code: function nextLine() {
              if (stream) {
                  curOffset++; // account for \n
                  if (curOffset >= length) {
                      return false;
                  }
              }
              lineStart = curOffset;
              var lineEnd = text.indexOf("\n", lineStart);
              if (lineEnd === -1) {
                  lineEnd = length;
              }
              stream = new CodeMirror.StringStream(text.slice(curOffset, lineEnd));
              return true;
          }
docs: Get a stream for the next line, and update curOffset and lineStart to point to the beginning of that next line. Returns false if we're at the end of the text.