Method add

src/lualib/Set.ts:34–51

(value: T)

    }

    public add(value: T): Set<T> {
        const isNewValue = !this.has(value);
        if (isNewValue) {
            this.size++;
        }

        // Do order bookkeeping
        if (this.firstKey === undefined) {
            this.firstKey = value;
            this.lastKey = value;
        } else if (isNewValue) {
            this.nextKey.set(this.lastKey!, value);
            this.previousKey.set(value, this.lastKey!);
            this.lastKey = value;
        }

        return this;
    }

    public clear(): void {
        this.nextKey = new LuaTable();