Right now we use codemirror's JavaScript mode on the website but there's a JSX mode now so we should start using that instead.

for (var i = 1, prev = types[0]; i < len - 1; ++i) {
        var type = types[i];
        if (type == "+" && prev == "1" && types[i+1] == "1") types[i] = "1";
        else if (type == "," && prev == types[i+1] &&
                 (prev == "1" || prev == "n")) types[i] = prev;
        prev = type;
      }
      
      
      
      
      for (var i = 0; i < len; ++i) {
        var type = types[i];
        if (type == ",") types[i] = "N";
        else if (type == "%") {
          for (var end = i + 1; end < len && types[end] == "%"; ++end) {}
          var replace = (i && types[i-1] == "!") || (end < len && types[end] == "1") ? "1" : "N";
          for (var j = i; j < end; ++j) types[j] = replace;
          i = end - 1;
        }
      }
      
      
      
      for (var i = 0, cur = outerType; i < len; ++i) {
        var type = types[i];
        if (cur == "L" && type == "1") types[i] = "L";
        else if (isStrong.test(type)) cur = type;
      }