Skip to content

Latest commit

 

History

History
72 lines (59 loc) · 1.93 KB

BACON.md

File metadata and controls

72 lines (59 loc) · 1.93 KB
Raw

Bacon.js compatibility

For those prefering object oriented API, Francis provides francis/bacon module which adds observable methods to EventStream and Property prototypes. Because the stream semantics are almost same in Bacon and Francis, francis/bacon can also be used as a a drop-in replacement module for baconjs (see the differences below).

This module also implements Bacon's function construction rules and other JS-related API changes.

-import B from "baconjs"
+import B from "francis/bacon"

B.once("Bacon")
  .map(x => "Hello " + x + "!")
  .map(".toUpperCase")
  .onValue(console.log)

Differences to Bacon

Although the general stream and transaction semantics are same, there are few differences, mainly because of the implementation differences:

  • Francis does not distinguish Initial and Next events. If your code uses (or assumes) Bacon.Initial, it will break

  • Francis does not support eventTransformer for from* observable factory functions (at least yet)

  • Due to internal optimizations, latest subscribers receive their emit first from the upstream whereas in Bacon the order is opposite. In transactions, this is not the issue due to atomic updates but if your code otherwise relies on this undocumented feature, it will break. For example:

const msg = F.once("tsers")
msg.log("x")
msg.log("y")
// Francis output
// > y tsers
// > x tsers
// > y <end>
// > x <end>
// Bacon output
// > x tsers
// > y tsers
// > x <end>
// > y <end>

Non-implemented operators

The following operators are yet to be implemented:

  • withHandler
  • toString
  • Desc
  • fromESObservable
  • $.asEventStream
  • retry
  • try
  • withDescription
  • inspect
  • withStateMachine
  • decode
  • endOnError
  • toESObservable
  • groupBy
  • holdWhen
  • bufferWithTime(f)