Patches

A patch is a bounded sequence of operations against one tree, applied atomically. Applying it advances the tree’s revision by exactly one - never more, never less, and never on a patch that carries no operations. A provider that computed a patch against an earlier revision than the session currently holds gets refused and resynced with a full tree rather than having the patch silently misapplied; see what a refused update looks like for the complete set of ways a patch or a tree can be rejected.

The operation vocabulary itself - what an operation targets, what it carries, and which shapes are valid against which node kinds - is defined in ui-model/src/MacroDeck.Ui.Model/Patches/ rather than restated here; treat that source as the operation reference, and this page as the rule that governs how any of them apply.

In practice you rarely construct a patch by hand: MacroDeck.Ui’s reactive runtime computes and emits the minimal patch for you from a state change - see Reactive updates. Reach for the operations directly only when you are serving a tree straight from MacroDeck.Ui.Model, without the DSL.