Add doc for #[pyclass_repr] (#8110)

lib/edge/python/codegen/src/lib.rs

@@ -1,5 +1,45 @@
 mod pyclass_repr;
 
+/// `#[pyclass_repr]` - implements `trait Repr`.
+///
+/// Only methods with `#[getter]` are included into the output.
+///
+/// # Usage example
+///
+/// Input:
+/// ```ignore
+/// #[pyclass_repr]
+/// #[pymethods]
+/// impl PyMyStruct {
+///     #[getter]
+///     pub fn foo(&self) -> &str {
+///         &self.0.foo
+///     }
+///
+///     #[getter]
+///     pub fn bar(&self) -> f32  {
+///         self.0.bar
+///     }
+///
+///     pub fn __repr__(&self) -> String {
+///         self.repr()
+///     }
+/// }
+/// ```
+///
+/// Generated output is roughly equivalent to:
+/// ```ignore
+/// impl crate::repr::Repr for PyMyStruct {
+///     fn fmt(&self, f: &mut crate::repr::Formatter<'_>) -> std::fmt::Result {
+///         use crate::repr::WriteExt as _;
+///
+///         f.class::<Self>(&[
+///             ("foo", &self.foo()),
+///             ("bar", &self.bar()),
+///         ])
+///     }
+/// }
+/// ```
 #[proc_macro_attribute]
 pub fn pyclass_repr(
     _attributes: proc_macro::TokenStream,

lib/edge/python/src/repr.rs

@@ -4,6 +4,7 @@ use std::fmt;
 pub use edge_py_codegen::pyclass_repr;
 use pyo3::PyTypeInfo;
 
+/// Can be implemented using [macro pyclass_repr].
 pub trait Repr {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result;
 

lib/macros/src/lib.rs

@@ -2,6 +2,7 @@ use proc_macro::TokenStream;
 
 mod anonymize;
 
+/// Grep for `trait Anonymize` for doc.
 #[proc_macro_derive(Anonymize, attributes(anonymize))]
 pub fn derive_anonymize(input: TokenStream) -> TokenStream {
     match anonymize::derive_anonymize(input.into()) {