How to write immutable code in Go
When we talk about immutability in Go, we are specifically focusing on how to have immutable structs in our code. At the core of this, we have to take a look at how Go uses pointers and the difference between pass-by-value and pass-by-reference. This is something that trips up new Go programmers, and there is a sufficient amount of edge cases where even more seasoned Go programmers will occasionally shoot themselves in the foot.
In essence, it comes down to whether or not we are using pointers in our code when passing around structs to functions. If our code is entirely free of pointers, then we would also be writing immutable code.
To demonstrate this, take a look at the following piece of code. We have a struct to define a person, and a function to change the name of this person:
type Person struct {
name string
age int
}
func main() {
p := Person{
...