paralleldrive/aidd/aidd-observe

const constant = Observe.fromConstant(42);
const combined = Observe.fromProperties({ a: db.observe.resources.a, b: db.observe.resources.b });
const [count, setCount] = Observe.createState(0);

const doubled = Observe.withMap(count, n => n * 2);
const isDev = Observe.withMap(service.type, t => t === 'development');
const max = Observe.withFilter(
  Observe.fromProperties({ a, b }),
  ({ a, b }) => Math.max(a, b)
);
const withFallback = Observe.withDefault('unknown', maybeName);

const first = await Observe.toPromise(service.states);

export const isDevelopment = memoize((service: Pick<EnvironmentService, 'type'>) =>
  Observe.withMap(service.type, type => type === 'development')
);

Observe.withFilter(
  Observe.fromProperties({ a: db.observe.resources.a, b: db.observe.resources.b }),
  ({ a, b }) => Math.max(a, b)
);

fn whenAddingOrUsingObserve() {
  Constraints {
    Use Observe.fromConstant for static values
    Use Observe.fromProperties to combine multiple observables
    Use Observe.withFilter when mapping and/or filtering
    Use Observe.createState for mutable state with a setter
    Call unobserve() when cleaning up (e.g. component unmount)
  }
}