, we broadly refer to all the "observable
primitives" as **streams***, though, technically speaking, some of them are rather stream-like entities.
To find something, search for a term you know.
## API
### Create
#### Create an empty stream
* KefirJS: [`never`](http://kefirjs.github.io/kefir/#never)
* MostJS: [`empty`](https://github.com/cujojs/most/blob/master/docs/api.md#mostempty)
* RxJS: [`of`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/of.md)
* XStream: [`empty`](https://github.com/staltz/xstream#of)
#### Create a stream from a single value
* KefirJS: [`constant`](http://kefirjs.github.io/kefir/#constant)
* MostJS: [`of`](https://github.com/cujojs/most/blob/master/docs/api.md#mostjust), [`just`](https://github.com/cujojs/most/blob/master/docs/api.md#mostjust)
* RxJS: [`of`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/of.md), [`just`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/return.md)
* XStream: [`of`](https://github.com/staltz/xstream#of)
#### Create a stream from an array
* KefirJS: [`sequentially`](http://kefirjs.github.io/kefir/#sequentially)
* MostJS: [`from`](https://github.com/cujojs/most/blob/master/docs/api.md#mostfrom)
* RxJS: [`from`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/from.md), [`of`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/of.md)
* XStream: [`from`](https://github.com/staltz/xstream#from), [`fromArray`](https://github.com/staltz/xstream#fromArray)
#### Create a stream from a promise
* KefirJS: [`fromPromise`](http://kefirjs.github.io/kefir/#from-promise)
* MostJS: [`fromPromise`](https://github.com/cujojs/most/blob/master/docs/api.md#mostfrompromise)
* RxJS: [`fromPromise`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/frompromise.md)
* XStream: [`fromPromise`](https://github.com/staltz/xstream#fromPromise)
#### Create a stream from an event
* KefirJS: [`fromEvents`](http://kefirjs.github.io/kefir/#from-event)
* MostJS: [`fromEvent`](https://github.com/cujojs/most/blob/master/docs/api.md#mostfromevent)
* RxJS: [`fromEvent`](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/fromevent.md)
* XStream: [`fromEvent`](https://github.com/staltz/xstream/blob/master/EXTRA_DOCS.md#fromEvent)
#### Create a stream from a callback
* KefirJS: [`stream`](http://kefirjs.github.io/kefir/#stream), [`fromCallback`](http://kefirjs.github.io/kefir/#from-callback), [`fromNodeCallback`](http://kefirjs.github.io/kefir/#from-node-callback), [`fromPoll`](http://kefirjs.github.io/kefir/#from-poll)
* MostJS: `new Stream`
* RxJS: `new Observable`, `bindCallback`, `bindNodeCallback`
* XStream: `? (make a promise first)`
#### Prepend a stream with a value
* KefirJS: [`merge`](http://kefirjs.github.io/kefir/#merge) `+` [`constant`](http://kefirjs.github.io/kefir/#constant)
* MostJS: `startWith`
* RxJS: `startWith`
* XStream: `startWith`
### Transform (data events)
#### Map value one-to-one
* KefirJS: [`map`](http://kefirjs.github.io/kefir/#map)
* MostJS: `map`, `constant`
* RxJS: `map`, `mapTo`
* XStream: `map`
#### Filter value by a predicate
* KefirJS: [`filter`](http://kefirjs.github.io/kefir/#filter)
* MostJS: `filter`
* RxJS: `filter`
* XStream: `filter`
#### Skip N initial values
* KefirJS: [`skip`](http://kefirjs.github.io/kefir/#skip)
* MostJS: `skip`
* RxJS: `skip`
* XStream: `drop`
#### Take N initial values
* KefirJS: [`take`](http://kefirjs.github.io/kefir/#take)
* MostJS: `take`
* RxJS: `take`
* XStream: `take`
#### Make a value from an accumulator and a next value
* KefirJS: [`scan`](http://kefirjs.github.io/kefir/#scan)
* MostJS: `scan`
* RxJS: `scan`
* XStream: `fold`
### Combine
#### Merge multiple streams together
* KefirJS: [`merge`](http://kefirjs.github.io/kefir/#merge)
* MostJS: `merge`
* RxJS: `merge`
* XStream: `merge`
Pay attention that Kefir's `merge` accepts arrays while others are variadic.
