Break and continue
break can be used to prematurely end a while, for, range, rangeRev, or repeat instruction.
    while true {
        sym (x (std.scanI32));
        if (== x 0) {
            break;
        };
        std.println x;
    };
continue can be used to skip over the remaining instructions in the current iteration.
    std.println "Composite numbers:";
    range i 0 100 {
        if (isPrime i) {
            continue;
        };
        std.print '\t' i;
        if (isSquare i) {
            std.print " (square)";
        } (isPerfect i) {
            std.print " (perfect)";
        };
        std.println;
    };
 
    