# Separate what was braided

Principle `separate-what-was-braided`. Complection is two independent concerns woven together so that neither can change alone.

Prefer immutable values and pure functions. Define a behavior once, with its input, output, and failures as types, and derive each interface from that definition. Historical facts stay true, but they report what happened; they do not decide what happens next.

Read the full section in the [uncomplect skill](/skills/uncomplect#hickey-separate-what-was-braided).

## Quotes

> It means to interleave or entwine or braid.

matthiasn/talk-transcripts. *Simple Made Easy*, talk transcript., 00:31:36 ([hickey-complect](/bibliography#hickey-complect))

## Related
- [Complect](/terms/complect)
- [Compose](/terms/compose)
- [Simple](/terms/simple)

## Skills
- [uncomplect](/skills/uncomplect)

## Sources
- Hickey, Rich. *Simple Made Easy*. Strange Loop, 2011. [Link](https://www.youtube.com/watch?v=SxdOUGdseq4). ([simple-made-easy](/bibliography#simple-made-easy))
- matthiasn/talk-transcripts. *Simple Made Easy*, talk transcript. [Link](https://github.com/matthiasn/talk-transcripts/blob/master/Hickey_Rich/SimpleMadeEasy.md). ([simple-made-easy-transcript](/bibliography#simple-made-easy-transcript))