Pass a function as a parameter in Netlogo

问题

In many other programming languages, you can pass a function as an argument to another function and call it from within the function.

Is there anyway to do this in Netlogo?

Such as the following:

;; x,y,z are all ints
to-report f [x y z]
  report x + y + z
end

;; some-function is a function
;; x y and z are ints
to-report g [some-function x y z]
  report (some-function x y z) + 2
end

to go
  show g f 1 2 3
end

This would be a nice feature. I'm trying to implement an abstract local search algorithm which this would be nice for passing in objective functions and such.

回答1:

You can pass functions as parameters by creating a task and using the runresult to execute the task.

;; x,y,z are all ints
to-report f [x y z]
  report x + y + z
end

;; some-function is a function
;; x y and z are ints
to-report g [some-function x y z]
  report (runresult some-function x y (z + 2))
end

to go
  show g (task f) 1 2 3
end

回答2:

As of Netlogo 6.0.1, the arrow syntax replaced tasks. The below does the same thing as the accepted answer but with the updated syntax.

to-report f [x y z]
  report x + y + z
end

;; some-function is a function
;; x y and z are ints
to-report g [some-function x y z]
  report (runresult some-function x y (z + 2))
end


to go
  show g [[x y z] -> (f x y z)] 1 2 3
end

回答3:

you can't pass the function as a function (I believe), but you can certainly pass the function name as text and then use the runresult primitive to run the function. Messy but doable.

来源：https://stackoverflow.com/questions/36539334/pass-a-function-as-a-parameter-in-netlogo

标签

function

netlogo