import Prim "mo:prim";
import Buffer "buffer";

module {
    public class Stack<T>() {
        let buffer = Buffer.Buffer<T>(0);

        public func isEmpty() : Bool {
            buffer.size() == 0;
        };

        public func push(value : T) {
            buffer.add(value);
        };

        public func pop() : T {
            switch (buffer.removeLast()) {
                case (?value) value;
                case _ Prim.trap("empty");
            };
        };
    };
};