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420 lines
16 KiB
420 lines
16 KiB
import { SelectorType, AttributeAction, } from "./types"; |
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const reName = /^[^\\#]?(?:\\(?:[\da-f]{1,6}\s?|.)|[\w\-\u00b0-\uFFFF])+/; |
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const reEscape = /\\([\da-f]{1,6}\s?|(\s)|.)/gi; |
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const actionTypes = new Map([ |
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[126 /* Tilde */, AttributeAction.Element], |
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[94 /* Circumflex */, AttributeAction.Start], |
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[36 /* Dollar */, AttributeAction.End], |
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[42 /* Asterisk */, AttributeAction.Any], |
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[33 /* ExclamationMark */, AttributeAction.Not], |
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[124 /* Pipe */, AttributeAction.Hyphen], |
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]); |
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// Pseudos, whose data property is parsed as well. |
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const unpackPseudos = new Set([ |
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"has", |
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"not", |
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"matches", |
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"is", |
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"where", |
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"host", |
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"host-context", |
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]); |
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/** |
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* Checks whether a specific selector is a traversal. |
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* This is useful eg. in swapping the order of elements that |
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* are not traversals. |
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* |
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* @param selector Selector to check. |
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*/ |
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export function isTraversal(selector) { |
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switch (selector.type) { |
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case SelectorType.Adjacent: |
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case SelectorType.Child: |
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case SelectorType.Descendant: |
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case SelectorType.Parent: |
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case SelectorType.Sibling: |
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case SelectorType.ColumnCombinator: |
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return true; |
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default: |
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return false; |
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} |
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} |
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const stripQuotesFromPseudos = new Set(["contains", "icontains"]); |
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// Unescape function taken from https://github.com/jquery/sizzle/blob/master/src/sizzle.js#L152 |
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function funescape(_, escaped, escapedWhitespace) { |
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const high = parseInt(escaped, 16) - 0x10000; |
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// NaN means non-codepoint |
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return high !== high || escapedWhitespace |
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? escaped |
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: high < 0 |
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? // BMP codepoint |
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String.fromCharCode(high + 0x10000) |
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: // Supplemental Plane codepoint (surrogate pair) |
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String.fromCharCode((high >> 10) | 0xd800, (high & 0x3ff) | 0xdc00); |
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} |
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function unescapeCSS(str) { |
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return str.replace(reEscape, funescape); |
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} |
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function isQuote(c) { |
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return c === 39 /* SingleQuote */ || c === 34 /* DoubleQuote */; |
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} |
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function isWhitespace(c) { |
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return (c === 32 /* Space */ || |
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c === 9 /* Tab */ || |
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c === 10 /* NewLine */ || |
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c === 12 /* FormFeed */ || |
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c === 13 /* CarriageReturn */); |
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} |
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/** |
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* Parses `selector`, optionally with the passed `options`. |
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* |
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* @param selector Selector to parse. |
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* @param options Options for parsing. |
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* @returns Returns a two-dimensional array. |
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* The first dimension represents selectors separated by commas (eg. `sub1, sub2`), |
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* the second contains the relevant tokens for that selector. |
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*/ |
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export function parse(selector) { |
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const subselects = []; |
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const endIndex = parseSelector(subselects, `${selector}`, 0); |
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if (endIndex < selector.length) { |
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throw new Error(`Unmatched selector: ${selector.slice(endIndex)}`); |
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} |
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return subselects; |
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} |
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function parseSelector(subselects, selector, selectorIndex) { |
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let tokens = []; |
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function getName(offset) { |
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const match = selector.slice(selectorIndex + offset).match(reName); |
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if (!match) { |
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throw new Error(`Expected name, found ${selector.slice(selectorIndex)}`); |
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} |
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const [name] = match; |
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selectorIndex += offset + name.length; |
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return unescapeCSS(name); |
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} |
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function stripWhitespace(offset) { |
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selectorIndex += offset; |
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while (selectorIndex < selector.length && |
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isWhitespace(selector.charCodeAt(selectorIndex))) { |
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selectorIndex++; |
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} |
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} |
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function readValueWithParenthesis() { |
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selectorIndex += 1; |
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const start = selectorIndex; |
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let counter = 1; |
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for (; counter > 0 && selectorIndex < selector.length; selectorIndex++) { |
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if (selector.charCodeAt(selectorIndex) === |
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40 /* LeftParenthesis */ && |
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!isEscaped(selectorIndex)) { |
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counter++; |
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} |
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else if (selector.charCodeAt(selectorIndex) === |
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41 /* RightParenthesis */ && |
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!isEscaped(selectorIndex)) { |
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counter--; |
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} |
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} |
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if (counter) { |
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throw new Error("Parenthesis not matched"); |
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} |
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return unescapeCSS(selector.slice(start, selectorIndex - 1)); |
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} |
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function isEscaped(pos) { |
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let slashCount = 0; |
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while (selector.charCodeAt(--pos) === 92 /* BackSlash */) |
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slashCount++; |
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return (slashCount & 1) === 1; |
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} |
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function ensureNotTraversal() { |
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if (tokens.length > 0 && isTraversal(tokens[tokens.length - 1])) { |
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throw new Error("Did not expect successive traversals."); |
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} |
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} |
