79 lines
No EOL
2.4 KiB
JavaScript
79 lines
No EOL
2.4 KiB
JavaScript
import { AttributeAction, SelectorType } from "css-what";
|
|
const procedure = new Map([
|
|
[SelectorType.Universal, 50],
|
|
[SelectorType.Tag, 30],
|
|
[SelectorType.Attribute, 1],
|
|
[SelectorType.Pseudo, 0],
|
|
]);
|
|
export function isTraversal(token) {
|
|
return !procedure.has(token.type);
|
|
}
|
|
const attributes = new Map([
|
|
[AttributeAction.Exists, 10],
|
|
[AttributeAction.Equals, 8],
|
|
[AttributeAction.Not, 7],
|
|
[AttributeAction.Start, 6],
|
|
[AttributeAction.End, 6],
|
|
[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
|
|
*/
|
|
export default function sortByProcedure(arr) {
|
|
const procs = arr.map(getProcedure);
|
|
for (let i = 1; i < arr.length; i++) {
|
|
const procNew = procs[i];
|
|
if (procNew < 0)
|
|
continue;
|
|
for (let j = i - 1; j >= 0 && procNew < procs[j]; j--) {
|
|
const token = arr[j + 1];
|
|
arr[j + 1] = arr[j];
|
|
arr[j] = token;
|
|
procs[j + 1] = procs[j];
|
|
procs[j] = procNew;
|
|
}
|
|
}
|
|
}
|
|
function getProcedure(token) {
|
|
var _a, _b;
|
|
let proc = (_a = procedure.get(token.type)) !== null && _a !== void 0 ? _a : -1;
|
|
if (token.type === SelectorType.Attribute) {
|
|
proc = (_b = attributes.get(token.action)) !== null && _b !== void 0 ? _b : 4;
|
|
if (token.action === 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 === 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(...token.data.map((d) => Math.min(...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
|