fn from_str()

in tough/src/schema/key.rs [184:219]
36 lines of code
5 McCabe index (conditional complexity)

    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
        if let Ok(public) = serde_plain::from_str::<Decoded<RsaPem>>(s) {
            Ok(Key::Rsa {
                keyval: RsaKey {
                    public,
                    _extra: HashMap::new(),
                },
                scheme: RsaScheme::RsassaPssSha256,
                _extra: HashMap::new(),
            })
        } else if let Ok(public) = serde_plain::from_str::<Decoded<Hex>>(s) {
            if public.len() == ring::signature::ED25519_PUBLIC_KEY_LEN {
                Ok(Key::Ed25519 {
                    keyval: Ed25519Key {
                        public,
                        _extra: HashMap::new(),
                    },
                    scheme: Ed25519Scheme::Ed25519,
                    _extra: HashMap::new(),
                })
            } else {
                Err(KeyParseError(()))
            }
        } else if let Ok(public) = serde_plain::from_str::<Decoded<EcdsaFlex>>(s) {
            Ok(Key::Ecdsa {
                keyval: EcdsaKey {
                    public,
                    _extra: HashMap::new(),
                },
                scheme: EcdsaScheme::EcdsaSha2Nistp256,
                _extra: HashMap::new(),
            })
        } else {
            Err(KeyParseError(()))
        }
    }