Simplify code generation for ArgInfo (#62)

- Cleanup and simplify `impl ToToken for ArgInfo` which based on
`pyo3/experimental-inspect` feature as before #37
- This can yield breaking changes. Bump up to 0.6.0.

Cargo.toml

@@ -9,7 +9,7 @@ members = [
 resolver = "2"
 
 [workspace.package]
-version = "0.5.4"
+version = "0.6.0"
 edition = "2021"
 
 description = "Stub file (*.pyi) generator for PyO3"

examples/pure/pure.pyi

@@ -12,6 +12,9 @@ class A:
     def show_x(self) -> None:
         ...
 
+    def ref_test(self, x:dict) -> dict:
+        ...
+
 
 class Number(Enum):
     FLOAT = auto()

examples/pure/src/lib.rs

@@ -2,7 +2,7 @@
 mod readme {}
 
 use ahash::RandomState;
-use pyo3::{exceptions::PyRuntimeError, prelude::*};
+use pyo3::{exceptions::PyRuntimeError, prelude::*, types::*};
 use pyo3_stub_gen::{create_exception, define_stub_info_gatherer, derive::*};
 use std::{collections::HashMap, path::PathBuf};
 
@@ -52,6 +52,10 @@ impl A {
     fn show_x(&self) {
         println!("x = {}", self.x);
     }
+
+    fn ref_test<'a>(&self, x: Bound<'a, PyDict>) -> Bound<'a, PyDict> {
+        x
+    }
 }
 
 #[gen_stub_pyfunction]

pyo3-stub-gen-derive/src/gen_stub/arg.rs

@@ -1,8 +1,8 @@
+use super::remove_lifetime;
 use proc_macro2::TokenStream as TokenStream2;
 use quote::{quote, ToTokens, TokenStreamExt};
 use syn::{
     spanned::Spanned, FnArg, GenericArgument, PatType, PathArguments, Result, Type, TypePath,
-    TypeReference,
 };
 
 pub fn parse_args(iter: impl IntoIterator<Item = FnArg>) -> Result<Vec<ArgInfo>> {
@@ -20,8 +20,8 @@ pub fn parse_args(iter: impl IntoIterator<Item = FnArg>) -> Result<Vec<ArgInfo>>
             // Regard the first argument with `PyRef<'_, Self>` and `PyMutRef<'_, Self>` types as a receiver.
             if n == 0 && (last.ident == "PyRef" || last.ident == "PyRefMut") {
                 if let PathArguments::AngleBracketed(inner) = &last.arguments {
-                    assert!(inner.args.len() == 2);
-                    if let GenericArgument::Type(Type::Path(TypePath { path, .. })) = &inner.args[1]
+                    if let GenericArgument::Type(Type::Path(TypePath { path, .. })) =
+                        &inner.args[inner.args.len() - 1]
                     {
                         let last = path.segments.last().unwrap();
                         if last.ident == "Self" {
@@ -57,55 +57,16 @@ impl TryFrom<FnArg> for ArgInfo {
     }
 }
 
-fn type_to_token(ty: &Type) -> TokenStream2 {
-    match ty {
-        Type::Path(TypePath { path, .. }) => {
-            if let Some(last_seg) = path.segments.last() {
-                // `CompareOp` is an enum for `__richcmp__`
-                // PyO3 reference: https://docs.rs/pyo3/latest/pyo3/pyclass/enum.CompareOp.html
-                // PEP: https://peps.python.org/pep-0207/
-                if last_seg.ident == "CompareOp" {
-                    quote! { ::pyo3_stub_gen::type_info::compare_op_type_input }
-                } else {
-                    quote! { <#ty as ::pyo3_stub_gen::PyStubType>::type_input }
-                }
-            } else {
-                unreachable!("Empty path segment: {:?}", path);
-            }
-        }
-        Type::Reference(TypeReference { elem, .. }) => {
-            match elem.as_ref() {
-                Type::Path(TypePath { path, .. }) => {
-                    if let Some(last) = path.segments.last() {
-                        match last.ident.to_string().as_str() {
-                            // Types where `&T: ::pyo3_stub_gen::PyStubType` instead of `T: ::pyo3_stub_gen::PyStubType`
-                            // i.e. `&str` and most of `Py*` types defined in PyO3.
-                            "str" | "PyAny" | "PyString" | "PyDict" => {
-                                return quote! { <#ty as ::pyo3_stub_gen::PyStubType>::type_input };
-                            }
-                            _ => {}
-                        }
-                    }
-                }
-                Type::Slice(_) => {
-                    return quote! { <#ty as ::pyo3_stub_gen::PyStubType>::type_input };
-                }
-                _ => {}
-            }
-            type_to_token(elem)
-        }
-        _ => {
-            quote! { <#ty as ::pyo3_stub_gen::PyStubType>::type_input }
-        }
-    }
-}
-
 impl ToTokens for ArgInfo {
     fn to_tokens(&self, tokens: &mut TokenStream2) {
         let Self { name, r#type: ty } = self;
-        let type_tt = type_to_token(ty);
+        let mut ty = ty.clone();
+        remove_lifetime(&mut ty);
         tokens.append_all(quote! {
-            ::pyo3_stub_gen::type_info::ArgInfo { name: #name, r#type: #type_tt }
+            ::pyo3_stub_gen::type_info::ArgInfo {
+                name: #name,
+                r#type: <#ty as ::pyo3_stub_gen::PyStubType>::type_input
+            }
         });
     }
 }

pyo3-stub-gen-derive/src/gen_stub/util.rs

@@ -36,6 +36,14 @@ pub fn remove_lifetime(ty: &mut Type) {
             rty.lifetime = None;
             remove_lifetime(rty.elem.as_mut());
         }
+        Type::Tuple(ty) => {
+            for elem in &mut ty.elems {
+                remove_lifetime(elem);
+            }
+        }
+        Type::Array(ary) => {
+            remove_lifetime(ary.elem.as_mut());
+        }
         _ => {}
     }
 }

pyo3-stub-gen/Cargo.toml

@@ -21,7 +21,7 @@ serde.workspace = true
 toml.workspace = true
 
 [dependencies.pyo3-stub-gen-derive]
-version = "0.5.4"
+version = "0.6.0"
 path = "../pyo3-stub-gen-derive"
 
 [features]

pyo3-stub-gen/src/stub_type/collections.rs

@@ -1,6 +1,15 @@
 use crate::stub_type::*;
 use std::collections::{BTreeMap, BTreeSet, HashMap};
 
+impl<T: PyStubType> PyStubType for &T {
+    fn type_input() -> TypeInfo {
+        T::type_input()
+    }
+    fn type_output() -> TypeInfo {
+        T::type_output()
+    }
+}
+
 impl<T: PyStubType> PyStubType for Option<T> {
     fn type_input() -> TypeInfo {
         let TypeInfo { name, mut import } = T::type_input();

pyo3-stub-gen/src/stub_type/pyo3.rs

@@ -1,5 +1,6 @@
 use crate::stub_type::*;
 use ::pyo3::{
+    basic::CompareOp,
     pybacked::{PyBackedBytes, PyBackedStr},
     pyclass::boolean_struct::False,
     types::*,
@@ -78,3 +79,4 @@ impl_builtin!(PyByteArray, "bytearray");
 impl_builtin!(PyBytes, "bytes");
 impl_builtin!(PyBackedBytes, "bytes");
 impl_builtin!(PyType, "type");
+impl_builtin!(CompareOp, "int");