sort.js
2.72 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.isTraversal = void 0;
var css_what_1 = require("css-what");
var procedure = new Map([
[css_what_1.SelectorType.Universal, 50],
[css_what_1.SelectorType.Tag, 30],
[css_what_1.SelectorType.Attribute, 1],
[css_what_1.SelectorType.Pseudo, 0],
]);
function isTraversal(token) {
return !procedure.has(token.type);
}
exports.isTraversal = isTraversal;
var attributes = new Map([
[css_what_1.AttributeAction.Exists, 10],
[css_what_1.AttributeAction.Equals, 8],
[css_what_1.AttributeAction.Not, 7],
[css_what_1.AttributeAction.Start, 6],
[css_what_1.AttributeAction.End, 6],
[css_what_1.AttributeAction.Any, 5],
]);
/**
* Sort the parts of the passed selector,
* as there is potential for optimization
* (some types of selectors are faster than others)
*
* @param arr Selector to sort
*/
function sortByProcedure(arr) {
var procs = arr.map(getProcedure);
for (var i = 1; i < arr.length; i++) {
var procNew = procs[i];
if (procNew < 0)
continue;
for (var j = i - 1; j >= 0 && procNew < procs[j]; j--) {
var token = arr[j + 1];
arr[j + 1] = arr[j];
arr[j] = token;
procs[j + 1] = procs[j];
procs[j] = procNew;
}
}
}
exports.default = sortByProcedure;
function getProcedure(token) {
var _a, _b;
var proc = (_a = procedure.get(token.type)) !== null && _a !== void 0 ? _a : -1;
if (token.type === css_what_1.SelectorType.Attribute) {
proc = (_b = attributes.get(token.action)) !== null && _b !== void 0 ? _b : 4;
if (token.action === css_what_1.AttributeAction.Equals && token.name === "id") {
// Prefer ID selectors (eg. #ID)
proc = 9;
}
if (token.ignoreCase) {
/*
* IgnoreCase adds some overhead, prefer "normal" token
* this is a binary operation, to ensure it's still an int
*/
proc >>= 1;
}
}
else if (token.type === css_what_1.SelectorType.Pseudo) {
if (!token.data) {
proc = 3;
}
else if (token.name === "has" || token.name === "contains") {
proc = 0; // Expensive in any case
}
else if (Array.isArray(token.data)) {
// Eg. :matches, :not
proc = Math.min.apply(Math, token.data.map(function (d) { return Math.min.apply(Math, d.map(getProcedure)); }));
// If we have traversals, try to avoid executing this selector
if (proc < 0) {
proc = 0;
}
}
else {
proc = 2;
}
}
return proc;
}
//# sourceMappingURL=sort.js.map