dotSCAD/docs/lib3x-sort.md

sort

Sorts the elements of a list in ascending order. The list is a list-of-list construct, such as [[a0, a1, a2...], [b0, b1, b2,...], [c0, c1, c2,...],...]. When sorting, the function looks only at one index position of each sublist.

Since: 2.0

Parameters

• lt : The original list.
• by : Can be "x"、"y"、"z", or "idx" (Default). "vt". From dotSCAD 2.3, when by is "vt", it will sort points by zyx (from the last index to the first one). From dotSCAD 3.0, by supports a function literal that compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.
• idx : When by is "idx", the value of idx is used. The Default value is 0.

Examples

use <util/sort.scad>

assert(
    [[2, 0, 0], [5, 0, 0], [7, 0, 0], [9, 0, 0], [10, 0, 0]] == 
    sort([[10, 0, 0], [5, 0, 0], [7, 0, 0], [2, 0, 0], [9, 0, 0]])
);

assert(
    [[2, 0, 0], [5, 0, 0], [7, 0, 0], [9, 0, 0], [10, 0, 0]] == 
    sort([[10, 0, 0], [5, 0, 0], [7, 0, 0], [2, 0, 0], [9, 0, 0]], by = "x")
);

assert(
    [[0, 2, 0], [0, 5, 0], [0, 7, 0], [0, 9, 0], [0, 10, 0]] == 
    sort([[0, 10, 0], [0, 5, 0], [0, 7, 0], [0, 2, 0], [0, 9, 0]], by = "idx", idx = 1)
);

ascending = function(e1, e2) e1 - e2;
descending = function(e1, e2) e2 - e1;
assert(sort([2, 1, 3, 5, 4], by = ascending) == [1, 2, 3, 4, 5]);
assert(sort([2, 1, 3, 5, 4], by = descending) == [5, 4, 3, 2, 1]);