code: function decorateRangedError(totalOffset, screenOffset, hexen) {
          var s;
          if (totalOffset === err.offset) {
              accum = 1;
              s = markStart + hexen;
              if (totalOffset === err.endOffset-1) {
                  s += markEnd;
                  accum = 0;
              } else {
                  s = ' ' + s;
              }
              return s;
          } else if (totalOffset === err.endOffset-1) {
              s = hexen + markEnd;
              while (accum-- > 0) s += ' ';
              accum = 0;
              return s;
          } else if (accum) {
              accum += 2;
              return hexen;
          } else {
              return ' ' + hexen + ' ';
          }
      }
docs: TODO: suspected broken across lines, should either test and complete or use some sort of alternate notation such as interstitial lines