# Immutable Data Over Mutable State

> Replace in-place mutation with a pure transform returning new data, so state transitions are reproducible.

Record: `algo:no-mutable`
Kind: Architectural Rules
Canonical: https://banes-lab.com/ontology/algorithms#algo-no-mutable
Closure: https://banes-lab.com/json/records/algo/no-mutable/closure

## composes

- [Computation Core](https://banes-lab.com/records/algo/computation-core.md)