01: /* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
02: *
03: * The contents of this file are subject to the Netscape Public
04: * License Version 1.1 (the "License"); you may not use this file
05: * except in compliance with the License. You may obtain a copy of
06: * the License at http://www.mozilla.org/NPL/
07: *
08: * Software distributed under the License is distributed on an "AS
09: * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
10: * implied. See the License for the specific language governing
11: * rights and limitations under the License.
12: *
13: * The Original Code is Rhino code, released
14: * May 6, 1999.
15: *
16: * The Initial Developer of the Original Code is Netscape
17: * Communications Corporation. Portions created by Netscape are
18: * Copyright (C) 1997-1999 Netscape Communications Corporation. All
19: * Rights Reserved.
20: *
21: * Contributor(s):
22: * Waldemar Horwat
23: *
24: * Alternatively, the contents of this file may be used under the
25: * terms of the GNU Public License (the "GPL"), in which case the
26: * provisions of the GPL are applicable instead of those above.
27: * If you wish to allow use of your version of this file only
28: * under the terms of the GPL and not to allow others to use your
29: * version of this file under the NPL, indicate your decision by
30: * deleting the provisions above and replace them with the notice
31: * and other provisions required by the GPL. If you do not delete
32: * the provisions above, a recipient may use your version of this
33: * file under either the NPL or the GPL.
34: */
35: // Modified by Google
36: package com.google.gwt.dev.js.rhino;
37:
38: final class BinaryDigitReader {
39: int lgBase; // Logarithm of base of number
40: int digit; // Current digit value in radix given by base
41: int digitPos; // Bit position of last bit extracted from digit
42: String digits; // String containing the digits
43: int start; // Index of the first remaining digit
44: int end; // Index past the last remaining digit
45:
46: BinaryDigitReader(int base, String digits, int start, int end) {
47: lgBase = 0;
48: while (base != 1) {
49: lgBase++;
50: base >>= 1;
51: }
52: digitPos = 0;
53: this .digits = digits;
54: this .start = start;
55: this .end = end;
56: }
57:
58: /* Return the next binary digit from the number or -1 if done */
59: int getNextBinaryDigit() {
60: if (digitPos == 0) {
61: if (start == end)
62: return -1;
63:
64: char c = digits.charAt(start++);
65: if ('0' <= c && c <= '9')
66: digit = c - '0';
67: else if ('a' <= c && c <= 'z')
68: digit = c - 'a' + 10;
69: else
70: digit = c - 'A' + 10;
71: digitPos = lgBase;
72: }
73: return digit >> --digitPos & 1;
74: }
75: }
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