// Loads a csv file cross-domain from anywhere via Yahoo! Pipes
function load_csv(url, cb, opts) {
  function format(raw) {
    // Y| rows are listed as objects with col_1, ... col_n properties; arrayify
    function rollup(row) {
      for (var c = 1, col, arr = []; row.hasOwnProperty(col = 'col_'+ c); c++)
        arr.push(row[col]);
      return col_cb ? arr.map(col_cb) : arr;
    }
    function object(arr) {
      function stow(val, idx) { data[headers[idx]] = val; }
      var data = {};
      arr.forEach(stow);
      return data;
    }
  
    var col_cb  = opts.header_cb
      , headers = rollup(raw.value.items[0]);
    col_cb = opts.line_cb;
    return raw.value.items.slice(1).map(rollup).map(object);
  }

  var pipe = 'a1aa6137151bc86851b7b65373f95bce'
    , nth  = load_csv.nth = (load_csv.nth || 0) + 1
    , name = 'cb' + nth.toString(36)
    , skip = encodeURIComponent(opts.skip_lines || 0)
    , head = encodeURIComponent(opts.hdr_line_no || 0)
    , purl = 'http://pipes.yahoo.com/pipes/pipe.run?_id='+ pipe
           + '&_render=json&_callback=load_csv.' + name
           + '&u=' + encodeURIComponent(url) +'&x='+ skip +'&c='+ head
    , load = document.createElement('script');

  load_csv[name] = function(json) {
    delete load_csv[name];
    document.head.removeChild(load);
    cb(format(json));
  };

  load.src = purl;
  document.head.appendChild(load);
}