You can create an alias function that you may use as a condition. Your function returns either 0 or 1, so you could setup the alias like this:
+On function "I'mReturningOne"
->Function: Set return value to 1
+On Alias "BeTrueIfOne"
++Function.I'mReturningOne equal to 1
->Function: (Alias) Return true
Then you can call the alias as a condition:
+"BeTrueIfOne" (isolated)
->Do amazing things if return value is one (= alias returns true)
+Else
->Do even more fun stuff if return value is zero (= alias returns false)