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function addTraversal(type) { |
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if (tokens.length > 0 && |
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tokens[tokens.length - 1].type === SelectorType.Descendant) { |
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tokens[tokens.length - 1].type = type; |
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return; |
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} |
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ensureNotTraversal(); |
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tokens.push({ type }); |
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} |
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function addSpecialAttribute(name, action) { |
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tokens.push({ |
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type: SelectorType.Attribute, |
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name, |
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action, |
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value: getName(1), |
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namespace: null, |
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ignoreCase: "quirks", |
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}); |
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} |
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/** |
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* We have finished parsing the current part of the selector. |
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* |
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* Remove descendant tokens at the end if they exist, |
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* and return the last index, so that parsing can be |
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* picked up from here. |
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*/ |
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function finalizeSubselector() { |
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if (tokens.length && |
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tokens[tokens.length - 1].type === SelectorType.Descendant) { |
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tokens.pop(); |
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} |
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if (tokens.length === 0) { |
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throw new Error("Empty sub-selector"); |
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} |
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subselects.push(tokens); |
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} |
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stripWhitespace(0); |
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if (selector.length === selectorIndex) { |
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return selectorIndex; |
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} |
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loop: while (selectorIndex < selector.length) { |
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const firstChar = selector.charCodeAt(selectorIndex); |
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switch (firstChar) { |
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// Whitespace |
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case 32 /* Space */: |
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case 9 /* Tab */: |
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case 10 /* NewLine */: |
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case 12 /* FormFeed */: |
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case 13 /* CarriageReturn */: { |
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if (tokens.length === 0 || |
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tokens[0].type !== SelectorType.Descendant) { |
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ensureNotTraversal(); |
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tokens.push({ type: SelectorType.Descendant }); |
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} |
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stripWhitespace(1); |
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break; |
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} |
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// Traversals |
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case 62 /* GreaterThan */: { |
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addTraversal(SelectorType.Child); |
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stripWhitespace(1); |
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break; |
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} |
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case 60 /* LessThan */: { |
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addTraversal(SelectorType.Parent); |
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stripWhitespace(1); |
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break; |
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} |
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case 126 /* Tilde */: { |
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addTraversal(SelectorType.Sibling); |
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stripWhitespace(1); |
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break; |
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} |
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case 43 /* Plus */: { |
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addTraversal(SelectorType.Adjacent); |
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stripWhitespace(1); |
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break; |
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} |
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// Special attribute selectors: .class, #id |
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case 46 /* Period */: { |
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addSpecialAttribute("class", AttributeAction.Element); |
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break; |
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} |
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case 35 /* Hash */: { |
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addSpecialAttribute("id", AttributeAction.Equals); |
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break; |
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} |
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case 91 /* LeftSquareBracket */: { |
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stripWhitespace(1); |
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// Determine attribute name and namespace |
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let name; |
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let namespace = null; |
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if (selector.charCodeAt(selectorIndex) === 124 /* Pipe */) { |
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// Equivalent to no namespace |
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name = getName(1); |
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} |
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else if (selector.startsWith("*|", selectorIndex)) { |
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namespace = "*"; |
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name = getName(2); |
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} |
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else { |
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name = getName(0); |
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if (selector.charCodeAt(selectorIndex) === 124 /* Pipe */ && |
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selector.charCodeAt(selectorIndex + 1) !== |
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61 /* Equal */) { |
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namespace = name; |
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name = getName(1); |
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} |
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} |
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stripWhitespace(0); |
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// Determine comparison operation |
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let action = AttributeAction.Exists; |
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const possibleAction = actionTypes.get(selector.charCodeAt(selectorIndex)); |
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if (possibleAction) { |
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action = possibleAction; |
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if (selector.charCodeAt(selectorIndex + 1) !== |
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61 /* Equal */) { |
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throw new Error("Expected `=`"); |
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} |
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stripWhitespace(2); |
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} |
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else if (selector.charCodeAt(selectorIndex) === 61 /* Equal */) { |
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action = AttributeAction.Equals; |
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stripWhitespace(1); |
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} |
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// Determine value |
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let value = ""; |
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let ignoreCase = null; |
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if (action !== "exists") { |
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if (isQuote(selector.charCodeAt(selectorIndex))) { |
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const quote = selector.charCodeAt(selectorIndex); |
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let sectionEnd = selectorIndex + 1; |
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while (sectionEnd < selector.length && |
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(selector.charCodeAt(sectionEnd) !== quote || |
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isEscaped(sectionEnd))) { |
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sectionEnd += 1; |
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} |
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if (selector.charCodeAt(sectionEnd) !== quote) { |
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throw new Error("Attribute value didn't end"); |
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} |
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value = unescapeCSS(selector.slice(selectorIndex + 1, sectionEnd)); |
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selectorIndex = sectionEnd + 1; |
