JezK
Edit File: toint32.js
// Copyright 2008 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * 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. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "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 COPYRIGHT // OWNER OR CONTRIBUTORS 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. function toInt32(x) { return x | 0; } assertEquals(0, toInt32(Infinity), "Inf"); assertEquals(0, toInt32(-Infinity), "-Inf"); assertEquals(0, toInt32(NaN), "NaN"); assertEquals(0, toInt32(0.0), "zero"); assertEquals(0, toInt32(-0.0), "-zero"); assertEquals(0, toInt32(Number.MIN_VALUE)); assertEquals(0, toInt32(-Number.MIN_VALUE)); assertEquals(0, toInt32(0.1)); assertEquals(0, toInt32(-0.1)); assertEquals(1, toInt32(1), "one"); assertEquals(1, toInt32(1.1), "onepointone"); assertEquals(-1, toInt32(-1), "-one"); assertEquals(0, toInt32(0.6), "truncate positive (0.6)"); assertEquals(1, toInt32(1.6), "truncate positive (1.6)"); assertEquals(0, toInt32(-0.6), "truncate negative (-0.6)"); assertEquals(-1, toInt32(-1.6), "truncate negative (-1.6)"); assertEquals(2147483647, toInt32(2147483647)); assertEquals(-2147483648, toInt32(2147483648)); assertEquals(-2147483647, toInt32(2147483649)); assertEquals(-1, toInt32(4294967295)); assertEquals(0, toInt32(4294967296)); assertEquals(1, toInt32(4294967297)); assertEquals(-2147483647, toInt32(-2147483647)); assertEquals(-2147483648, toInt32(-2147483648)); assertEquals(2147483647, toInt32(-2147483649)); assertEquals(1, toInt32(-4294967295)); assertEquals(0, toInt32(-4294967296)); assertEquals(-1, toInt32(-4294967297)); assertEquals(-2147483648, toInt32(2147483648.25)); assertEquals(-2147483648, toInt32(2147483648.5)); assertEquals(-2147483648, toInt32(2147483648.75)); assertEquals(-1, toInt32(4294967295.25)); assertEquals(-1, toInt32(4294967295.5)); assertEquals(-1, toInt32(4294967295.75)); assertEquals(-1294967296, toInt32(3000000000.25)); assertEquals(-1294967296, toInt32(3000000000.5)); assertEquals(-1294967296, toInt32(3000000000.75)); assertEquals(-2147483648, toInt32(-2147483648.25)); assertEquals(-2147483648, toInt32(-2147483648.5)); assertEquals(-2147483648, toInt32(-2147483648.75)); assertEquals(1, toInt32(-4294967295.25)); assertEquals(1, toInt32(-4294967295.5)); assertEquals(1, toInt32(-4294967295.75)); assertEquals(1294967296, toInt32(-3000000000.25)); assertEquals(1294967296, toInt32(-3000000000.5)); assertEquals(1294967296, toInt32(-3000000000.75)); var base = Math.pow(2, 64); assertEquals(0, toInt32(base + 0)); assertEquals(0, toInt32(base + 1117)); assertEquals(4096, toInt32(base + 2234)); assertEquals(4096, toInt32(base + 3351)); assertEquals(4096, toInt32(base + 4468)); assertEquals(4096, toInt32(base + 5585)); assertEquals(8192, toInt32(base + 6702)); assertEquals(8192, toInt32(base + 7819)); assertEquals(8192, toInt32(base + 8936)); assertEquals(8192, toInt32(base + 10053)); assertEquals(12288, toInt32(base + 11170)); assertEquals(12288, toInt32(base + 12287)); assertEquals(12288, toInt32(base + 13404)); assertEquals(16384, toInt32(base + 14521)); assertEquals(16384, toInt32(base + 15638)); assertEquals(16384, toInt32(base + 16755)); assertEquals(16384, toInt32(base + 17872)); assertEquals(20480, toInt32(base + 18989)); assertEquals(20480, toInt32(base + 20106)); assertEquals(20480, toInt32(base + 21223)); assertEquals(20480, toInt32(base + 22340)); assertEquals(24576, toInt32(base + 23457)); assertEquals(24576, toInt32(base + 24574)); assertEquals(24576, toInt32(base + 25691)); assertEquals(28672, toInt32(base + 26808)); assertEquals(28672, toInt32(base + 27925)); assertEquals(28672, toInt32(base + 29042)); assertEquals(28672, toInt32(base + 30159)); assertEquals(32768, toInt32(base + 31276)); // bignum is (2^53 - 1) * 2^31 - highest number with bit 31 set. var bignum = Math.pow(2, 84) - Math.pow(2, 31); assertEquals(-Math.pow(2,31), toInt32(bignum)); assertEquals(-Math.pow(2,31), toInt32(-bignum)); assertEquals(0, toInt32(2 * bignum)); assertEquals(0, toInt32(-(2 * bignum))); assertEquals(0, toInt32(bignum - Math.pow(2,31))); assertEquals(0, toInt32(-(bignum - Math.pow(2,31)))); // max_fraction is largest number below 1. var max_fraction = (1 - Math.pow(2,-53)); assertEquals(0, toInt32(max_fraction)); assertEquals(0, toInt32(-max_fraction));