2 * (C) Copyright 2004-2007 Shawn Betts
3 * (C) Copyright 2007-2010 John J. Foerch
4 * (C) Copyright 2007-2008 Jeremy Maitin-Shepard
6 * Use, modification, and distribution are subject to the terms specified in the
13 * remove_duplicates_filter returns a function that can be used in
14 * Array.filter. It removes duplicates. Optional argument cmp is a
15 * comparison function to test equality. The default comparison function
16 * tests equality of the string representation of the objects, making it
17 * unsuitable for use filtering a list of objects of compound data types.
19 function remove_duplicates_filter (cmp) {
23 if (acc.some(function (y) cmp(x, y)))
31 if (acc[x]) return false;
39 * Given an array, switches places on the subarrays at index i1 to i2 and j1 to
40 * j2. Leaves the rest of the array unchanged.
42 function switch_subarrays (arr, i1, i2, j1, j2) {
43 return arr.slice(0, i1) +
47 arr.slice(j2, arr.length);
52 * splice_ranges: Given an ordered array of non-overlapping ranges,
53 * represented as elements of [start, end], insert a new range into the
54 * array, extending, replacing, or merging existing ranges as needed.
55 * Mutates `arr' in place, but returns the reference to it.
59 * splice_range([[1,3],[4,6], 5, 8)
62 * splice_range([[1,3],[4,6],[7,10]], 2, 8)
65 function splice_range (arr, start, end) {
66 for (var i = 0; i < arr.length; ++i) {
71 arr.splice(i, 0, [start, end]);
79 * The range we are inserting overlaps the current
80 * range. We need to scan right to see if it also contains any other
81 * ranges entirely, and remove them if necessary.
84 while (j < arr.length && end >= arr[j][0])
87 arr[i][1] = Math.max(end, arr[j][1]);
88 arr.splice(i + 1, j - i);
92 if (start > arr[arr.length - 1][1])
93 arr.push([start, end]);