struct Stack(T)
{
    private SList!T container = null;
    private Address pointer = 0;
    private size_t length = 0;
    private string name = null;

    this(string name)
    {
        this.name = name;
    }

    void push(T value)
    {
        this.container.insertFront(value);
        this.pointer++;
        this.length++;
    }

    Nullable!T topSafe()
    {
        Nullable!T front;
        if (this.pointer > 0 && this.length != 0)
            front = this.container.front();
        return front;
    }

    T top()
    {
        auto front_nullable = topSafe();
        if (front_nullable.isNull)
            throw new StackFlowError("The " ~ this.name ~ " stack underflew", this.pointer);
        return front_nullable.get;
    }

    T popTop()
    {
        auto front_nullable = topSafe();
        if (front_nullable.isNull)
            throw new StackFlowError("The " ~ this.name ~ " stack underflew", this.pointer);
        this.container.removeFront();
        this.pointer--;
        this.length--;
        return front_nullable.get;
    }

    Nullable!T nthSafe(size_t n)
    {
        size_t n_prime = 0;
        Nullable!T found;
        foreach (elt; this.container.opSlice())
        {
            if (n_prime++ == n)
            {
                found = elt;
                return found;
            }
        }
        return found;
    }

    T nth(size_t n)
    {
        auto nth_nullable = nthSafe(n);
        if (nth_nullable.isNull)
            throw new StackFlowError("The " ~ this.name ~ " stack overflew", this.pointer);
        return nth_nullable.get;
    }

    T popAtPointer()
    {
        auto nth = nth(this.pointer);
        this.pointer--;
        return nth;
    }

    Address getPointer()
    {
        return this.pointer;
    }

    void setPointer(Address pointer)
    {
        this.pointer = pointer;
    }

    Address getLength()
    {
        return this.length;
    }
}