list structure insertion macro

     on file /lib/lisp/mi.tec is a teco macro which automatically
formats  list  structure  as  you  type it.  get the macro into a
q-register and execute it when the buffer pointer is at  the  be-
ginning  of  a  line.  any characters typed will be inserted into
the buffer.  when a line  feed  is  typed,  sufficient  tabs  and
blanks  are inserted to indent the new line just the way the lisp
pretty-printer would indent it.  the tabs and blanks  are  echoed
so  that what appears on the screen corresponds to what is in the
file. super-brackets are handled appropriately. if too many right
parentheses  are  typed, a warning message is printed and the ex-
tras are ignored for formatting purposes. if you  make  a  typing
error, a control q will delete the current line. the deleted text
will disappear from the screen and the  cursor  will  be  reposi-
tioned.  successive control-q's continue to delete lines and move
the cursor up the screen. exit the macro with control-c.

     the macro uses q-registers 1, 2, 3, a, c, and s.

     One can bring the macro into teco by the teco command:
*em/lib/lisp/mi.tec$i$$
which will bring it into q-register i,  where it can be  executed
with *mi$$. (the * is teco's prompt and the dollar signs are alt-
modes).

glytchs:

     the ↑u feature only works on terminals for which  154  octal
     moves  the  cursor  up  (most of the data-points are ok). on
     other terminals you can still delete lines with ↑u  but  the
     deleted text will remain on the screen.

     when  the  message  "too many right parentheses" appears, it
     will take two control u's to get rid of the offending line.

     if more than one control-u is  used,  they  don't  disappear
     from the screen.

     you  can  control-u right to the beginning of the text which
     you have inserted. if you hit ↑u again, and there was  stuff
     above  what  you  had inserted, there are no gaurantees that
     you will come out alive.

  bug:

     if a left superbracket governs  the  line  above  a  deleted
     line,  the  cursor  isn't repositioned properly. this can be
     remedied by another ↑u.


     This macro was written by greg nelson  for  use  in  applied
     math 110 and other courses using lisp.