808 lines
24 KiB
JavaScript
808 lines
24 KiB
JavaScript
// Copyright 2009 The Closure Library Authors. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS-IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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/**
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* @fileoverview Defines an Integer class for representing (potentially)
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* infinite length two's-complement integer values.
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*
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* For the specific case of 64-bit integers, use goog.math.Long, which is more
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* efficient.
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*
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*/
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goog.provide('goog.math.Integer');
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/**
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* Constructs a two's-complement integer an array containing bits of the
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* integer in 32-bit (signed) pieces, given in little-endian order (i.e.,
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* lowest-order bits in the first piece), and the sign of -1 or 0.
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*
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* See the from* functions below for other convenient ways of constructing
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* Integers.
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*
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* The internal representation of an integer is an array of 32-bit signed
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* pieces, along with a sign (0 or -1) that indicates the contents of all the
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* other 32-bit pieces out to infinity. We use 32-bit pieces because these are
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* the size of integers on which Javascript performs bit-operations. For
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* operations like addition and multiplication, we split each number into 16-bit
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* pieces, which can easily be multiplied within Javascript's floating-point
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* representation without overflow or change in sign.
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*
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* @struct
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* @constructor
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* @param {Array<number>} bits Array containing the bits of the number.
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* @param {number} sign The sign of the number: -1 for negative and 0 positive.
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* @final
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*/
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goog.math.Integer = function(bits, sign) {
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/**
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* @type {!Array<number>}
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* @private
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*/
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this.bits_ = [];
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/**
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* @type {number}
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* @private
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*/
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this.sign_ = sign;
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// Copy the 32-bit signed integer values passed in. We prune out those at the
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// top that equal the sign since they are redundant.
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var top = true;
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for (var i = bits.length - 1; i >= 0; i--) {
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var val = bits[i] | 0;
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if (!top || val != sign) {
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this.bits_[i] = val;
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top = false;
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}
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}
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};
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// NOTE: Common constant values ZERO, ONE, NEG_ONE, etc. are defined below the
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// from* methods on which they depend.
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/**
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* A cache of the Integer representations of small integer values.
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* @type {!Object}
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* @private
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*/
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goog.math.Integer.IntCache_ = {};
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/**
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* Returns an Integer representing the given (32-bit) integer value.
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* @param {number} value A 32-bit integer value.
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* @return {!goog.math.Integer} The corresponding Integer value.
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*/
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goog.math.Integer.fromInt = function(value) {
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if (-128 <= value && value < 128) {
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var cachedObj = goog.math.Integer.IntCache_[value];
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if (cachedObj) {
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return cachedObj;
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}
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}
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var obj = new goog.math.Integer([value | 0], value < 0 ? -1 : 0);
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if (-128 <= value && value < 128) {
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goog.math.Integer.IntCache_[value] = obj;
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}
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return obj;
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};
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/**
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* Returns an Integer representing the given value, provided that it is a finite
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* number. Otherwise, zero is returned.
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* @param {number} value The value in question.
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* @return {!goog.math.Integer} The corresponding Integer value.
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*/
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goog.math.Integer.fromNumber = function(value) {
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if (isNaN(value) || !isFinite(value)) {
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return goog.math.Integer.ZERO;
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} else if (value < 0) {
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return goog.math.Integer.fromNumber(-value).negate();
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} else {
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var bits = [];
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var pow = 1;
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for (var i = 0; value >= pow; i++) {
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bits[i] = (value / pow) | 0;
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pow *= goog.math.Integer.TWO_PWR_32_DBL_;
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}
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return new goog.math.Integer(bits, 0);
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}
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};
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/**
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* Returns a Integer representing the value that comes by concatenating the
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* given entries, each is assumed to be 32 signed bits, given in little-endian
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* order (lowest order bits in the lowest index), and sign-extending the highest
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* order 32-bit value.
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* @param {Array<number>} bits The bits of the number, in 32-bit signed pieces,
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* in little-endian order.
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* @return {!goog.math.Integer} The corresponding Integer value.
