systems.uom.ucum.internal.format.Token Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of systems-ucum Show documentation
Unit System supporting the Unified Code for Units of Measure (UCUM)
There is a newer version: 2.1
/*
 * Units of Measurement Systems
 * Copyright (c) 2005-2017, Jean-Marie Dautelle, Werner Keil and others.
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions
 *    and the following disclaimer in the documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of JSR-363, Units of Measurement nor the names of their contributors may be used to
 *    endorse or promote products derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package systems.uom.ucum.internal.format;

/**
 * Describes the input token stream.
 *
 * @version 0.6, March 15, 2017
 */

public final class Token {

    /**
     * The Serialization identifier for this class. Increment only if the
     * serialized form of the class changes.
     */
    // private static final long serialVersionUID = 2188279658897600591L;

    /**
     * An integer that describes the kind of this token. This numbering system
     * is determined by JavaCCParser, and a table of these numbers is stored in
     * the file ...Constants.java.
     */
    public int kind;

    /** The line number of the first character of this Token. */
    public int beginLine;
    /** The column number of the first character of this Token. */
    public int beginColumn;
    /** The line number of the last character of this Token. */
    public int endLine;
    /** The column number of the last character of this Token. */
    public int endColumn;

    /**
     * The string image of the token.
     */
    public String image;

    /**
     * A reference to the next regular (non-special) token from the input
     * stream. If this is the last token from the input stream, or if the token
     * manager has not read tokens beyond this one, this field is set to null.
     * This is true only if this token is also a regular token. Otherwise, see
     * below for a description of the contents of this field.
     */
    public Token next;

    /**
     * This field is used to access special tokens that occur prior to this
     * token, but after the immediately preceding regular (non-special) token.
     * If there are no such special tokens, this field is set to null. When
     * there are more than one such special token, this field refers to the last
     * of these special tokens, which in turn refers to the next previous
     * special token through its specialToken field, and so on until the first
     * special token (whose specialToken field is null). The next fields of
     * special tokens refer to other special tokens that immediately follow it
     * (without an intervening regular token). If there is no such token, this
     * field is null.
     */
    public Token specialToken;

    /**
     * An optional attribute value of the Token. Tokens which are not used as
     * syntactic sugar will often contain meaningful values that will be used
     * later on by the compiler or interpreter. This attribute value is often
     * different from the image. Any subclass of Token that actually wants to
     * return a non-null value can override this method as appropriate.
     */
    public Object getValue() {
	return null;
    }

    /**
     * No-argument constructor
     */
    public Token() {
    }

    /**
     * Constructs a new token for the specified Image.
     */
    public Token(int kind) {
	this(kind, null);
    }

    /**
     * Constructs a new token for the specified Image and Kind.
     */
    public Token(int kind, String image) {
	this.kind = kind;
	this.image = image;
    }

    /**
     * Returns the image.
     */
    public String toString() {
	return image;
    }

    /**
     * Returns a new Token object, by default. However, if you want, you can
     * create and return subclass objects based on the value of ofKind. Simply
     * add the cases to the switch for all those special cases. For example, if
     * you have a subclass of Token called IDToken that you want to create if
     * ofKind is ID, simply add something like :
     *
     * case MyParserConstants.ID : return new IDToken(ofKind, image);
     *
     * to the following switch statement. Then you can cast matchedToken
     * variable to the appropriate type and use sit in your lexical actions.
     */
    public static Token newToken(int ofKind, String image) {
	switch (ofKind) {
	default:
	    return new Token(ofKind, image);
	}
    }

    public static Token newToken(int ofKind) {
	return newToken(ofKind, null);
    }

}
/*
 * JavaCC - OriginalChecksum=08d08345e10cca30522247698d4478e6 (do not edit this
 * line)
 */