code: function skipMarker(state, line) {
      var pos, marker,
          start = state.bMarks[line] + state.tShift[line],
          max = state.eMarks[line];
  
      if (start >= max) { return -1; }
  
      // Check bullet
      marker = state.src.charCodeAt(start++);
      if (marker !== 0x7E/* ~ */ && marker !== 0x3A/* : */) { return -1; }
  
      pos = state.skipSpaces(start);
  
      // require space after ":"
      if (start === pos) { return -1; }
  
      // no empty definitions, e.g. "  : "
      if (pos >= max) { return -1; }
  
      return start;
    }
docs: Search `[:~][\n ]`, returns next pos after marker on success or -1 on fail.