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*/
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goog.math.Integer.fromBits = function(bits) {
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var high = bits[bits.length - 1];
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return new goog.math.Integer(bits, high & (1 << 31) ? -1 : 0);
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};
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/**
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* Returns an Integer representation of the given string, written using the
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* given radix.
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* @param {string} str The textual representation of the Integer.
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* @param {number=} opt_radix The radix in which the text is written.
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* @return {!goog.math.Integer} The corresponding Integer value.
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*/
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goog.math.Integer.fromString = function(str, opt_radix) {
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if (str.length == 0) {
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throw Error('number format error: empty string');
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}
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var radix = opt_radix || 10;
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if (radix < 2 || 36 < radix) {
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throw Error('radix out of range: ' + radix);
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}
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if (str.charAt(0) == '-') {
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return goog.math.Integer.fromString(str.substring(1), radix).negate();
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} else if (str.indexOf('-') >= 0) {
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throw Error('number format error: interior "-" character');
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}
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// Do several (8) digits each time through the loop, so as to
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// minimize the calls to the very expensive emulated div.
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var radixToPower = goog.math.Integer.fromNumber(Math.pow(radix, 8));
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var result = goog.math.Integer.ZERO;
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for (var i = 0; i < str.length; i += 8) {
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var size = Math.min(8, str.length - i);
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var value = parseInt(str.substring(i, i + size), radix);
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if (size < 8) {
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var power = goog.math.Integer.fromNumber(Math.pow(radix, size));
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result = result.multiply(power).add(goog.math.Integer.fromNumber(value));
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} else {
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result = result.multiply(radixToPower);
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result = result.add(goog.math.Integer.fromNumber(value));
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}
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}
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return result;
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};
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/**
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* A number used repeatedly in calculations. This must appear before the first
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* call to the from* functions below.
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* @type {number}
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* @private
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*/
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goog.math.Integer.TWO_PWR_32_DBL_ = (1 << 16) * (1 << 16);
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/** @type {!goog.math.Integer} */
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goog.math.Integer.ZERO = goog.math.Integer.fromInt(0);
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/** @type {!goog.math.Integer} */
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goog.math.Integer.ONE = goog.math.Integer.fromInt(1);
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/**
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* @type {!goog.math.Integer}
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* @private
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*/
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goog.math.Integer.TWO_PWR_24_ = goog.math.Integer.fromInt(1 << 24);
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/**
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* Returns the value, assuming it is a 32-bit integer.
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* @return {number} The corresponding int value.
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*/
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goog.math.Integer.prototype.toInt = function() {
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return this.bits_.length > 0 ? this.bits_[0] : this.sign_;
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};
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/** @return {number} The closest floating-point representation to this value. */
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goog.math.Integer.prototype.toNumber = function() {
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if (this.isNegative()) {
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return -this.negate().toNumber();
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} else {
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var val = 0;
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var pow = 1;
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for (var i = 0; i < this.bits_.length; i++) {
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val += this.getBitsUnsigned(i) * pow;
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pow *= goog.math.Integer.TWO_PWR_32_DBL_;
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}
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return val;
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}
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};
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/**
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* @param {number=} opt_radix The radix in which the text should be written.
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* @return {string} The textual representation of this value.
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* @override
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*/
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goog.math.Integer.prototype.toString = function(opt_radix) {
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var radix = opt_radix || 10;
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if (radix < 2 || 36 < radix) {
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throw Error('radix out of range: ' + radix);
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}
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if (this.isZero()) {
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return '0';
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} else if (this.isNegative()) {
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return '-' + this.negate().toString(radix);
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}
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// Do several (6) digits each time through the loop, so as to
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// minimize the calls to the very expensive emulated div.
