is TRUE, removes the the second item on the EXEC stack, leaving the first item to be executed. Otherwise, removes the first item, leaving the second to be executed. Acts as a NOOP unless there are at least two items on the EXEC stack and one item on the BOOLEAN stack</p>
<h2><a href="#exec-when" id="exec-when"></a>:exec_when</h2>
<p>If the top BOOLEAN is TRUE, leaves the first item on the EXEC stack to be executed. Otherwise, it removes it. Acts as a NOOP unless there is at least one item on the EXEC stack 