Function wrap_py_collector_fn

crates/python/src/py_callable.rs:782–795

Wrap a Python callable `(Any) -> None` as a collector for streaming LLM calls. The collector is invoked with each intercepted chunk (after stream response intercepts have been applied). It receives a single JSON-converted Python object argument. If the Python callable raises an exception, it is converted to a `FlowError::Internal` and returned as `Err`, which terminates the stream. If the callabl

(
    py_fn: Py<PyAny>,
)

/// stream. If the callable returns normally (including `None`), the collector
/// returns `Ok(())`.
pub fn wrap_py_collector_fn(
    py_fn: Py<PyAny>,
) -> Box<dyn FnMut(Json) -> std::result::Result<(), FlowError> + Send> {
    Box::new(move |chunk: Json| {
        Python::attach(|py| {
            let py_chunk = json_to_py(py, &chunk)
                .map_err(|e| FlowError::Internal(format!("collector json_to_py failed: {e}")))?;
            py_fn
                .call1(py, (py_chunk,))
                .map_err(|e| FlowError::Internal(format!("Python collector error: {e}")))?;
            Ok(())
        })
    })
}

/// Wrap a Python callable `() -> Any` as a finalizer for streaming LLM calls.
///