Artifact 128157171bc43bb34c917b92a1ea4e5039cad9c88b2af180c01aba24261638ff:

• File psl-1983/emode/buffer-position.sl — part of check-in [eb17ceb7f6] at 2020-04-21 19:40:01 on branch master — Add Reduce 3.0 to the historical section of the archive, and some more
  files relating to version sof PSL from the early 1980s. Thanks are due to
  Paul McJones and Nelson Beebe for these, as well as to all the original
  authors.

  git-svn-id: https://svn.code.sf.net/p/reduce-algebra/code/historical@5328 2bfe0521-f11c-4a00-b80e-6202646ff360 (user: arthurcnorman@users.sourceforge.net, size: 1219) [annotate] [blame] [check-ins using] [more...]

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% BUFFER-POSITION.SL - EMODE Buffer Position Objects
% 
% Author:      Alan Snyder
%              Hewlett-Packard/CRC
% Date:        6 July 1982
%
% This file implements objects that store buffer positions.
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

(CompileTime (load common))

(fluid '(CurrentLineIndex point))

(de buffer-position-create (line-number column-number)
  (cons line-number column-number))

(de buffer-position-line (bp)
  (car bp))

(de buffer-position-column (bp)
  (cdr bp))

(de buffer-position-compare (bp1 bp2)
  (cond ((< (buffer-position-line bp1)   (buffer-position-line bp2))   -1)
	((> (buffer-position-line bp1)   (buffer-position-line bp2))    1)
	((< (buffer-position-column bp1) (buffer-position-column bp2)) -1)
	((> (buffer-position-column bp1) (buffer-position-column bp2))  1)
	(t 0)))

(de buffer-get-position ()
  (buffer-position-create CurrentLineIndex point))

(de buffer-set-position (bp)
  (if bp (progn
    (PutLine)
    (setf CurrentLineIndex (buffer-position-line bp))
    (setf point (buffer-position-column bp))
    (GetLine CurrentLineIndex)
    )))