Conway's Game of Life: Difference between revisions

This version has been trimmed down from the original REXX program, otherwise the size of the program (with all its options and optional formatting) would

<br>would probably be on the biglarge side for general viewing, &nbsp; and maybe a wee bit complex to demonstrate how to program for this task.

<lang rexx>/*REXX program displays the Conway's game of life, it stops after N repeats. */

signal on halt /*handle a cell growth interruptus. */

rows = p(rows 3) /*the maximum number of cell rows. */

cols = p(cols 3) /* " " " " " colscolumns. */

emp = pickChar(empty 'blank') /*an empty cell character (glyph). */

clearScr = p(clearScreen 0) /* "1" indicates to clear the screen.*/

life! = pickChar(life! '☼') /*the gylph kinda looks like an amebaamoeba. */

reps = p(repeats 2) /*stop pgm if there are 2two repeats.*/

generations = p(generations 100) /*the number of generations allowed. */

usw=max(linesize()-1,cols) /*usable screen width for the display. */

#reps=0; $.=emp /*the universe is new, ··· and barren.*/

gens=abs(generations) /*use this for convenience. /*used for a programming convenience.*/

x=space(peeps); upper x /*elide superfluous spaces; upperuppercase. */

if x=='' then x='"BLINKER'" /*if nonenothing specified, use BLINKER. */

if x=='BLINKER' then x=' "2,1 2,2 2,3'"

if x=='GLIDER' then x=' "48,11 48,12 48,13 49,13 50,12'"

if x=='OCTAGON' then x=' "1,5 1,6 2,4 2,7 3,3 3,8 4,2 4,9 5,2 5,9 6,3 6,8 7,4 7,7 8,5 8,6'"

call assign. /*assign the initial state of all cells.*/

call showCells /*show the initial state of the cells.*/

/* [↓] cell colony grow/live/diegrows, lives, dies.*/

do life=1 for gens; call assign@ /*construct the next generation. of cells.*/

if generations>0 | life==gens then call showCells /*displayshould itcells be displayed? */

fin: exit /*stick a fork in it, we're all done. */

showCells: if clearScr then 'CLS' /* ◄─── change this for your OS. */

call showRows; ?='▒' /*show the rows in the proper order. */

say right(copies('▒'?, usw) life, usw) /*show a fence between the generations.*/

if _=='' then call fin /*if there's no life, then stop the run.*/

if !._ then #reps=#reps+1 /*we detected a repeated cell pattern. */

!._=1 /*existence state &and compare later. */

if reps\==0 & #reps<=reps then return /*so far, so good, regarding repsrepeats.*/

say; say center(' "Life" repeated itself' reps "times, simulation has ended. ", usw,?)

call fin /*stick a fork in it, we're all done. */

$: parse arg _row,_col; return $._row._col==life!

assign$: do r=1 for rows; do c=1 for cols; $.r.c=@.r.c; end; end; return

assign.: do while x\==''; parse var x r '",'" c x; $.r.c=life!; rows=max(rows,r); cols=max(cols,c); end; life=0; !.=0; return

assign@: @.=emp; do r=1 for rows; do c=1 for cols; call assign?; end; end; call assign$; return

halt: say; say 'REXX program halted.'; say; exit 0

neighbors: rm=r-1; rp=r+1; cm=c-1; cp=c+1; return $(rm,cm)+$(rm,c)+$(rm,cp)+$(r,cm)+$(r,cp)+$(rp,cm)+$(rp,c)+$(rp,cp)

p: return word(arg(1), 1)

pickChar: _=p(arg(1)); arg u .; if u=='BLANK' then _='" '"; L=length(_); if L==3 then _=d2c(_); if L==2 then _=x2c(_); return _

This REXX program makes use of &nbsp; '''LINESIZElinesize''' &nbsp; REXX program (or BIF) &nbsp; which is used to determine the screen width (or linesize) of the terminal (console).

▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ "Life" repeated itself 2 times, simulation has ended. ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