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var radixToPower = goog.math.Integer.fromNumber(Math.pow(radix, 6));
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var rem = this;
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var result = '';
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while (true) {
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var remDiv = rem.divide(radixToPower);
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// The right shifting fixes negative values in the case when
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// intval >= 2^31; for more details see
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// https://github.com/google/closure-library/pull/498
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var intval = rem.subtract(remDiv.multiply(radixToPower)).toInt() >>> 0;
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var digits = intval.toString(radix);
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rem = remDiv;
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if (rem.isZero()) {
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return digits + result;
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} else {
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while (digits.length < 6) {
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digits = '0' + digits;
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}
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result = '' + digits + result;
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}
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}
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};
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/**
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* Returns the index-th 32-bit (signed) piece of the Integer according to
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* little-endian order (i.e., index 0 contains the smallest bits).
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* @param {number} index The index in question.
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* @return {number} The requested 32-bits as a signed number.
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*/
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goog.math.Integer.prototype.getBits = function(index) {
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if (index < 0) {
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return 0; // Allowing this simplifies bit shifting operations below...
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} else if (index < this.bits_.length) {
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return this.bits_[index];
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} else {
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return this.sign_;
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}
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};
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/**
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* Returns the index-th 32-bit piece as an unsigned number.
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* @param {number} index The index in question.
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* @return {number} The requested 32-bits as an unsigned number.
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*/
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goog.math.Integer.prototype.getBitsUnsigned = function(index) {
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var val = this.getBits(index);
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return val >= 0 ? val : goog.math.Integer.TWO_PWR_32_DBL_ + val;
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};
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/** @return {number} The sign bit of this number, -1 or 0. */
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goog.math.Integer.prototype.getSign = function() {
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return this.sign_;
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};
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/** @return {boolean} Whether this value is zero. */
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goog.math.Integer.prototype.isZero = function() {
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if (this.sign_ != 0) {
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return false;
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}
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for (var i = 0; i < this.bits_.length; i++) {
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if (this.bits_[i] != 0) {
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return false;
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}
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}
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return true;
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};
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/** @return {boolean} Whether this value is negative. */
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goog.math.Integer.prototype.isNegative = function() {
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return this.sign_ == -1;
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};
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/** @return {boolean} Whether this value is odd. */
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goog.math.Integer.prototype.isOdd = function() {
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return (this.bits_.length == 0) && (this.sign_ == -1) ||
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(this.bits_.length > 0) && ((this.bits_[0] & 1) != 0);
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};
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/**
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* @param {goog.math.Integer} other Integer to compare against.
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* @return {boolean} Whether this Integer equals the other.
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*/
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goog.math.Integer.prototype.equals = function(other) {
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if (this.sign_ != other.sign_) {
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return false;
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}
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var len = Math.max(this.bits_.length, other.bits_.length);
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for (var i = 0; i < len; i++) {
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if (this.getBits(i) != other.getBits(i)) {
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return false;
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}
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}
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return true;
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};
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/**
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* @param {goog.math.Integer} other Integer to compare against.
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* @return {boolean} Whether this Integer does not equal the other.
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*/
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goog.math.Integer.prototype.notEquals = function(other) {
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return !this.equals(other);
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};
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/**
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* @param {goog.math.Integer} other Integer to compare against.
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* @return {boolean} Whether this Integer is greater than the other.
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*/
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goog.math.Integer.prototype.greaterThan = function(other) {
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return this.compare(other) > 0;
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};
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/**
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* @param {goog.math.Integer} other Integer to compare against.
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* @return {boolean} Whether this Integer is greater than or equal to the other.
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*/
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goog.math.Integer.prototype.greaterThanOrEqual = function(other) {
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return this.compare(other) >= 0;
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};
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/**
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* @param {goog.math.Integer} other Integer to compare against.
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* @return {boolean} Whether this Integer is less than the other.
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*/
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goog.math.Integer.prototype.lessThan = function(other) {
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return this.compare(other) < 0;
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};
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/**
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* @param {goog.math.Integer} other Integer to compare against.
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* @return {boolean} Whether this Integer is less than or equal to the other.
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*/
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goog.math.Integer.prototype.lessThanOrEqual = function(other) {
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return this.compare(other) <= 0;
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};
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/**
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* Compares this Integer with the given one.
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* @param {goog.math.Integer} other Integer to compare against.
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* @return {number} 0 if they are the same, 1 if the this is greater, and -1
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* if the given one is greater.
