Function reduceSignal

Creates a WriteableSignal similar to array.reduce: Every time a value is set, callbackFn is run with the previous value to create a new value.

Param: initialValue

The signal's initial value

Param: callbackFn

The callback run when the signal is set that will create its value

Param: options

The equality function that will run after callbackFn

Returns

A writable signal whose output value is run through the callbackFn.

Example

const accumulateValue = reduceSignal(1, (prior, cur) => prior + cur);
console.log(accumulateValue()); // 1
accumulateValue.set(5);
console.log(accumulateValue()); // 6
accumulateValue.update(x => x + 1);
console.log(accumulateValue()); // 13

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