Question: What is the recommended approach of passing a data type with private field/type?

[momotaro1105]

Have been working on the 'curve25519-dalek' crate in Rust to generate a private and public keypair in flutter. However, the 'PublicKey' struct, defined externally within the aforementioned crate contains nested fields that are defined in private/internal modules, and hence cannot be re-exported to 'api.rs'.

What would be the best practice to handle this? Here is an example;

pub use curve25519_dalek::{
    edwards::{EdwardsPoint},
    ristretto::{CompressedRistretto, RistrettoPoint},
    scalar::{Scalar},
    field::{FieldElement, FieldElement51},          // module 'field' is private and throws an error on compile
};
pub use schnorrkel::{
    keys::{
        Keypair, 
        SecretKey, 
        PublicKey
    },
    points::{RistrettoBoth},
    sign::{Signature},
};

// keypair
#[frb(mirror(Keypair))]
pub struct _Keypair {
    pub secret: SecretKey,
    pub public: PublicKey,
}

// public key
#[frb(mirror(PublicKey))]
pub struct _PublicKey(pub (crate) RistrettoBoth);

...........

#[frb(mirror(EdwardsPoint))]
pub struct _EdwardsPoint {
    pub(crate) X: FieldElement,
    pub(crate) Y: FieldElement,
    pub(crate) Z: FieldElement,
    pub(crate) T: FieldElement,
}

#[frb(mirror(FieldElement))] 
pub type _FieldElement = backend::serial::u64::field::FieldElement51;

#[frb(mirror(FieldElement51))] 
pub struct _FieldElement51(pub (crate) [u64; 5]);

[welcome[bot]]

Hi! Thanks for opening your first issue here! :smile:

[fzyzcjy]

does this help? -> https://github.com/fzyzcjy/flutter_rust_bridge/pull/795

[momotaro1105]

does this help? -> #795

Thank you. Having a look, might take some time for me to get a good understanding.

[momotaro1105]

Sorry for late, I do think the implementation of opaque types is what I am looking for, but not confident enough to say for sure until I actually use - it given my lack of programming experience.

In the meantime, I decided to power through it. While I know it is NOT best practice, I made changes to the external dependencies to turn some private data types/modules to public and then re-exporting the same to api.rs. In doing so, I noticed that cargo update or ctrl + s doesn't properly reflect the changes to the larger flutter project. Is there an alternative command that I can run? I'm sorry if I missed it in the official docs.

[fzyzcjy]

that sounds like a hack. a way is to create your own fork of source code and modify it.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[github-actions[bot]]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new issue.