Control flow constructions

If

if is an control flow block construction that consumes single boolean type argument and if it is not equals to 0 - jumps into block body, otherwise jumps to own closure end block

0 1 == if 
    // will not happen
end

1 1 == if
    // will fall here
end

While-do

while is an control flow block construction that consumes single boolean type argument and if it is not equals to 0 - jumps into block body, otherwise jumps to own closure end block, but in difference with if, will always jump back to while after reaching own end, so only way to left that loop is out of that condition

var counter int 
counter 0 !<

while counter < 10 do
    // Will print 10 times
    "Hello!" print

    counter copy ?> inc !<
end

In control-flow reference graph: while -> end do -> while end -> while

Additional notes on logic operators

Language supports logical AND (&&) and OR (||), read more at operator / intrinsics page.