Keep rust code unchanged

[SimonG85]

I have a question.

I'm writing an algorithm that I want to use only in rust but this algo needs some parameters as result of an optimisation.

Since there is a lack of optimisation library in rust (with respect to python) I need to expose some struct in python and some methods with the objective function.

My rust struct
struct Foo <I, S>{
only members that implement IntoPy trait
}

impl Foo {
methods, for example my function to optimise
}

In the python object I need only a concrete implementation of I and S, say i64 and String.

How can I define a struct to wraps Foo into a Python object without changing the rust code (that I need to use after the optimisation)? And I need to export the optimisation function too.

I made a copy of the rust Foo with pyclass and it works but it's a code duplication and I want to avoid if possible.

Thanks.

[messense]

Is this what you want?

use pyo3::prelude::*;

pub struct Foo<I, S> {
    a: I,
    b: S,
}

#[pyclass]
pub struct PyFoo {
    inner: Foo<i64, String>,
}

https://www.rustexplorer.com/b/z4p7n1

[SimonG85]

OMG, it was easier than expected!
Yes, thanks to your advice I'm able to export python object by using rust struct and function.
In particular I defined the new fuction as follows:

Self {
inner: Foo::new(...)
}
where new is a rust function of rust Foo.
Many thanks!

[SimonG85]

Another question. In this case I cannot annotate with get and set of pyo3. In this case, do I have to implement getters and setters in rust and expose in python, right?

[davidhewitt]

Yes, though I wonder if one day we could have something like

#[pyclass(getters = (bar = self.inner.bar))]
struct PyFoo {
    inner: Foo
}

Might be too powerful 😂

[SimonG85]

Yes, indeed. Thanks!