Functions

• A function is a body of code that gets parameters.
• Depending on the parameters the function may calculate a return value and may have side effects
• A simple version of this can be done by making rules that only run when a particular fact is set.
• When the function is finished, that fact is changed.
• To call the function, you need to set up the parameters and then set the fact.
• This is only a simple version of function calls, because it does not allow recursive functions.
• For example: (defrule start-loopfunc (start myfunc) => (assert (value 1)) (assert (in myfunc)))
• (defrule loopfunc (in myfunc) (value ?a) (test (< ?a 5)) => (assert (value (+ ?a 1))))
• (defrule endfunc ?f1 <- (in myfunc) (value ?a) (test (= ?a 5)) => (retract ?f1))