What I am doing

 func foo(a string) {}

 func bar(b, c string)

 type fn func(string)

 m: = map[string] fn {
     "a": "foo",
     "b": "bar"
 }

What is output

when I call function like this

  m["a"]("Hello")
  m["b"]("Hello", "World")

I got an error because type fn func(string) here fn have single parameter but I pass double parameter in m["b"]("Hello", "World")

Error : [ cannot use (type func(string, string)) as type fn in map value ]

What I am looking for

I want to make dynamic type fn func(string) so that I can pass number of parameter so that I can call like this

  m["a"]("Hello")
  m["b"]("Hello", "World")

Solve using interface

m: = map[string]interface{} {
     "a": "foo",
     "b": "bar"
 }

Create a variadic function which will take any number of arguments as parameters on passing it to function.

 func foo(nums ...string) {}

 m:= map[string]fn{
     "a": "foo",
     "b": "bar"
 }

For more on variadic functions check this Answer