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*/
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goog.math.Integer.prototype.compare = function(other) {
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var diff = this.subtract(other);
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if (diff.isNegative()) {
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return -1;
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} else if (diff.isZero()) {
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return 0;
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} else {
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return +1;
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}
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};
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/**
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* Returns an integer with only the first numBits bits of this value, sign
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* extended from the final bit.
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* @param {number} numBits The number of bits by which to shift.
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* @return {!goog.math.Integer} The shorted integer value.
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*/
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goog.math.Integer.prototype.shorten = function(numBits) {
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var arr_index = (numBits - 1) >> 5;
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var bit_index = (numBits - 1) % 32;
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var bits = [];
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for (var i = 0; i < arr_index; i++) {
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bits[i] = this.getBits(i);
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}
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var sigBits = bit_index == 31 ? 0xFFFFFFFF : (1 << (bit_index + 1)) - 1;
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var val = this.getBits(arr_index) & sigBits;
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if (val & (1 << bit_index)) {
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val |= 0xFFFFFFFF - sigBits;
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bits[arr_index] = val;
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return new goog.math.Integer(bits, -1);
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} else {
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bits[arr_index] = val;
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return new goog.math.Integer(bits, 0);
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}
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};
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/** @return {!goog.math.Integer} The negation of this value. */
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goog.math.Integer.prototype.negate = function() {
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return this.not().add(goog.math.Integer.ONE);
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};
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/**
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* Returns the sum of this and the given Integer.
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* @param {goog.math.Integer} other The Integer to add to this.
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* @return {!goog.math.Integer} The Integer result.
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*/
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goog.math.Integer.prototype.add = function(other) {
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var len = Math.max(this.bits_.length, other.bits_.length);
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var arr = [];
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var carry = 0;
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for (var i = 0; i <= len; i++) {
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var a1 = this.getBits(i) >>> 16;
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var a0 = this.getBits(i) & 0xFFFF;
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var b1 = other.getBits(i) >>> 16;
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var b0 = other.getBits(i) & 0xFFFF;
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var c0 = carry + a0 + b0;
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var c1 = (c0 >>> 16) + a1 + b1;
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carry = c1 >>> 16;
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c0 &= 0xFFFF;
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c1 &= 0xFFFF;
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arr[i] = (c1 << 16) | c0;
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}
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return goog.math.Integer.fromBits(arr);
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};
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/**
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* Returns the difference of this and the given Integer.
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* @param {goog.math.Integer} other The Integer to subtract from this.
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* @return {!goog.math.Integer} The Integer result.
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*/
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goog.math.Integer.prototype.subtract = function(other) {
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return this.add(other.negate());
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};
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/**
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* Returns the product of this and the given Integer.
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* @param {goog.math.Integer} other The Integer to multiply against this.
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* @return {!goog.math.Integer} The product of this and the other.
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*/
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goog.math.Integer.prototype.multiply = function(other) {
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if (this.isZero()) {
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return goog.math.Integer.ZERO;
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} else if (other.isZero()) {
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return goog.math.Integer.ZERO;
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}
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if (this.isNegative()) {
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if (other.isNegative()) {
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return this.negate().multiply(other.negate());
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} else {
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return this.negate().multiply(other).negate();
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}
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} else if (other.isNegative()) {
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return this.multiply(other.negate()).negate();
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}
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// If both numbers are small, use float multiplication
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if (this.lessThan(goog.math.Integer.TWO_PWR_24_) &&
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other.lessThan(goog.math.Integer.TWO_PWR_24_)) {
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return goog.math.Integer.fromNumber(this.toNumber() * other.toNumber());
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}
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// Fill in an array of 16-bit products.
