Assembly Line a.k.a. ffffff

A simple set of utililties, to help with building assembly lines in JS.

The Why

• Assembly lines help in implementing complex flows, in a manner -- easy to comprehend and maintain.
• Considerably improves readability.
• Allows for a hybrid-approach, by bringing together concepts from FP and Non-FP patterns.

Example

/* Process a list of orders with a flow. */
feed(Orders, flow(
	verifyStock,
	verifyPayment,
	dispatch,
	sendMail,
));

For more examples, check the examples dir.

# Or run the following (with node v8+):
$ node ./examples/cheatsheet.js

Installation

$ npm install ffffff

Use Cases

• Data pipelines.

• Asset pipelines.

• Complex and ever-changing business flows.

Keys

• Simple functions are stiched together to compose complex flows.

• The same object is passed to all the functions in a flow, as the only argument.

• Returning false from a function, affects the flow of the all downstream functions. Utility functions help in deciding on, how the flow is affected.

Notes

• The name flow, is a delibarate choice, to prevent confusing them with traditional pipes.

• Assembly lines are similar to unix pipes, builder pattern and the pipe-filter pattern from functional languages. Yet, there are some key differentiators:

  • Assembly lines feed the same entity to all the functions in a flow. They do not feed their return values downstream (like pipes / pipes-and-filters).

  • Builder pattern has a specific purpose, building a complex object; where as assembly lines are meant to be a generic pattern in managing complex flows, which might include the building of complex objects.

• When a flow looks complex, break it into sub-flows.

• The library doesn't have any dependencies.

• The package name ffffff represents the primary utilitiy functions of the library. The lack of availability of the name -- assembly-line, al-js and their likes -- with NPM played a part in choosing such an odd name. There are a few more reasons to the name:

  • False plays a key role in controling the flow.

  • The lib is all about functions.

  • All the key functions start with the letter, F.

  • And ffffff is also the hex code of white.

Development

Setup

$ sh ./setup.sh

ToDo

• Support async flows to process items parallelly.

• Write some examples and include a few of them in the ReadMe.

• Add some example bots. Especially, a batcher, a timer and an apiFetcher.

• Port the package to other languages, esp. to Python.

• If possible, write tests for the cheatsheet example.

• Document the API.