🚀 go-pugleaf

From article <1991Jul19.050030.27755@ux1.cso.uiuc.edu>,
by peltz@cerl.uiuc.edu (Steve Peltz):
> 
> The Tutor language used on PLATO systems has a "use" command which
> specifies a file name and a block name.
> 
Thanks for jogging my memory!  Here's the relevant quote:

   From "PLATO User's Memo:  Summary of TUTOR Commands and System Variables"
   compiled by Elane Avner, May 20, 1974
   published by the PLATO Services Organization of the
   Computer-Based Education Research Laboratory,
   University of Illinois at Urbana.

   Quoted from page S10:

   use    inserts specified block from specified lesson into lesson being
          condensed

          use      lesson name, block name
          use      block name    (lesson has been specified by previous
                                  -use-)

          (Only one lesson may be referenced by -use-.  Use codes on
          lessons must match.)

   End quote.

   Background:  The term "lesson" is the PLATO technical jargon for a
   source file.  Lessons were divided into named blocks as part of the
   file system organization.  It was common for individual blocks to
   contain groups of related subroutines (called "units" in the TUTOR
   language of the PLATO system).

Thus, we have old prior art for an include mechanism that takes a named
subsection of a document, and as I previously stated, we also have prior
art for an include mechanism that uses conditional directives within the
included document to determine what subsection is included.

					Doug Jones
					jones@cs.uiowa.edu