Function buildExpression

static/katex/katex.mjs:6272–6345

(expression, options, isRealGroup, surrounding)

 * consisting type of nodes that will be added to the left and right.
 */
const buildExpression = function buildExpression(expression, options, isRealGroup, surrounding) {
  if (surrounding === void 0) {
    surrounding = [null, null];
  }

  // Parse expressions into `groups`.
  const groups = [];

  for (let i = 0; i < expression.length; i++) {
    const output = buildGroup(expression[i], options);

    if (output instanceof DocumentFragment) {
      const children = output.children;
      groups.push(...children);
    } else {
      groups.push(output);
    }
  } // If `expression` is a partial group, let the parent handle spacings
  // to avoid processing groups multiple times.


  if (!isRealGroup) {
    return groups;
  }

  let glueOptions = options;

  if (expression.length === 1) {
    const node = checkNodeType(expression[0], "sizing") || checkNodeType(expression[0], "styling");

    if (!node) ; else if (node.type === "sizing") {
      glueOptions = options.havingSize(node.size);
    } else if (node.type === "styling") {
      glueOptions = options.havingStyle(styleMap[node.style]);
    }
  } // Dummy spans for determining spacings between surrounding atoms.
  // If `expression` has no atoms on the left or right, class "leftmost"
  // or "rightmost", respectively, is used to indicate it.


  const dummyPrev = makeSpan$1([surrounding[0] || "leftmost"], [], options);
  const dummyNext = makeSpan$1([surrounding[1] || "rightmost"], [], options); // TODO: These code assumes that a node's math class is the first element
  // of its `classes` array. A later cleanup should ensure this, for
  // instance by changing the signature of `makeSpan`.
  // Before determining what spaces to insert, perform bin cancellation.
  // Binary operators change to ordinary symbols in some contexts.

  traverseNonSpaceNodes(groups, (node, prev) => {
    const prevType = prev.classes[0];
    const type = node.classes[0];

    if (prevType === "mbin" && utils.contains(binRightCanceller, type)) {
      prev.classes[0] = "mord";
    } else if (type === "mbin" && utils.contains(binLeftCanceller, prevType)) {
      node.classes[0] = "mord";
    }
  }, {
    node: dummyPrev