building python interface in lib.rs with functions in other files

[frameadvisors]

What is the proposed way of achieving this?

// add_int.rs
pub fn add(a: i32, b: i32) -> i32 {
    a + b
}

pub fn double(a: i32) -> i32 {
    a * 2
}

// multiply_int.rs
pub fn multiply(a: i32, b: i32) -> i32 {
    a * b
}

// lib.rs
mod add_int;
mod multiply_int;

use add_int::{add, double};
use multiply_int::multiply;

use pyo3::prelude::*;

#[pymodule]
fn pydesign(_py: Python, m: &PyModule) -> PyResult<()> {
    m.add_function(wrap_pyfunction!(add, m)?)?;
    m.add_function(wrap_pyfunction!(double, m)?)?;
    m.add_function(wrap_pyfunction!(multiply, m)?)?;

    Ok(())
}

Here is the error stream:

Compiling pyo3-build-config v0.15.2
Compiling pyo3-macros-backend v0.15.2
Compiling pyo3 v0.15.2
Compiling pyo3-macros v0.15.2
error[E0425]: cannot find value __pyo3_get_function_add in this scope
--> src/lib.rs:12:20
|
12 | m.add_function(wrap_pyfunction!(add, m)?)?;
| ^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope
|
= note: this error originates in the macro proc_macro_call which comes from the expansion of the macro wrap_pyfunction (in Nightly builds, run with -Z macro-backtrace for more info)
error[E0425]: cannot find value __pyo3_get_function_double in this scope
--> src/lib.rs:13:20
|
13 | m.add_function(wrap_pyfunction!(double, m)?)?;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope
|
= note: this error originates in the macro proc_macro_call which comes from the expansion of the macro wrap_pyfunction (in Nightly builds, run with -Z macro-backtrace for more info)
error[E0425]: cannot find value __pyo3_get_function_multiply in this scope
--> src/lib.rs:14:20
|
14 | m.add_function(wrap_pyfunction!(multiply, m)?)?;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope
|
= note: this error originates in the macro proc_macro_call which comes from the expansion of the macro wrap_pyfunction (in Nightly builds, run with -Z macro-backtrace for more info)
warning: unused imports: add, double
--> src/lib.rs:5:15
|
5 | use add_int::{add, double};
| ^^^ ^^^^^^
|
= note: #[warn(unused_imports)] on by default
warning: unused import: multiply_int::multiply
--> src/lib.rs:6:5
|
6 | use multiply_int::multiply;
| ^^^^^^^^^^^^^^^^^^^^^^
libunwind: malformed __unwind_info at 0x181ED0CA8 bad second level page
libunwind: malformed __unwind_info at 0x181ED0CA8 bad second level page

For more information about this error, try rustc --explain E0425.
warning: pydesign (lib) generated 2 warnings
error: could not compile pydesign (lib) due to 3 previous errors; 2 warnings emitted
warning: build failed, waiting for other jobs to finish...

[davidhewitt]

Please update your PyO3 version. 0.15 is very old and probably before support for cross module importing was implemented.