/*
 * [The "BSD license"]
 *  Copyright (c) 2010 Terence Parr
 *  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. The name of the author may not be used to endorse or promote products
 *      derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 org.antlr.codegen;

public class JavaScriptTarget extends Target {
    
Convert an int to a JavaScript Unicode character literal.
 The current JavaScript spec (ECMA-262) doesn't provide for octal
 notation in String literals, although some implementations support it.
 This method overrides the parent class so that characters will always
 be encoded as Unicode literals (e.g. \u0011).
/** Convert an int to a JavaScript Unicode character literal.
     *
     *  The current JavaScript spec (ECMA-262) doesn't provide for octal
     *  notation in String literals, although some implementations support it.
     *  This method overrides the parent class so that characters will always
     *  be encoded as Unicode literals (e.g. \u0011).
     */
	@Override
    public String encodeIntAsCharEscape(int v) {
        String hex = Integer.toHexString(v|0x10000).substring(1,5);
        return "\\u"+hex;
    }

    
Convert long to two 32-bit numbers separted by a comma.
 JavaScript does not support 64-bit numbers, so we need to break
 the number into two 32-bit literals to give to the Bit.  A number like
 0xHHHHHHHHLLLLLLLL is broken into the following string:
 "0xLLLLLLLL, 0xHHHHHHHH"
 Note that the low order bits are first, followed by the high order bits.
 This is to match how the BitSet constructor works, where the bits are
 passed in in 32-bit chunks with low-order bits coming first.
 Note: stole the following two methods from the ActionScript target.
/** Convert long to two 32-bit numbers separted by a comma.
     *  JavaScript does not support 64-bit numbers, so we need to break
     *  the number into two 32-bit literals to give to the Bit.  A number like
     *  0xHHHHHHHHLLLLLLLL is broken into the following string:
     *  "0xLLLLLLLL, 0xHHHHHHHH"
     *  Note that the low order bits are first, followed by the high order bits.
     *  This is to match how the BitSet constructor works, where the bits are
     *  passed in in 32-bit chunks with low-order bits coming first.
     *
     *  Note: stole the following two methods from the ActionScript target.
     */
	@Override
    public String getTarget64BitStringFromValue(long word) {
        StringBuffer buf = new StringBuffer(22); // enough for the two "0x", "," and " "
        buf.append("0x");
        writeHexWithPadding(buf, Integer.toHexString((int)(word & 0x00000000ffffffffL)));
        buf.append(", 0x");
        writeHexWithPadding(buf, Integer.toHexString((int)(word >> 32)));

        return buf.toString();
    }

    private void writeHexWithPadding(StringBuffer buf, String digits) {
        digits = digits.toUpperCase();
        int padding = 8 - digits.length();
        // pad left with zeros
        for (int i=1; i<=padding; i++) {
            buf.append('0');
        }
        buf.append(digits);
    }
}