Clojure功能检查

Question

When i have 3 functions in a program, how do i check a specific function name ? I want to know the name of those function for the sake of function selection.

Let say linear-kernel function, logistic-kernel function, and non-negative function, when i call the program, one of those function is called and i should to check whether it was linear, logistic or non-negative function, so i can execute another function related with the selected function.

I think doing function selection will save my time from repeating the base code. But doing function selection maybe is not the best design that i could use in Clojure.

FYI, at this level, i already use the "meta" keyword to access the function name, but when i create

(defn isKernel [krn]
  (if (= (str (:name (meta #'krn))) "logistic-kernel") 1 0))

The compiler cannot resolve the 'krn' var

Answer 1

In Clojure functions are values, just like the number 4. This is a big part of the underpinnings of much of the language (and functional programming in general). Most of the time we store functions in vars though this is not required. * So rather than checking to see if the name of a passed function matches a known name, it makes more sense to ask " " as @cgrand points out this can be accomplished simply by calling = .

If you are doing this kind of dispatch there is a good change that protocols are a better tool than rolling your own

*they do have names for the purpose of creating recursive function literals though thats not what I'm getting at here.