Token.java

/*
 * Token.java - Generic token
 * Copyright (C) 1998, 1999 Slava Pestov
 *
 * You may use and modify this package for any purpose. Redistribution is
 * permitted, in both source and binary form, provided that this notice
 * remains intact in all source distributions of this package.
 */
package org.lateralgm.jedit;

/**
 * A linked list of tokens. Each token has three fields - a token
 * identifier, which is a byte value that can be looked up in the
 * array returned by <code>SyntaxDocument.getColors()</code>
 * to get a color value, a length value which is the length of the
 * token in the text, and a pointer to the next token in the list.
 *
 * @author Slava Pestov
 */
public class Token
	{
	/** Normal text token id. This should be used to mark normal text. */
	public static final byte NULL = 0;
	/** Comment 1 token id. This can be used to mark a comment. */
	public static final byte COMMENT1 = 1;
	/** Comment 2 token id. This can be used to mark a comment. */
	public static final byte COMMENT2 = 2;
	/**
	 * Literal 1 token id. This can be used to mark a string literal
	 * (eg, C mode uses this to mark "..." literals)
	 */
	public static final byte LITERAL1 = 3;
	/**
	 * Literal 2 token id. This can be used to mark an object literal
	 * (eg, Java mode uses this to mark true, false, etc)
	 */
	public static final byte LITERAL2 = 4;
	/**
	 * Label token id. This can be used to mark labels
	 * (eg, C mode uses this to mark ...: sequences)
	 */
	public static final byte LABEL = 5;
	/**
	 * Keyword 1 token id. This can be used to mark a keyword.
	 * This should be used for general language constructs.
	 */
	public static final byte KEYWORD1 = 6;
	/**
	 * Keyword 2 token id. This can be used to mark a keyword.
	 * This should be used for preprocessor commands, or variables.
	 */
	public static final byte KEYWORD2 = 7;
	/**
	 * Keyword 3 token id. This can be used to mark a keyword.
	 * This should be used for data types.
	 */
	public static final byte KEYWORD3 = 8;
	/**
	 * Operator token id. This can be used to mark an operator.
	 * (eg, SQL mode marks +, -, etc with this token type)
	 */
	public static final byte OPERATOR = 9;
	/**
	 * Invalid token id. This can be used to mark invalid
	 * or incomplete tokens, so the user can easily spot syntax errors.
	 */
	public static final byte INVALID = 10;
	/** The total number of defined token ids. */
	public static final byte ID_COUNT = 11;
	/** The first id that can be used for internal state in a token marker. */
	public static final byte INTERNAL_FIRST = 100;
	/** The last id that can be used for internal state in a token marker. */
	public static final byte INTERNAL_LAST = 126;
	/** The token type, that along with a length of 0 marks the end of the token list. */
	public static final byte END = 127;
	/** The length of this token. */
	public int length;
	/** The id of this token. */
	public byte id;
	/** The next token in the linked list. */
	public Token next;

	/**
	 * Creates a new token.
	 * @param length The length of the token
	 * @param id The id of the token
	 */
	public Token(int length, byte id)
		{
		this.length = length;
		this.id = id;
		}

	/** Returns a string representation of this token. */
	public String toString()
		{
		return "[id=" + id + ",length=" + length + "]";
		}
	}