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var len = this.bits_.length + other.bits_.length;
|
|
var arr = [];
|
|
for (var i = 0; i < 2 * len; i++) {
|
|
arr[i] = 0;
|
|
}
|
|
for (var i = 0; i < this.bits_.length; i++) {
|
|
for (var j = 0; j < other.bits_.length; j++) {
|
|
var a1 = this.getBits(i) >>> 16;
|
|
var a0 = this.getBits(i) & 0xFFFF;
|
|
|
|
var b1 = other.getBits(j) >>> 16;
|
|
var b0 = other.getBits(j) & 0xFFFF;
|
|
|
|
arr[2 * i + 2 * j] += a0 * b0;
|
|
goog.math.Integer.carry16_(arr, 2 * i + 2 * j);
|
|
arr[2 * i + 2 * j + 1] += a1 * b0;
|
|
goog.math.Integer.carry16_(arr, 2 * i + 2 * j + 1);
|
|
arr[2 * i + 2 * j + 1] += a0 * b1;
|
|
goog.math.Integer.carry16_(arr, 2 * i + 2 * j + 1);
|
|
arr[2 * i + 2 * j + 2] += a1 * b1;
|
|
goog.math.Integer.carry16_(arr, 2 * i + 2 * j + 2);
|
|
}
|
|
}
|
|
|
|
// Combine the 16-bit values into 32-bit values.
|
|
for (var i = 0; i < len; i++) {
|
|
arr[i] = (arr[2 * i + 1] << 16) | arr[2 * i];
|
|
}
|
|
for (var i = len; i < 2 * len; i++) {
|
|
arr[i] = 0;
|
|
}
|
|
return new goog.math.Integer(arr, 0);
|
|
};
|
|
|
|
|
|
/**
|
|
* Carries any overflow from the given index into later entries.
|
|
* @param {Array<number>} bits Array of 16-bit values in little-endian order.
|
|
* @param {number} index The index in question.
|
|
* @private
|
|
*/
|
|
goog.math.Integer.carry16_ = function(bits, index) {
|
|
while ((bits[index] & 0xFFFF) != bits[index]) {
|
|
bits[index + 1] += bits[index] >>> 16;
|
|
bits[index] &= 0xFFFF;
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Returns "this" Integer divided by the given one. Both "this" and the given
|
|
* Integer MUST be positive.
|
|
*
|
|
* This method is only needed for very large numbers (>10^308),
|
|
* for which the original division algorithm gets into an infinite
|
|
* loop (see https://github.com/google/closure-library/issues/500).
|
|
*
|
|
* The algorithm has some possible performance enhancements (or
|
|
* could be rewritten entirely), it's just an initial solution for
|
|
* the issue linked above.
|
|
*
|
|
* @param {!goog.math.Integer} other The Integer to divide "this" by.
|
|
* @return {!goog.math.Integer} "this" value divided by the given one.
|
|
* @private
|
|
*/
|
|
goog.math.Integer.prototype.slowDivide_ = function(other) {
|
|
if (this.isNegative() || other.isNegative()) {
|
|
throw Error('slowDivide_ only works with positive integers.');
|
|
}
|
|
|
|
var twoPower = goog.math.Integer.ONE;
|
|
var multiple = other;
|
|
|
|
// First we have to figure out what the highest bit of the result
|
|
// is, so we increase "twoPower" and "multiple" until "multiple"
|
|
// exceeds "this".
|
|
while (multiple.lessThanOrEqual(this)) {
|
|
twoPower = twoPower.shiftLeft(1);
|
|
multiple = multiple.shiftLeft(1);
|
|
}
|
|
|
|
// Rewind by one power of two, giving us the highest bit of the
|
|
// result.
|
|
var res = twoPower.shiftRight(1);
|
|
var total = multiple.shiftRight(1);
|
|
|
|
// Now we starting decreasing "multiple" and "twoPower" to find the
|
|
// rest of the bits of the result.
|
|
var total2;
|
|
multiple = multiple.shiftRight(2);
|
|
twoPower = twoPower.shiftRight(2);
|
|
while (!multiple.isZero()) {
|
|
// whenever we can add "multiple" to the total and not exceed
|
|
// "this", that means we've found a 1 bit. Else we've found a 0
|
|
// and don't need to add to the result.
