export function memoize<A extends object, B>(fn: (a: A) => B, cacheResultAsKey = false, cache: WeakMap<A, B> = new WeakMap()): (a: A) => B {
    return function(arg) {
        if (arg == null) {
            return fn(arg);
        }
        // try {
        let result = cache.get(arg);
        if (result === undefined) {
            cache.set(arg, result = fn(arg));
            if (cacheResultAsKey) {
                cache.set(result as any as A, result);
            }
        }
        return result;
        // }
        // catch(e) {
        //     console.log("Error: " + arg);
        //     throw e;
        // }
    }
}