Mon, 17 Apr 2017 11:46:11 -0700
Added tag jdk8u141-b05 for changeset f7fc5fc0e2cb
aoqi@0 | 1 | #// Usage: jjs -scripting -cp . jsobject_mapreduce.js |
aoqi@0 | 2 | |
aoqi@0 | 3 | /* |
aoqi@0 | 4 | * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. |
attila@962 | 5 | * |
aoqi@0 | 6 | * Redistribution and use in source and binary forms, with or without |
aoqi@0 | 7 | * modification, are permitted provided that the following conditions |
aoqi@0 | 8 | * are met: |
attila@962 | 9 | * |
aoqi@0 | 10 | * - Redistributions of source code must retain the above copyright |
aoqi@0 | 11 | * notice, this list of conditions and the following disclaimer. |
attila@962 | 12 | * |
aoqi@0 | 13 | * - Redistributions in binary form must reproduce the above copyright |
aoqi@0 | 14 | * notice, this list of conditions and the following disclaimer in the |
aoqi@0 | 15 | * documentation and/or other materials provided with the distribution. |
attila@962 | 16 | * |
aoqi@0 | 17 | * - Neither the name of Oracle nor the names of its |
aoqi@0 | 18 | * contributors may be used to endorse or promote products derived |
aoqi@0 | 19 | * from this software without specific prior written permission. |
attila@962 | 20 | * |
aoqi@0 | 21 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS |
aoqi@0 | 22 | * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
aoqi@0 | 23 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
aoqi@0 | 24 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
aoqi@0 | 25 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
aoqi@0 | 26 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
aoqi@0 | 27 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
aoqi@0 | 28 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
aoqi@0 | 29 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
aoqi@0 | 30 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
aoqi@0 | 31 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
aoqi@0 | 32 | */ |
aoqi@0 | 33 | |
attila@962 | 34 | // Many Array.prototype functions such as map, |
aoqi@0 | 35 | // filter, reduce, reduceRight, every, some are generic. |
attila@962 | 36 | // These functions accept ECMAScript array as well as |
aoqi@0 | 37 | // many array-like objects including JSObjects. |
aoqi@0 | 38 | // See also http://en.wikipedia.org/wiki/MapReduce |
aoqi@0 | 39 | |
aoqi@0 | 40 | `javac BufferArray.java`; |
aoqi@0 | 41 | |
aoqi@0 | 42 | var BufferArray = Java.type("BufferArray"); |
aoqi@0 | 43 | var buf = new BufferArray(10); |
aoqi@0 | 44 | |
aoqi@0 | 45 | var map = Array.prototype.map; |
aoqi@0 | 46 | var filter = Array.prototype.filter; |
aoqi@0 | 47 | var reduce = Array.prototype.reduce; |
aoqi@0 | 48 | |
aoqi@0 | 49 | // make random list of numbers |
aoqi@0 | 50 | for (var i = 0; i < 10; i++) |
aoqi@0 | 51 | buf[i] = Math.random(); |
aoqi@0 | 52 | |
aoqi@0 | 53 | var forEach = Array.prototype.forEach; |
aoqi@0 | 54 | // print numbers in the list |
aoqi@0 | 55 | forEach.call(buf, function(x) print(x)); |
aoqi@0 | 56 | |
aoqi@0 | 57 | // print sum of squares of the random numbers |
aoqi@0 | 58 | print("Square sum:", |
aoqi@0 | 59 | reduce.call( |
attila@962 | 60 | map.call(buf, function(x) x*x), |
aoqi@0 | 61 | function(x, y) x + y) |
aoqi@0 | 62 | ); |