Function buildHTML

src/buildHTML.ts:320–411

(tree: AnyParseNode[], options: Options)

 * nodes.
 */
export default function buildHTML(tree: AnyParseNode[], options: Options): DomSpan {
    // Strip off outer tag wrapper for processing below.
    let tag = null;
    if (tree.length === 1 && tree[0].type === "tag") {
        tag = tree[0].tag;
        tree = tree[0].body;
    }

    // Build the expression contained in the tree
    const expression = buildExpression(tree, options, "root");

    let eqnNum;
    if (expression.length === 2 && expression[1].hasClass("tag")) {
        // An environment with automatic equation numbers, e.g. {gather}.
        eqnNum = expression.pop();
    }

    const children = [];

    // Create one base node for each chunk between potential line breaks.
    // The TeXBook [p.173] says "A formula will be broken only after a
    // relation symbol like $=$ or $<$ or $\rightarrow$, or after a binary
    // operation symbol like $+$ or $-$ or $\times$, where the relation or
    // binary operation is on the ``outer level'' of the formula (i.e., not
    // enclosed in {...} and not part of an \over construction)."

    let parts = [];
    for (let i = 0; i < expression.length; i++) {
        parts.push(expression[i]);
        if (expression[i].hasClass("mbin") ||
            expression[i].hasClass("mrel") ||
            expression[i].hasClass("allowbreak")) {
            // Put any post-operator glue on same line as operator.
            // Watch for \nobreak along the way, and stop at \newline.
            let nobreak = false;
            while (i < expression.length - 1 &&
                   expression[i + 1].hasClass("mspace") &&
                   !expression[i + 1].hasClass("newline")) {
                i++;
                parts.push(expression[i]);
                if (expression[i].hasClass("nobreak")) {
                    nobreak = true;
                }
            }
            // Don't allow break if \nobreak among the post-operator glue.
            if (!nobreak) {
                children.push(buildHTMLUnbreakable(parts, options));
                parts = [];
            }
        } else if (expression[i].hasClass("newline")) {
            // Write the line except the newline
            parts.pop();
            if (parts.length > 0) {
                children.push(buildHTMLUnbreakable(parts, options));
                parts = [];
            }
            // Put the newline at the top level
            children.push(expression[i]);