invoice: Getter for fallbacks as Address'es

[sgeisler]

The fallback() method returns some custom address payload implementation. A regular fallback_addresses or so that is just a Vec<Address> would be great.

Or an Into<Address> for Fallback.

[futurepaul]

is there any good way right now to convert a Fallback into an Address? just ran into this and not sure the best strat.

[TheBlueMatt]

Sadly only pretty manually, we should fix this!

[futurepaul]

I'll make an Into<Address> based on this logic:

    match fallback {
        Fallback::SegWitProgram { version, program } => {
            let version = WitnessVersion::from_u5(version).unwrap();
            let script = Script::new_witness_program(version, program.as_slice());
            Address::from_script(&script, Network::Bitcoin)
        }
        Fallback::PubKeyHash(pkh) => {
            let pkh = PubkeyHash::from_slice(&pkh).unwrap();
            let script = Script::new_p2pkh(&pkh);
            Address::from_script(&script, Network::Bitcoin)
        }
        Fallback::ScriptHash(sh) => {
            let sh = ScriptHash::from_slice(&sh).unwrap();
            let script = Script::new_p2sh(&sh);
            Address::from_script(&script, Network::Bitcoin)
        }
    }

[jkczyz]

Currently, the builder has a method that takes a Fallback, which are then exposed via an accessor returning Vec<&Fallback>. So an Into<Address> would require a clone since self is taken by value.

We have a few options that I can imagine:

• use the Into approach and live with users needing to clone
• hide Fallback by having separate builder methods for each variant and have the accessor return Vec<Address> like BOLT 12 invoices do
• have an inconsistent interface where the builder remains as it is and the accessor returns Vec<Address>
• add an additional accessor that returns Vec<Address> similar to private_route / route_hints, which would essentially hide the clone from the user

I'm sorta leaning towards the last option to avoid too much change in the interface, but I'm open to other options.

[futurepaul]

sorry I saw this comment after writing this code so thought I'd throw it up here and if it's helpful can iterate, otherwise feel free to close

[jkczyz]

sorry I saw this comment after writing this code so thought I'd throw it up here and if it's helpful can iterate, otherwise feel free to close

Nah, we'll need that or something like that somewhere, regardless. Just need to figure out which interface.