using System;
using System.Collections.Generic;
namespace sharp.parser
{
	public class TokenDefinition
	{
		public String Name { get; private set; }
		public LexerPathSegment[] PathHeads { get { return this.pathHeads.ToArray(); } }

		private List<LexerPathSegment> pathHeads = new List<LexerPathSegment>();

		public TokenDefinition(string name)
		{
			this.Name = name;
		}
		public TokenDefinition(string name,LexerPathSegment pathHead)
		{
			this.Name = name;
			this.pathHeads.Add(pathHead);
		}
		public TokenDefinition(string name,LexerPathSegment[] pathHeads)
		{
			this.Name = name;
            this.pathHeads.AddRange(pathHeads);
		}


		public Token tryParse(CharBuffer buffer){
			int cpos = buffer.Position;

			foreach (LexerPathSegment head in pathHeads){
				int n = head.walk(buffer);
				if (n > 0){
					Token t = new Token(this,buffer,n);
					return t;
				}
			}

			return null;
		}

		public override string ToString()
		{
			return string.Format("[TokenDefinition: Name={0}]", Name);
		}
	}
}