Method future

static/katex/katex.mjs:13870–13876

* Returns the topmost token on the stack, without expanding it. * Similar in behavior to TeX's `\futurelet`.

()

  future() {
    if (this.stack.length === 0) {
      this.pushToken(this.lexer.lex());
    }

    return this.stack[this.stack.length - 1];
  }
  /**
   * Remove and return the next unexpanded token.
   */