haunted/lib/use-memo.js

Hooks for web components

import { hook, Hook } from "./hook";
/**
 * @function
 * @template T
 * @param  {() => T} fn function to memoize
 * @param  {unknown[]} values dependencies to the memoized computation
 * @return {T} The next computed value
 */
const useMemo = hook(class extends Hook {
    value;
    values;
    constructor(id, state, fn, values) {
        super(id, state);
        this.value = fn();
        this.values = values;
    }
    update(fn, values) {
        if (this.hasChanged(values)) {
            this.values = values;
            this.value = fn();
        }
        return this.value;
    }
    hasChanged(values = []) {
        return values.some((value, i) => this.values[i] !== value);
    }
});
export { useMemo };