Class Namespace

static/katex/katex.mjs:12903–13021

* A `Namespace` refers to a space of nameable things like macros or lengths, * which can be `set` either globally or local to a nested group, using an * undo stack similar to how TeX implements this functionality. * Performance-wise, `get` and local `set` take constant time, while global * `set`

 * `set` takes time proportional to the depth of group nesting.
 */
class Namespace {
  /**
   * Both arguments are optional.  The first argument is an object of
   * built-in mappings which never change.  The second argument is an object
   * of initial (global-level) mappings, which will constantly change
   * according to any global/top-level `set`s done.
   */
  constructor(builtins, globalMacros) {
    if (builtins === void 0) {
      builtins = {};
    }

    if (globalMacros === void 0) {
      globalMacros = {};
    }

    this.current = void 0;
    this.builtins = void 0;
    this.undefStack = void 0;
    this.current = globalMacros;
    this.builtins = builtins;
    this.undefStack = [];
  }
  /**
   * Start a new nested group, affecting future local `set`s.
   */


  beginGroup() {
    this.undefStack.push({});
  }
  /**
   * End current nested group, restoring values before the group began.
   */


  endGroup() {
    if (this.undefStack.length === 0) {
      throw new ParseError("Unbalanced namespace destruction: attempt " + "to pop global namespace; please report this as a bug");
    }

    const undefs = this.undefStack.pop();

    for (const undef in undefs) {
      if (undefs.hasOwnProperty(undef)) {
        if (undefs[undef] === undefined) {
          delete this.current[undef];
        } else {
          this.current[undef] = undefs[undef];
        }
      }
    }
  }
  /**
   * Detect whether `name` has a definition.  Equivalent to
   * `get(name) != null`.
   */