docs/_assets/docsify.js
function genTree (toc, maxLevel) {
  var headlines = [];
  var last = {};

  toc.forEach(function (headline) {
    var level = headline.level || 1;
    var len = level - 1;

    if (level > maxLevel) { return }
    if (last[len]) {
      last[len].children = (last[len].children || []).concat(headline);
    } else {
      headlines.push(headline);
    }
    last[level] = headline;
  });

  return headlines
}
function genTree (toc, maxLevel) {
  var headlines = [];
  var last = {};

  toc.forEach(function (headline) {
    var level = headline.level || 1;
    var len = level - 1;

    if (level > maxLevel) { return }
    if (last[len]) {
      last[len].children = (last[len].children || []).concat(headline);
    } else {
      headlines.push(headline);
    }
    last[level] = headline;
  });

  return headlines
}
function genTree ( toc , maxLevel ) { var headlines = [ ] ; var last = { } ; toc . forEach ( function ( headline ) { var level = headline . level || 1 ; var len = level - 1 ; if ( level > maxLevel ) { return } if ( last [ len ] ) { last [ len ] . children = ( last [ len ] . children || [ ] ) . concat ( headline ) ; } else { headlines . push ( headline ) ; } last [ level ] = headline ; } ) ; return headlines }
gen toc tree
@link https://github.com/killercup/grock/blob/5280ae63e16c5739e9233d9009bc235ed7d79a50/styles/solarized/assets/js/behavior.coffee#L54-L81
@param  {Array} toc
@param  {Number} maxLevel
@return {Array}
gen toc tree