is a setting up a timer. By pressing the button, it sets the value of the variable to the opposite of what is in there at that time and then evaluates the ternary operator. A variable that stores a 0 or 1 is basically AutoHotKey's implementation of a boolean. So at the first key press, you set the value to 1, which resembles true, which then resolves the ternary operator to SetTimer, AutoFire ...
for people who are trying to use and abuse Tinytask; a simple way to record and deploy macros. A place to discuss possible improvements and general experiences.