Golang function and function variable semantics - go

Question

Why can't I define a recursive function as a variable? I seem to be able to define arbitrary functions except when they recurse.
This is legal:
func f(i int) int {
if i == 0 {
return 1
}
return i * f(i-1)
}
func main() {
fmt.Println(f(2))
}
This is illegal:
var f func(int) int = func(i int) int {
if i == 0 {
return 1
}
return i * f(i-1)
}
func main() {
fmt.Println(f(2))
}
This is legal and I'm guessing it is just because you can figure out f after initialization:
func main() {
var f *func(int) int;
t := func(i int) int {
if i == 0 {
return 1
}
return i * (*f)(i-1)
}
f = &t
fmt.Println((*f)(2))
}
So it looks like it comes down to function and variable declarations of a function type are treated differently though from the reading the documentation I wouldn't expect that to be the case. Did I miss the part of the documentation detailing this?
I would expect the illegal case to work just because it works in other languages. Like in JavaScript:
(function () {
var f = function (i) {
if (i == 0) {
return 1;
}
return i * f(i - 1);
};
console.log(f(2));
})();

Answer 1

The below code would be the preferred way of doing what you describe. Note that you do not have to create an additional variable, nor do you have a pointer to a function:
package main
import "fmt"
func main() {
var f func(int) int
f = func(i int) int {
if i == 0 {
return 1
}
return i * f(i-1)
}
fmt.Println(f(2))
}