Computed Values

Computed values (compute) are for derivations. Use them when you want to transform data without the semantic overhead of “success” or “failure” that Guards provide.

Usage

Computes take a name, a list of dependencies, and a transform function.

import { source, compute } from '@pulse-js/core';

const firstName = source('Alice');
const lastName = source('Smith');

const fullName = compute('full-name', [firstName, lastName], (first, last) => {
  return `${first} ${last}`; // "Alice Smith"
});

Characteristics

• Memoized: They only re-calculate when inputs change.
• Pure: They should not have side effects.
• Observable: You can subscribe to them or use them in Guards.

When to use Compute vs Guard?

Feature	Compute (compute)	Guard (guard)
Purpose	Data Transformation	Business Logic / Validation
Return Type	Any Value	Boolean/Promise (mostly)
Has Status?	No	Yes (ok, fail, pending)
Has Reason?	No	Yes