Need to return only if matches

help
1

need to return token only if path starts else do nothing

pub fn build(self, stream: &TcpStream) {
        let client_id = self.client_id;
        let scope = &self.scope;
        let state = self.state;
        let login = self.login;
        let redirect = self.redirect;

        let path = buffer_to_path(self.buffer);

        if path.starts_with("/login") {
            Self::oauth_screen(stream, client_id, scope, &state);
        }
        if path.starts_with("/callback?code=") {
            let code = github_authorization_code(&path);

            let authorization = github_access_token(
                code.to_string(),
                client_id,
                self.client_secret,
                redirect,
                stream,
            )
            .unwrap();

            let token = github_decode(&authorization);
            println!("{:?}", token);
        }
        // println!("{}", "ertyuiop");
    }```
2

Returning some type conditionally is usually done by wrapping it in an Option.

3

but need only value no none ?

4

Well, what do you want to return when your path doesn't start with your designated prefix?

5

return nothing if dont match
but return token only if matches path

6

Right. You can't exactly return nothing from a function that returns, say, a String. That would violate the function's signature. Even in OOP languages without null-safety an implicit null-pointer would be returned in cases where you return "nothing". Rust makes control flow more explicit, encoding the fact that a function might return "nothing" in its return type by returning Option<String> instead of String, for example, where Option::None indicates to the caller that "nothing" was returned.

1 Like
7

if there any other way to return value only if path matches else nothing

8

You can loop forever, or panic, or otherwise terminate the program.

9

but panic and terminating cause shutdown the server ?
is there any other way to handle to shift the token to another variable then use in main ?

10

Pass the variable you want to store the token in as mutable reference to the function and assign the token to it.

11

okie