reflection - How do I get the values of arguments passed inside a func() argument in GO? -

i trying create middleware inside routes , wondering how 1 can values of arguments passed inside func() argument.

for example:

func (c appcontainer) get(path string, fn func(rw http.responsewriter, req *http.request)) {      // how values of rw , req passed in fn func()?      c.providers[router].(routable).get(path, fn) } 

i looked through reflection docs it's not clear me or perhaps there simpler way?

edited (solution)

it turns out reflection not needed, suggested adam in response post, jason on his golang-nuts reply question.

the idea create new anonymous function intercepts parameters passed modification/enhancement before calling original function.

this ended doing , worked charm, posting in case helps else:

type handlerfn func(rw http.responsewriter, req *http.request)  func (c appcontainer) get(path string, fn handlerfn) {     nfn := func(rw http.responsewriter, req *http.request) {         c.providers[logger].(loggable).info("[%s] %s", req.method, req.url.path)         fn(rw, req)     }     c.providers[router].(routable).get(path, nfn) } 

simple answer: don't. not @ place @ least

the variables rw , req make first sense if function fn called. (or function calls fn, have rw , req variables)

in case appcontainer uses routes configured

to better understand how middleware concept works simple example can found here: https://golang.org/doc/articles/wiki/

you might want scroll down "introducing function literals , closures"