Test the maximum number of boxes allowed have already been opened. When a new line is printed in the box, d is added to the current indentation. When a new line is printed in the box, d is added to the current indentation. When a new line is printed in the box, d is added to the current indentation. Close the most recently opened tabulation box.
Nothing occurs if insertion point is already on a tabulation mark.
If there is no next tabulation on the line, then a newline is printed and the insertion point moves to the first tabulation of the box. If a new line is printed, offset is added to the current indentation. The out function performs the pretty-printer output. Return the current output functions of the pretty-printer. Abstract data type corresponding to a pretty-printer and all its machinery.