|
|
total2 = total.add(multiple);
|
|
if (total2.lessThanOrEqual(this)) {
|
|
res = res.add(twoPower);
|
|
total = total2;
|
|
}
|
|
multiple = multiple.shiftRight(1);
|
|
twoPower = twoPower.shiftRight(1);
|
|
}
|
|
return res;
|
|
};
|
|
|
|
|
|
/**
|
|
* Returns this Integer divided by the given one.
|
|
* @param {!goog.math.Integer} other The Integer to divide this by.
|
|
* @return {!goog.math.Integer} This value divided by the given one.
|
|
*/
|
|
goog.math.Integer.prototype.divide = function(other) {
|
|
if (other.isZero()) {
|
|
throw Error('division by zero');
|
|
} else if (this.isZero()) {
|
|
return goog.math.Integer.ZERO;
|
|
}
|
|
|
|
if (this.isNegative()) {
|
|
if (other.isNegative()) {
|
|
return this.negate().divide(other.negate());
|
|
} else {
|
|
return this.negate().divide(other).negate();
|
|
}
|
|
} else if (other.isNegative()) {
|
|
return this.divide(other.negate()).negate();
|
|
}
|
|
|
|
// Have to degrade to slowDivide for Very Large Numbers, because
|
|
// they're out of range for the floating-point approximation
|
|
// technique used below.
|
|
if (this.bits_.length > 30) {
|
|
return this.slowDivide_(other);
|
|
}
|
|
|
|
// Repeat the following until the remainder is less than other: find a
|
|
// floating-point that approximates remainder / other *from below*, add this
|
|
// into the result, and subtract it from the remainder. It is critical that
|
|
// the approximate value is less than or equal to the real value so that the
|
|
// remainder never becomes negative.
|
|
var res = goog.math.Integer.ZERO;
|
|
var rem = this;
|
|
while (rem.greaterThanOrEqual(other)) {
|
|
// Approximate the result of division. This may be a little greater or
|
|
// smaller than the actual value.
|
|
var approx = Math.max(1, Math.floor(rem.toNumber() / other.toNumber()));
|
|
|
|
// We will tweak the approximate result by changing it in the 48-th digit or
|
|
// the smallest non-fractional digit, whichever is larger.
|
|
var log2 = Math.ceil(Math.log(approx) / Math.LN2);
|
|
var delta = (log2 <= 48) ? 1 : Math.pow(2, log2 - 48);
|
|
|
|
// Decrease the approximation until it is smaller than the remainder. Note
|
|
// that if it is too large, the product overflows and is negative.
|
|
var approxRes = goog.math.Integer.fromNumber(approx);
|
|
var approxRem = approxRes.multiply(other);
|
|
while (approxRem.isNegative() || approxRem.greaterThan(rem)) {
|
|
approx -= delta;
|
|
approxRes = goog.math.Integer.fromNumber(approx);
|
|
approxRem = approxRes.multiply(other);
|
|
}
|
|
|
|
// We know the answer can't be zero... and actually, zero would cause
|
|
// infinite recursion since we would make no progress.
|
|
if (approxRes.isZero()) {
|
|
approxRes = goog.math.Integer.ONE;
|
|
}
|
|
|
|
res = res.add(approxRes);
|
|
rem = rem.subtract(approxRem);
|
|
}
|
|
return res;
|
|
};
|
|
|
|
|
|
/**
|
|
* Returns this Integer modulo the given one.
|
|
* @param {!goog.math.Integer} other The Integer by which to mod.
|
|
* @return {!goog.math.Integer} This value modulo the given one.
|
|
*/
|
|
goog.math.Integer.prototype.modulo = function(other) {
|
|
return this.subtract(this.divide(other).multiply(other));
|
|
};
|
|
|
|
|
|
/** @return {!goog.math.Integer} The bitwise-NOT of this value. */
|
|
goog.math.Integer.prototype.not = function() {
|
|
var len = this.bits_.length;
|
|
var arr = [];
|
|
for (var i = 0; i < len; i++) {
|
|
arr[i] = ~this.bits_[i];
|
|
}
|
|
return new goog.math.Integer(arr, ~this.sign_);
|
|
};
|
|
|
|
|
|
/**
|
|
* Returns the bitwise-AND of this Integer and the given one.
