I'm wondering if there's a way through fmt
to specify the way a string would get outputted for specific types. For example, I have a token
struct that contains a bunch of information on the token, like token type (which is an int, but for clarity reasons, it would make more sense if I could output the name of the token type as a string).
So when I print a specific type of variable, is there a straightforward way to specify/implement the string output of such a type?
If that doesn't really make sense, Rust has an excellent form of doing so (from their doc)
use std::fmt;
struct Point {
x: i32,
y: i32,
}
impl fmt::Display for Point {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "({}, {})", self.x, self.y)
}
}
let origin = Point { x: 0, y: 0 };
println!("The origin is: {}", origin); // prints "The origin is: (0, 0)"
You need to implement the interface Stringer
, like this:
import "fmt"
type Point struct {
x int
y int
}
func (p Point) String() string {
return fmt.Sprintf("(%d, %d)", p.x, p.y)
}
func main() {
fmt.Println(Point{1, 2})
}
In Go you don't specify which interfaces a type implements, you just implements the required methods.