//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//     file="TokenNodeStack.cs"
//     Project: StgSharp
//     AuthorGroup: Nitload Space
//     Copyright (c) Nitload Space. All rights reserved.
//     
//     Permission is hereby granted, free of charge, to any person 
//     obtaining a copy of this software and associated documentation 
//     files (the “Software”), to deal in the Software without restriction, 
//     including without limitation the rights to use, copy, modify, merge,
//     publish, distribute, sublicense, and/or sell copies of the Software, 
//     and to permit persons to whom the Software is furnished to do so, 
//     subject to the following conditions:
//     
//     The above copyright notice and 
//     this permission notice shall be included in all copies 
//     or substantial portions of the Software.
//     
//     THE SOFTWARE IS PROVIDED “AS IS”, 
//     WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
//     INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
//     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
//     IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
//     DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
//     ARISING FROM, OUT OF OR IN CONNECTION WITH 
//     THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//     
//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;

namespace StgSharp.Script
{
    public class TokenNodeStack<TNode, TType>
        where TNode: IASTNode<TNode, TType>
        where TType: ITypeSource<TType>
    {

        private Stack<bool> _isNode;

        private Stack<TNode> _nodes;
        private Stack<Token> _tokens;

        public TokenNodeStack()
        {
            _nodes = new Stack<TNode>( 4 );
            _tokens = new Stack<Token>( 4 );
            _isNode = new Stack<bool>( 8 );
        }

        public int Count => _isNode.Count;

        public bool Peek( out Token t, TNode n )
        {
            if( _isNode.Peek() ) {
                n = _nodes.Peek();
                t = Token.Empty;
                return true;
            } else {
                t = _tokens.Peek();
                n = TNode.Empty;
                return false;
            }
        }

        public bool Pop( out Token t, out TNode n )
        {
            if( _isNode.Pop() ) {
                n = _nodes.Pop();
                t = Token.Empty;
                return true;
            } else {
                t = _tokens.Pop();
                n = TNode.Empty;
                return false;
            }
        }

        public void Push( TNode node )
        {
            _nodes.Push( node );
            _isNode.Push( true );
        }

        public void Push( Token token )
        {
            _tokens.Push( token );
            _isNode.Push( false );
        }

    }
}