hn job query search

hn_seach.js

function query() {
  var 
    total = 0, shown = 0,
    // HN is done with very unsemantic classes.
    job_list = Array.prototype.slice.call(document.querySelectorAll('.c5a,.c00,.c9c,.cdd,.c73,.c88')),
    query_list = Array.prototype.slice.call(arguments);
    
  // This traverses up the dom stack trying to find a match of a specific class
  function upTo(node, klass) {
    if (node.className === klass) {
      return node;
    } 
    if(node === document.body) {
      throw new Exception();
    }
    return upTo(node.parentNode, klass);
  }

  function style(node, what) {
    upTo(node, 'athing').style.display = what;
  }

  // Turn them all off
  job_list.forEach(function(node) {
    style(node, 'none');
    total ++;
  });

  query_list.forEach(function(query) {
    if (query.forEach) {
      var and_query_list = query.map(function(what) { 
        return what.toLowerCase(); 
      });

      job_list.forEach(function(node) {
        var 
          doesMatch = true, 
          toTest = node.innerHTML.toLowerCase();
          
        and_query_list.forEach(function(query) {
          doesMatch &= (toTest.search(query) > -1);
        })
        
        if(doesMatch) {
          style(node, 'block');
          shown ++;
        }
      });

    } else {
      query = query.toLowerCase();

      job_list.forEach(function(node) {
        if(node.innerHTML.toLowerCase().search(query) !== -1) {
          style(node, 'block');
          shown ++;
        }
      });
    }
  });
  return {shown: shown, total: total}
}