package calculator.model;

import java.util.*;

/**
 * A wrapper around java.util.Stack use to provide stack of Operation objects.
 */
public class OperationStack
{
    /**
     * Add Operation object to the top of stack.
     */
    public void push(Operation operation)
    {
        operationStack.push(operation);
    }

    /**
     * Remove Operation object from the top of stack.
     */
    public Operation pop()
    {
        return (Operation)operationStack.pop();
    }

    /**
     * Returns true if empty.
     */
    public boolean empty()
    {
        return operationStack.empty();
    }

    /**
     * Clear the stack
     */
    public void clear()
    {
        operationStack.clear();
    }

    // The inner stack
    private Stack operationStack = new Stack();
}