withDiff()

When writing incrementally-computed signals it is convenient (and usually more performant) to incrementally compute the diff too.

You can use this function to wrap the return value of a computed signal function to indicate that the diff should be used instead of calculating a new one with AtomOptions.computeDiff.

Example

const count = atom('count', 0)
const double = computed('double', (prevValue) => {
  const nextValue = count.value * 2
  if (isUninitialized(prevValue)) {
    return nextValue
  }
  return withDiff(nextValue, nextValue - prevValue)
}, { historyLength: 10 })

Signature

withDiff<Value, Diff>(value: Value, diff: Diff): WithDiff<Value, Diff>;

Type parameters

• Value
• Diff

Parameters

Name	Type	Description
value	Value	The value.
diff	Diff	The diff.

Returns

WithDiff<Value, Diff>

Defined in: signia/src/Computed.ts:69