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} |
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else { |
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const valueStart = selectorIndex; |
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while (selectorIndex < selector.length && |
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((!isWhitespace(selector.charCodeAt(selectorIndex)) && |
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selector.charCodeAt(selectorIndex) !== |
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93 /* RightSquareBracket */) || |
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isEscaped(selectorIndex))) { |
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selectorIndex += 1; |
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} |
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value = unescapeCSS(selector.slice(valueStart, selectorIndex)); |
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} |
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stripWhitespace(0); |
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// See if we have a force ignore flag |
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const forceIgnore = selector.charCodeAt(selectorIndex) | 0x20; |
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// If the forceIgnore flag is set (either `i` or `s`), use that value |
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if (forceIgnore === 115 /* LowerS */) { |
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ignoreCase = false; |
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stripWhitespace(1); |
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} |
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else if (forceIgnore === 105 /* LowerI */) { |
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ignoreCase = true; |
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stripWhitespace(1); |
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} |
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} |
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if (selector.charCodeAt(selectorIndex) !== |
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93 /* RightSquareBracket */) { |
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throw new Error("Attribute selector didn't terminate"); |
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} |
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selectorIndex += 1; |
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const attributeSelector = { |
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type: SelectorType.Attribute, |
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name, |
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action, |
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value, |
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namespace, |
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ignoreCase, |
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}; |
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tokens.push(attributeSelector); |
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break; |
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} |
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case 58 /* Colon */: { |
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if (selector.charCodeAt(selectorIndex + 1) === 58 /* Colon */) { |
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tokens.push({ |
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type: SelectorType.PseudoElement, |
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name: getName(2).toLowerCase(), |
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data: selector.charCodeAt(selectorIndex) === |
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40 /* LeftParenthesis */ |
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? readValueWithParenthesis() |
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: null, |
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}); |
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continue; |
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} |
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const name = getName(1).toLowerCase(); |
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let data = null; |
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if (selector.charCodeAt(selectorIndex) === |
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40 /* LeftParenthesis */) { |
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if (unpackPseudos.has(name)) { |
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if (isQuote(selector.charCodeAt(selectorIndex + 1))) { |
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throw new Error(`Pseudo-selector ${name} cannot be quoted`); |
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} |
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data = []; |
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selectorIndex = parseSelector(data, selector, selectorIndex + 1); |
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if (selector.charCodeAt(selectorIndex) !== |
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41 /* RightParenthesis */) { |
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throw new Error(`Missing closing parenthesis in :${name} (${selector})`); |
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} |
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selectorIndex += 1; |
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} |
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else { |
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data = readValueWithParenthesis(); |
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if (stripQuotesFromPseudos.has(name)) { |
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const quot = data.charCodeAt(0); |
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if (quot === data.charCodeAt(data.length - 1) && |
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isQuote(quot)) { |
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data = data.slice(1, -1); |
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} |
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} |
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data = unescapeCSS(data); |
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} |
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} |
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tokens.push({ type: SelectorType.Pseudo, name, data }); |
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break; |
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} |
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case 44 /* Comma */: { |
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finalizeSubselector(); |
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tokens = []; |
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stripWhitespace(1); |
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break; |
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} |
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default: { |
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if (selector.startsWith("/*", selectorIndex)) { |
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const endIndex = selector.indexOf("*/", selectorIndex + 2); |
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if (endIndex < 0) { |
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throw new Error("Comment was not terminated"); |
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} |
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selectorIndex = endIndex + 2; |
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// Remove leading whitespace |
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if (tokens.length === 0) { |
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stripWhitespace(0); |
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} |
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break; |
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} |
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let namespace = null; |
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let name; |
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if (firstChar === 42 /* Asterisk */) { |
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selectorIndex += 1; |
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name = "*"; |
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} |
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else if (firstChar === 124 /* Pipe */) { |
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name = ""; |
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if (selector.charCodeAt(selectorIndex + 1) === 124 /* Pipe */) { |
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addTraversal(SelectorType.ColumnCombinator); |
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stripWhitespace(2); |
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break; |
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} |
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} |
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else if (reName.test(selector.slice(selectorIndex))) { |
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name = getName(0); |
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} |
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else { |
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break loop; |
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} |
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if (selector.charCodeAt(selectorIndex) === 124 /* Pipe */ && |
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selector.charCodeAt(selectorIndex + 1) !== 124 /* Pipe */) { |
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namespace = name; |
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if (selector.charCodeAt(selectorIndex + 1) === |
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42 /* Asterisk */) { |
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name = "*"; |
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selectorIndex += 2; |
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} |
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else { |
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name = getName(1); |
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} |
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} |
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tokens.push(name === "*" |
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? { type: SelectorType.Universal, namespace } |
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: { type: SelectorType.Tag, name, namespace }); |
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} |
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} |
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} |
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finalizeSubselector(); |
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return selectorIndex; |
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}
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