Updated is_mine documentation

[matthiasdebernardini]

Description

To clarify the purpose of a method and to indicate how to get more information from the wallet

Notes to the reviewers

We can also change the how is_mine works by calling derivation_of_spk directly, so its more clear how the internals work. This way rather than having the docs explicitly call out the method, they can jump to source.

Checklists

All Submissions:

• [ x] I've signed all my commits
• [ x] I followed the contribution guidelines
• [ x] I ran cargo fmt and cargo clippy before committing

[LLFourn]

Sure I support reimplementing in terms of derivation_of_spk. Also there might be a better name for it.

[matthiasdebernardini]

    /// Finds how the wallet derived the script pubkey `spk`.
    ///
    /// Will only return `Some(_)` if the wallet has given out the spk.
    pub fn derivation_of_spk(&self, spk: &Script) -> Option<(KeychainKind, u32)> {
        self.indexed_graph.index.index_of_spk(spk)
    }

Also there might be a better name for it

@LLFourn rename this? Could be find_spk_derivation or find_spk?

Also with regards to;

Will only return Some(_) if the wallet has given out the spk

I think this means to say that it will return Some(_) if the spk is findable/derivable, to me, "has given out" means its tracking which spks its been giving out which sounds inaccurate.

[LLFourn]

    /// Finds how the wallet derived the script pubkey `spk`.
    ///
    /// Will only return `Some(_)` if the wallet has given out the spk.
    pub fn derivation_of_spk(&self, spk: &Script) -> Option<(KeychainKind, u32)> {
        self.indexed_graph.index.index_of_spk(spk)
    }

Also there might be a better name for it

@LLFourn rename this? Could be find_spk_derivation or find_spk?

I don't like find because it implies it's not just doing a lookup. find in rust is used in iterators to go through each element and return the first match.

Also with regards to;

Will only return Some(_) if the wallet has given out the spk

I think this means to say that it will return Some(_) if the spk is findable/derivable, to me, "has given out" means its tracking which spks its been giving out which sounds inaccurate.

I think it was accurate. That's one of the main functions of the KeychainTxOutIndex is to track which has given out. However I think this will now return results for things that have not yet been given out because of the "lookahead" feature so I do think the docs needs to be updated to say that if it matches a script pubkey that is has derived internally.

[notmandatory]

Since this is just a docs and internal implementation change that doesn't change the API I'd like to move it to a post 1.0 milestone.

[matthiasdebernardini]

I closed this but would like to revisit this post 1.0 release.