I want to make one function support different argument combinations
like that in API:
append
syntax: (append list-1 [list-2 ... ])
syntax: (append array-1 [array-2 ... ])
syntax: (append str-1 [str-2 ... ])
How to write my own function like that. Any document for this?
You define your functions without arguments, like this:
(define (foo) (println $args)) ; -> (lambda () (println $args))
(foo 1 2 3) ; -> (1 2 3)
I put $args, but you can also use functions
You may want to test the arguments' type to decide which signature should you act upon, there is a type function I found on this forum, but I don't recall where or who wrote it, so I'll paste it here:
(define (type x)
(let (types '(
"bool" "bool" "integer" "float" "string" "symbol" "context" "primitive"
"import-simple" "import-libffi" "quote" "list" "lambda" "macro" "array"))
(types (& 0xf ((dump x) 1)))))
Are you referring to arity overloading like we have in clojure.
;trumped-up example
(defn argcount
([] 0)
([x] 1)
([x y] 2)
([x y & more] (+ (argcount x y) (count more))))
-> #'user/argcount
(argcount)
-> 0
(argcount 1)
-> 1
(argcount 1 2)
-> 2
(argcount 1 2 3 4 5)
-> 5