com.google.gwt.dev.js.rhino.BinaryDigitReader Maven / Gradle / Ivy
/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* The contents of this file are subject to the Netscape Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is Rhino code, released
* May 6, 1999.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1997-1999 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
* Waldemar Horwat
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU Public License (the "GPL"), in which case the
* provisions of the GPL are applicable instead of those above.
* If you wish to allow use of your version of this file only
* under the terms of the GPL and not to allow others to use your
* version of this file under the NPL, indicate your decision by
* deleting the provisions above and replace them with the notice
* and other provisions required by the GPL. If you do not delete
* the provisions above, a recipient may use your version of this
* file under either the NPL or the GPL.
*/
// Modified by Google
package com.google.gwt.dev.js.rhino;
final class BinaryDigitReader {
int lgBase; // Logarithm of base of number
int digit; // Current digit value in radix given by base
int digitPos; // Bit position of last bit extracted from digit
String digits; // String containing the digits
int start; // Index of the first remaining digit
int end; // Index past the last remaining digit
BinaryDigitReader(int base, String digits, int start, int end) {
lgBase = 0;
while (base != 1) {
lgBase++;
base >>= 1;
}
digitPos = 0;
this.digits = digits;
this.start = start;
this.end = end;
}
/* Return the next binary digit from the number or -1 if done */
int getNextBinaryDigit()
{
if (digitPos == 0) {
if (start == end)
return -1;
char c = digits.charAt(start++);
if ('0' <= c && c <= '9')
digit = c - '0';
else if ('a' <= c && c <= 'z')
digit = c - 'a' + 10;
else digit = c - 'A' + 10;
digitPos = lgBase;
}
return digit >> --digitPos & 1;
}
}