BoolConst.java

/*
Copyright (c) 2000 The Regents of the University of California.
All rights reserved.

Permission to use, copy, modify, and distribute this software for any
purpose, without fee, and without written agreement is hereby granted,
provided that the above copyright notice and the following two
paragraphs appear in all copies of this software.

IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*/

import java.io.PrintStream;

/** This clas encapsulates all aspects of code generation for boolean
 * constatns.  String constants and Int constants are handled by
 * StringTable and IntTable respectively, but since there are only two
 * boolean constants, we handle them here. */
class BoolConst {

    private boolean val;

    /** Creates a new boolean constant.
     * @param val the value
     * */
    BoolConst(boolean val) {
        this.val = val;
    }

    /** Creates a new boolean constant.
     * @param val the value
     * */
    BoolConst(Boolean val) {
        this.val = val.booleanValue();
    }

    final static BoolConst truebool = new BoolConst(true);
    final static BoolConst falsebool = new BoolConst(false);

    /** Emits a reference to this boolean constant.
     * @param s the output stream
     * */
    public void codeRef(PrintStream s) {
        s.print(CgenSupport.BOOLCONST_PREFIX + (val ? "1" : "0"));
    }

    /** Generates code for the boolean constant definition.  This method
     * is incomplete; you get to finish it up in programming assignment
     * 5.
     * @param boolclasstag the class tag for string object
     * @param s the output stream
     *
     * */
    public void codeDef(int boolclasstag, PrintStream s) {
        codeRef(s); s.print(CgenSupport.LABEL); // label
        s.println(CgenSupport.WORD + boolclasstag); // tag
        s.println(CgenSupport.WORD + (CgenSupport.DEFAULT_OBJFIELDS + CgenSupport.BOOL_SLOTS)); // size
        s.print(CgenSupport.WORD);
        /* Add code to reference the dispatch table for class Bool here */
        s.println("");        // dispatch table
        s.println(CgenSupport.WORD + (val ? "1" : "0")); // value (0 or 1)
    }

}