!++
!
! LIFE.EDT -- John Conway's game of LIFE, EDT version....
!
! Uses 21x21 playfield (19x19 calculated points)
! To change playfield size to (say) 40x40, use (from EDT command mode):
!
!       S/19/38/w
!       S/21/40/w
!
! Remember that if the playfield is increased n times, the time taken to
! calculate each pass is multiplied by n squared.
!
! (21x21 is used so that it takes up an entire screenful after a dividing
! line is added.)
!
! The LIFE macro can be run multiple times; the new playfield is copied
! above the old; the old is padded to full size during the calculation.
! The new playfield is in suitable format for re-submission.
!
! Note that the playfield must consist only of spaces or "O"s ("O" 
! representing a live cell).  Don't use tabs.  The playfield needn't be 
! padded out to full size prior to running the macro.
!
! To run this, assuming this file is called LIFE.EDT, enter (at DCL):
!
!       $ EDIT/EDT/COMMAND=LIFE file            (file could be NL:)
!
! Enter your "organism" into the playfield (ie in the middle of the 21x21 
! area), eg:
!
!                       OOO
!                         O
!                        O
!
! Then return to EDT line mode (or use GOLD-7), and type LIFE.
!
!
! Don Stokes (don@gp.co.nz)                             29-Dec-1990
!
!--
!
! Install LIFE....
!
clear life
find buffer life
!
! -----------------------------------------------------------------------------
i;! 
i;! Pad out playfield and move to scratch buffer
i;!
i;c;br ^m 21(-c el 100i ^Z bl +21c del l) br dl ex
i;!
i;! Gather cell groups
i;!
i;clear z
i;c;br 19(19(3(cut+3c paste sel paste appendsr=z -3c+v)-3v +c^M append-c=z)l)ex
i;!
i;! Gather the cells together so we can count them
i;!
i;find buffer z
i;c;br 19(19(+4c d+c bl i:^z undc el 9(i ^Z)bl+c 8(" "d+c bl+c)bl+10c del l))ex
i;!
i;! Calculate cell life
i;!
i;s/: OOO /$O/w/not       ;! Cell surrounded by three live cells is born
i;s/:OOOO /$O/w/not       ;! Live cell surrounded by three others lives
i;s/:OOO /$O/w/not        ;! Live cell surrounded by two others lives
i;s/:O/: /w/not           ;! All others die
i;!
i;! Massage back into playfield
i;!
i;c;br ^m -c 19(32asc 19(d+2c +c d+el) 32asc ^m) ex
i;c;br 21(32asc) ^m +19l 21(32asc) ex
i;!
i;! Copy rebuilt playfield back to where it came from
i;!
i;find last
i;c;br paste=z 21(i-^z) ^m br ex
! -----------------------------------------------------------------------------
!
find last
define macro life
!
! That's all, folks!