Problem
1. Supply the following functions; test and exercise the text editor.
(a) next_line
(b) previous_line
(c) goto_line
2. Add a feature to the text editor to put text into two columns, as follows. The user will select a range of line numbers, and the corresponding lines from the buffer will be placed into two queues, the first half of the lines in one, and the second half in the other. The lines will then be removed from the queues, one at a time from each, and combined with a predetermined number of blanks between them to form a line of the final result. (The white space between the columns is called the gutter.)