245 lines
6.7 KiB
JavaScript
245 lines
6.7 KiB
JavaScript
import katex from '../katex.mjs';
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/* eslint no-constant-condition:0 */
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var findEndOfMath = function findEndOfMath(delimiter, text, startIndex) {
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// Adapted from
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// https://github.com/Khan/perseus/blob/master/src/perseus-markdown.jsx
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var index = startIndex;
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var braceLevel = 0;
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var delimLength = delimiter.length;
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while (index < text.length) {
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var character = text[index];
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if (braceLevel <= 0 && text.slice(index, index + delimLength) === delimiter) {
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return index;
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} else if (character === "\\") {
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index++;
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} else if (character === "{") {
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braceLevel++;
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} else if (character === "}") {
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braceLevel--;
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}
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index++;
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}
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return -1;
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};
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var escapeRegex = function escapeRegex(string) {
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return string.replace(/[-/\\^$*+?.()|[\]{}]/g, "\\$&");
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};
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var amsRegex = /^\\begin{/;
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var splitAtDelimiters = function splitAtDelimiters(text, delimiters) {
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var index;
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var data = [];
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var regexLeft = new RegExp("(" + delimiters.map(x => escapeRegex(x.left)).join("|") + ")");
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while (true) {
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index = text.search(regexLeft);
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if (index === -1) {
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break;
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}
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if (index > 0) {
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data.push({
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type: "text",
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data: text.slice(0, index)
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});
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text = text.slice(index); // now text starts with delimiter
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} // ... so this always succeeds:
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var i = delimiters.findIndex(delim => text.startsWith(delim.left));
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index = findEndOfMath(delimiters[i].right, text, delimiters[i].left.length);
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if (index === -1) {
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break;
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}
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var rawData = text.slice(0, index + delimiters[i].right.length);
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var math = amsRegex.test(rawData) ? rawData : text.slice(delimiters[i].left.length, index);
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data.push({
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type: "math",
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data: math,
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rawData,
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display: delimiters[i].display
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});
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text = text.slice(index + delimiters[i].right.length);
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}
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if (text !== "") {
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data.push({
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type: "text",
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data: text
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});
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}
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return data;
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};
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/* eslint no-console:0 */
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/* Note: optionsCopy is mutated by this method. If it is ever exposed in the
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* API, we should copy it before mutating.
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*/
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var renderMathInText = function renderMathInText(text, optionsCopy) {
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var data = splitAtDelimiters(text, optionsCopy.delimiters);
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if (data.length === 1 && data[0].type === 'text') {
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// There is no formula in the text.
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// Let's return null which means there is no need to replace
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// the current text node with a new one.
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return null;
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}
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var fragment = document.createDocumentFragment();
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for (var i = 0; i < data.length; i++) {
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if (data[i].type === "text") {
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fragment.appendChild(document.createTextNode(data[i].data));
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} else {
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var span = document.createElement("span");
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var math = data[i].data; // Override any display mode defined in the settings with that
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// defined by the text itself
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optionsCopy.displayMode = data[i].display;
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try {
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if (optionsCopy.preProcess) {
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math = optionsCopy.preProcess(math);
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}
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katex.render(math, span, optionsCopy);
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} catch (e) {
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if (!(e instanceof katex.ParseError)) {
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throw e;
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}
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optionsCopy.errorCallback("KaTeX auto-render: Failed to parse `" + data[i].data + "` with ", e);
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fragment.appendChild(document.createTextNode(data[i].rawData));
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continue;
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}
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fragment.appendChild(span);
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}
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}
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return fragment;
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};
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var renderElem = function renderElem(elem, optionsCopy) {
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for (var i = 0; i < elem.childNodes.length; i++) {
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var childNode = elem.childNodes[i];
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if (childNode.nodeType === 3) {
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// Text node
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// Concatenate all sibling text nodes.
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// Webkit browsers split very large text nodes into smaller ones,
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// so the delimiters may be split across different nodes.
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var textContentConcat = childNode.textContent;
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var sibling = childNode.nextSibling;
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var nSiblings = 0;
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while (sibling && sibling.nodeType === Node.TEXT_NODE) {
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textContentConcat += sibling.textContent;
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sibling = sibling.nextSibling;
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nSiblings++;
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}
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var frag = renderMathInText(textContentConcat, optionsCopy);
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if (frag) {
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// Remove extra text nodes
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for (var j = 0; j < nSiblings; j++) {
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childNode.nextSibling.remove();
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}
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i += frag.childNodes.length - 1;
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elem.replaceChild(frag, childNode);
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} else {
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// If the concatenated text does not contain math
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// the siblings will not either
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i += nSiblings;
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}
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} else if (childNode.nodeType === 1) {
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(function () {
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// Element node
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var className = ' ' + childNode.className + ' ';
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var shouldRender = optionsCopy.ignoredTags.indexOf(childNode.nodeName.toLowerCase()) === -1 && optionsCopy.ignoredClasses.every(x => className.indexOf(' ' + x + ' ') === -1);
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if (shouldRender) {
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renderElem(childNode, optionsCopy);
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}
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})();
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} // Otherwise, it's something else, and ignore it.
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}
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};
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var renderMathInElement = function renderMathInElement(elem, options) {
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if (!elem) {
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throw new Error("No element provided to render");
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}
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var optionsCopy = {}; // Object.assign(optionsCopy, option)
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for (var option in options) {
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if (options.hasOwnProperty(option)) {
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optionsCopy[option] = options[option];
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}
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} // default options
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optionsCopy.delimiters = optionsCopy.delimiters || [{
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left: "$$",
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right: "$$",
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display: true
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}, {
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left: "\\(",
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right: "\\)",
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display: false
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}, // LaTeX uses $…$, but it ruins the display of normal `$` in text:
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// {left: "$", right: "$", display: false},
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// $ must come after $$
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// Render AMS environments even if outside $$…$$ delimiters.
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{
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left: "\\begin{equation}",
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right: "\\end{equation}",
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display: true
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}, {
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left: "\\begin{align}",
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right: "\\end{align}",
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display: true
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}, {
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left: "\\begin{alignat}",
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right: "\\end{alignat}",
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display: true
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}, {
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left: "\\begin{gather}",
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right: "\\end{gather}",
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display: true
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}, {
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left: "\\begin{CD}",
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right: "\\end{CD}",
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display: true
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}, {
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left: "\\[",
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right: "\\]",
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display: true
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}];
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optionsCopy.ignoredTags = optionsCopy.ignoredTags || ["script", "noscript", "style", "textarea", "pre", "code", "option"];
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optionsCopy.ignoredClasses = optionsCopy.ignoredClasses || [];
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optionsCopy.errorCallback = optionsCopy.errorCallback || console.error; // Enable sharing of global macros defined via `\gdef` between different
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// math elements within a single call to `renderMathInElement`.
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optionsCopy.macros = optionsCopy.macros || {};
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renderElem(elem, optionsCopy);
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};
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export { renderMathInElement as default };
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