|
|
* @param {goog.math.Integer} other The Integer to AND with this.
|
|
* @return {!goog.math.Integer} The bitwise-AND of this and the other.
|
|
*/
|
|
goog.math.Integer.prototype.and = function(other) {
|
|
var len = Math.max(this.bits_.length, other.bits_.length);
|
|
var arr = [];
|
|
for (var i = 0; i < len; i++) {
|
|
arr[i] = this.getBits(i) & other.getBits(i);
|
|
}
|
|
return new goog.math.Integer(arr, this.sign_ & other.sign_);
|
|
};
|
|
|
|
|
|
/**
|
|
* Returns the bitwise-OR of this Integer and the given one.
|
|
* @param {goog.math.Integer} other The Integer to OR with this.
|
|
* @return {!goog.math.Integer} The bitwise-OR of this and the other.
|
|
*/
|
|
goog.math.Integer.prototype.or = function(other) {
|
|
var len = Math.max(this.bits_.length, other.bits_.length);
|
|
var arr = [];
|
|
for (var i = 0; i < len; i++) {
|
|
arr[i] = this.getBits(i) | other.getBits(i);
|
|
}
|
|
return new goog.math.Integer(arr, this.sign_ | other.sign_);
|
|
};
|
|
|
|
|
|
/**
|
|
* Returns the bitwise-XOR of this Integer and the given one.
|
|
* @param {goog.math.Integer} other The Integer to XOR with this.
|
|
* @return {!goog.math.Integer} The bitwise-XOR of this and the other.
|
|
*/
|
|
goog.math.Integer.prototype.xor = function(other) {
|
|
var len = Math.max(this.bits_.length, other.bits_.length);
|
|
var arr = [];
|
|
for (var i = 0; i < len; i++) {
|
|
arr[i] = this.getBits(i) ^ other.getBits(i);
|
|
}
|
|
return new goog.math.Integer(arr, this.sign_ ^ other.sign_);
|
|
};
|
|
|
|
|
|
/**
|
|
* Returns this value with bits shifted to the left by the given amount.
|
|
* @param {number} numBits The number of bits by which to shift.
|
|
* @return {!goog.math.Integer} This shifted to the left by the given amount.
|
|
*/
|
|
goog.math.Integer.prototype.shiftLeft = function(numBits) {
|
|
var arr_delta = numBits >> 5;
|
|
var bit_delta = numBits % 32;
|
|
var len = this.bits_.length + arr_delta + (bit_delta > 0 ? 1 : 0);
|
|
var arr = [];
|
|
for (var i = 0; i < len; i++) {
|
|
if (bit_delta > 0) {
|
|
arr[i] = (this.getBits(i - arr_delta) << bit_delta) |
|
|
(this.getBits(i - arr_delta - 1) >>> (32 - bit_delta));
|
|
} else {
|
|
arr[i] = this.getBits(i - arr_delta);
|
|
}
|
|
}
|
|
return new goog.math.Integer(arr, this.sign_);
|
|
};
|
|
|
|
|
|
/**
|
|
* Returns this value with bits shifted to the right by the given amount.
|
|
* @param {number} numBits The number of bits by which to shift.
|
|
* @return {!goog.math.Integer} This shifted to the right by the given amount.
|
|
*/
|
|
goog.math.Integer.prototype.shiftRight = function(numBits) {
|
|
var arr_delta = numBits >> 5;
|
|
var bit_delta = numBits % 32;
|
|
var len = this.bits_.length - arr_delta;
|
|
var arr = [];
|
|
for (var i = 0; i < len; i++) {
|
|
if (bit_delta > 0) {
|
|
arr[i] = (this.getBits(i + arr_delta) >>> bit_delta) |
|
|
(this.getBits(i + arr_delta + 1) << (32 - bit_delta));
|
|
} else {
|
|
arr[i] = this.getBits(i + arr_delta);
|
|
}
|
|
}
|
|
return new goog.math.Integer(arr, this.sign_);
|
|
};
|