Forum Discussion

Patrick2788's avatar
Patrick2788
Bronze Contributor
Apr 03, 2025

This updated approach for 2025 uses a kernel and MAP to do the heavy lifting.  I tend to err on the side of more parameters and readability.

 

//Kernel coordinates:
x = {-1;-1;-1;0;1;1;1;0};
y = {-1;0;1;1;1;0;-1;-1};


//A simulation of Conway's Game of Life
Conwayλ =

LAMBDA(config,n,
    LET(
    //determine dimensions of the board
        h,ROWS(config),
        w,COLUMNS(config),
    //create matrices of coordinates
        i,SEQUENCE(h)*SEQUENCE(,w,1,0),
        j,TRANSPOSE(i),
    //determine if cell is to be kept or discarded
        generate,MAP(i,j,LAMBDA(i_,j_,
            LET(
                each_cell,INDEX(config,i_,j_),
            //generate coordinates for each cell
            //discard certain coordinates if cell is on perimeter of board
                kernel,(i_+ x>0)*(j_+y>0)*(i_+ x<=h)*(j_+y<=w),
                r,FILTER(i_ + x,kernel),
                c,FILTER(j_+ y, kernel),
            //total the neigbors
                neighbors,SUM(INDEX(config,r,c)),
            //cell is 0 but has exactly 3 neighbors - keep
                revive,(each_cell=0)*(neighbors=3),
            //cell is alive and has 2 or 3 neighbors - keep
                keep,(each_cell=1)*(neighbors=2)+(neighbors=3),
                IF(revive,1,IF(keep,1,0))))),
        IF(n=0,config,Conwayλ(generate,n-1))))

 

Resources