#### Combine multiple streams together
* KefirJS: [`combine`](http://kefirjs.github.io/kefir/#combine)
* MostJS: `combine`
* RxJS: `combineLatest`
* XStream: `combine`
#### Sample a stream by another stream
* KefirJS: [`combine`](http://kefirjs.github.io/kefir/#combine), [`sampledBy`](http://kefirjs.github.io/kefir/#obs-sampled-by)
* MostJS: `sample`, `sampleWith`
* RxJS: `sample`, `withLatestFrom`
* XStream: `sampleCombine`
#### Chain streams sequentially
* KefirJS: [`flatMapConcat`](http://kefirjs.github.io/kefir/#flat-map-concat)
* MostJS: `concatMap`
* RxJS: `concatMap`
* XStream: `map + flattenSequentially`
---
### Create
Create stream from non-stream values.
KefirJS
MostJS
RxJS
XStream
interval
periodic
interval + map
periodic
repeat
of + R.range
repeat
of + R.range
?
iterate
generate
?
?
generate
generate
?
### Mapper
Modify events one to one.
KefirJS
MostJS
RxJS
XStream
delay
delay
delay
combine(delay(500))
– (map)
timestamp
timestamp
– (map)
### Transforms
Modify events * to *.
MostJS
RxJS
XStream
chain / flatMap
flatMap
map + flattenConcurrently
map + switch
switchMap / flatMapLatest
map + flatten
join
mergeAll
flatten
loop
scan + map
fold + map
– (custom)
bufferWithCount
?
### Filters
Skip events by predicate or signal.
MostJS
RxJS
XStream
skipRepeats
distinctUntilChanged
dropRepeats
skipRepeatsWith
– (scan)
dropRepeats
slice
skip + take
drop + take
skipWhile
skipWhile
fold + filter + map
takeWhile
takeWhile
filter + endWhen
since / skipUntil
skipUntil
fold + filter + map
until / takeUntil
takeUntil
filter + endWhen
during
window + take(1)
?
### Combinators
Combine multiple streams into single.
MostJS
RxJS
XStream
zip
zip
?
concat
concat
concat
ap
combineLatest
?
### Side effects
Produce side effect for every event.
MostJS
RxJS
XStream
tap
do / tap
debug
### Ending
Operators which target **end** event somehow.
MostJS
RxJS
XStream
empty
empty
empty
never
never
never
continueWith
?
concat
### Concurrency
MostJS
RxJS
– (custom)
amb / race
### History
MostJS
RxJS
– (custom)
### Design diffs
#### RxJS
1. Three primitives: `Observer`, `Observable`, `Subject`.
2. Observables end on error.
3. Provides API to handle errors.
3. Does not provide API to handle ending.
#### KefirJS
1. Two primitives: `Stream` and `Property` (like XStream).
2. Observables does not end on error (by default).
3. Provides API to handle errors.
4. Provides API to handle ending.
#### MostJS
1. One primitive: `Stream` (+ community-driven).
2. Separate packages for [subject-like](https://github.com/TylorS/most-subject) and [property-like](https://github.com/mostjs/hold) primitives.
3. Provides API to handle errors.
4. Provides API to handle ending.
#### XStream
1. Two primitives: `Stream` and `MemoryStream` (like KefirJS).
2. Always multicast. A Stream is like an RxJS Subject.
3. Streams end on error.
#### Common
RxJS does not emit initial `scan` value as event (use `startWith` for that).
```js
Rx.Observable.interval(100).map(x => 1)
.scan(add, 0);
.subscribe(console.log); // 1--2--3--...
Most.periodic(100, 1)
.scan(add, 0);
.observe(console.log); // 0--1--2--3--...
```
### Found docs / API quirks
#### MostJS
`startWith` vs `sampleWith` vs `continueWith` + `recoverWith` vs `skipRepeatsWith`
(val vs none vs func vs stream)
`tap` is listed in "Transform" section.
#### RxJS
`startWith` is listed in "Combine" section.
`mergeAll` is listed in "Combine" section.
`distinct` is not listed in "Filtering" section.
`takeUntil` is not listed in "Filtering" section.
`just` / `return` should be deprecated in favor of `of`.
`fromArray` should be deprecated in favor of `from`.
### Links
[bacon-vs-kefir](https://github.com/rpominov/kefir/blob/master/bacon-vs-kefir-api.md) – BaconJS vs KefirJS API comparison
[dataflows](https://github.com/ivan-kleshnin/dataflows) – web arch. dataflow comparison
[stream-conversions](https://github.com/TylorS/stream-conversions) – tool for cross-library stream conversions
### Additional Read
https://github.com/cujojs/most/issues/171
https://twitter.com/rpominov/status/689566111734599683
https://github.com/zenparsing/es-observable/issues/66