[derive-backend] Add utils::if_type_is_python

pyo3-derive-backend/src/method.rs

@@ -85,16 +85,7 @@ impl<'a> FnSpec<'a> {
                         }
                     };
 
-                    let py = match ty {
+                    let py = crate::utils::if_type_is_python(ty);
-                        syn::Type::Path(syn::TypePath { ref path, .. }) => {
-                            if let Some(segment) = path.segments.last() {
-                                segment.value().ident == "Python"
-                            } else {
-                                false
-                            }
-                        }
-                        _ => false,
-                    };
 
                     let opt = check_arg_ty_and_optional(name, ty);
                     arguments.push(FnArg {
@@ -209,6 +200,11 @@ impl<'a> FnSpec<'a> {
         }
         false
     }
+
+    /// A FnSpec is valid as getter if it has no argument or has one argument of type `Python`
+    pub fn valid_as_getter(&self) -> bool {
+        false
+    }
 }
 
 pub fn is_ref(name: &syn::Ident, ty: &syn::Type) -> bool {

pyo3-derive-backend/src/module.rs

@@ -64,16 +64,7 @@ fn wrap_fn_argument<'a>(input: &'a syn::FnArg, name: &'a Ident) -> Option<method
                 _ => panic!("unsupported argument: {:?}", cap.pat),
             };
 
-            let py = match cap.ty {
+            let py = crate::utils::if_type_is_python(&cap.ty);
-                syn::Type::Path(ref typath) => typath
-                    .path
-                    .segments
-                    .last()
-                    .map(|seg| seg.value().ident == "Python")
-                    .unwrap_or(false),
-                _ => false,
-            };
-
             let opt = method::check_arg_ty_and_optional(&name, &cap.ty);
             Some(method::FnArg {
                 name: ident,
@@ -111,7 +102,7 @@ fn extract_pyfn_attrs(
                         }
                         _ => panic!("The first parameter of pyfn must be a MetaItem"),
                     }
-                    // read Python fonction name
+                    // read Python function name
                     match meta[1] {
                         syn::NestedMeta::Literal(syn::Lit::Str(ref lits)) => {
                             fnname = Some(syn::Ident::new(&lits.value(), lits.span()));

pyo3-derive-backend/src/utils.rs

@@ -2,12 +2,24 @@
 
 use proc_macro2::Span;
 use proc_macro2::TokenStream;
-use syn;
 
 pub fn print_err(msg: String, t: TokenStream) {
     println!("Error: {} in '{}'", msg, t.to_string());
 }
 
+/// Check if the given type `ty` is `pyo3::Python`.
+pub fn if_type_is_python(ty: &syn::Type) -> bool {
+    match ty {
+        syn::Type::Path(ref typath) => typath
+            .path
+            .segments
+            .last()
+            .map(|seg| seg.value().ident == "Python")
+            .unwrap_or(false),
+        _ => false,
+    }
+}
+
 // FIXME(althonos): not sure the docstring formatting is on par here.
 pub fn get_doc(attrs: &[syn::Attribute], null_terminated: bool) -> syn::Lit {
     let mut doc = Vec::new();