purpose of defn in Clojure -


i'm little puzzled role of defn. if fn produced anonymous functions, understand need construct combines functionality of def , fn, fn can create named functions. @ least in repl, don't see how usage differs defn.

when provide name symbol fn, it's only bound within function definition function object itself. allow anonymous functions call (clojure - special forms).

so create function fn bound global accessible name, have use

(def somename      (fn ...body...

and defn shortcut this.

(defn somename      ...body...

in response comment, fresh repl:

give me clojure: > (fn foo [] (+ 1 3)) #<sandbox31764$eval31779$foo__31780 sandbox31764$eval31779$foo__31780@12eae8eb> > (foo) java.lang.runtimeexception: unable resolve symbol: foo in context > (defn foo [] (+ 1 3)) #'sandbox31764/foo > (foo) 4 >

as can see, can't call foo function created fn, because it's not bound var.


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