better ergonomics: hide generics in packages

Signed-off-by: Luca Fulchir <luca.fulchir@runesauth.com>

bok-macro/src/lib.rs

@@ -150,10 +150,26 @@ pub fn pkg_fn_to_code(attrs: TokenStream, input: TokenStream) -> TokenStream {
 /// #[::bok::package(::bok::PkgEmpty)]
 /// pub struct MyPkg {}
 /// ```
-#[::macro_magic::import_tokens_attr]
 #[proc_macro_attribute]
 pub fn package(attrs: TokenStream, input: TokenStream) -> TokenStream {
-    crate::pkgs::package(attrs, input, __source_path)
+    crate::pkgs::package(attrs, input)
+}
+
+/// **Internal**. try not to use
+/// Use as #[::bok::package(MyBasePackage<R>)]
+/// Will setup a `base` field that is the given base package
+/// and add `#[derive(::bok::Package)]`
+/// needs generics
+///
+/// e.g.:
+/// ```
+/// #[::bok::package_path(::base::pkg<R>)]
+/// pub struct MyPkg {}
+/// ```
+#[::macro_magic::import_tokens_attr]
+#[proc_macro_attribute]
+pub fn package_path(attrs: TokenStream, input: TokenStream) -> TokenStream {
+    crate::pkgs::package_path(attrs, input, __source_path)
 }
 
 /// Specify one or more build-time dependencies
@@ -170,12 +186,17 @@ pub fn deps_build(attrs: TokenStream, input: TokenStream) -> TokenStream {
 }
 
 /// Use as #[::bok::package_impl]
-/// will add `#[::bok::package_impl_base(..)]` with proper arguments
-/// and export the resulting symbols
+/// adds the right generics to the package.
+///
+/// extra calls and changes are added to `::bok::Pkg` and ::std::Default traits
 ///
 /// e.g.:
 /// ```
 /// #[::bok::package_impl]
+/// impl Default for Mypackage {
+///   fn default() -> Self { ... }
+/// }
+/// #[::bok::package_impl]
 /// impl ::bok::Pkg for MyPackage {
 ///   fn build(&self) -> Result<(),()> {
 ///       ...

bok-macro/src/pkgs.rs

@@ -43,7 +43,37 @@ pub(crate) fn pkg_fn_to_code(
     asdf.into()
 }
 
-pub(crate) fn package(
+pub(crate) fn package(attrs: TokenStream, input: TokenStream) -> TokenStream {
+    let local = parse_macro_input!(input as ::syn::ItemStruct);
+    let mut path = parse_macro_input!(attrs as ::syn::Path);
+
+    let last = path.segments.last().unwrap();
+    if last.arguments.is_empty() {
+        // make sure all the packages have generics, and if not add the
+        // repo as generic aka: rewrite
+        //   "#[package(my::pkg)]" -->> "#[package(my::pkg<R>)])"
+        //   unless it's '::bok::PkgEmpty'
+        if path.segments.len() != 2
+            || path.segments[0].ident.to_string() != "bok"
+            || path.segments[1].ident.to_string() != "PkgEmpty"
+        {
+            let repo_argument = {
+                let generic_id: ::syn::Path = ::syn::parse_quote!(id<R>);
+                generic_id.segments.last().unwrap().arguments.clone()
+            };
+            path.segments.last_mut().unwrap().arguments = repo_argument;
+        }
+    }
+
+    return quote! {
+        use ::bok_macro::package_path;
+        #[::bok_macro::package_path(#path)]
+        #local
+    }
+    .into();
+}
+
+pub(crate) fn package_path(
     attrs: TokenStream,
     input: TokenStream,
     __source_path: TokenStream,
@@ -183,9 +213,34 @@ pub(crate) fn deps_build(
     attrs: TokenStream,
     input: TokenStream,
 ) -> TokenStream {
-    let packages = parse_macro_input!(attrs as crate::PathList);
-
+    let mut packages = parse_macro_input!(attrs as crate::PathList);
     let local = parse_macro_input!(input as ::syn::ItemStruct);
+
+    // make sure all the packages have generics, and if not add the repo as
+    // generic aka: rewrite
+    //   "#[deps_build(my::pkg)]" -->> "#[deps_build(my::pkg<R>)])"
+    let mut rewrite = false;
+    let repo_argument = {
+        let generic_id: ::syn::Path = ::syn::parse_quote!(id<R>);
+        generic_id.segments.last().unwrap().arguments.clone()
+    };
+    for p in packages.0.iter_mut() {
+        let last = p.segments.last_mut().unwrap();
+        if last.arguments.is_empty() {
+            rewrite = true;
+            last.arguments = repo_argument.clone();
+        }
+    }
+    if rewrite {
+        let p_list = packages.0.into_iter();
+        return quote! {
+            #[::bok::deps_build(#(#p_list,)*)]
+            #local
+        }
+        .into();
+    }
+    let packages = packages; // remove mut;
+
     let ::syn::Fields::Named(local_fields) = local.fields else {
         use ::syn::spanned::Spanned;
         return ::syn::Error::new(
@@ -240,7 +295,32 @@ pub(crate) fn package_impl(
     _attrs: TokenStream,
     input: TokenStream,
 ) -> TokenStream {
-    let ast = parse_macro_input!(input as ::syn::ItemImpl);
+    let mut ast = parse_macro_input!(input as ::syn::ItemImpl);
+
+    if let Some((_, trait_name, _)) = &ast.trait_ {
+        let s = &trait_name.segments;
+        if s.len() != 2
+            || s[0].ident.to_string() != "bok"
+            || s[1].ident.to_string() != "Pkg"
+        {
+            //
+            // only add the generic parameter and nothing else
+            //
+            let t_id = &ast.self_ty;
+            let g: ::syn::ItemImpl = ::syn::parse_quote! {
+                impl<R> trait_name for #t_id<R> where R: ::bok::Repository {}
+            };
+            ast.generics = g.generics;
+            ast.self_ty = g.self_ty;
+            // TODO: if the trait is `::std::default::Default`
+            //   then add the `_bok_base` and `_bok_repo` defaults automatically
+            return quote! {
+                #ast
+            }
+            .into();
+        }
+    }
+    let ast = ast; // remove mut
 
     let name_pkg = match &*ast.self_ty {
         ::syn::Type::Path(tp) => match tp.path.get_ident() {

bok-macro/src/repos.rs

@@ -236,6 +236,33 @@ pub(crate) fn repo_packages(
     input: TokenStream,
 ) -> TokenStream {
     let local = parse_macro_input!(input as ItemStruct);
+    let mut packages = parse_macro_input!(attrs as crate::PathList);
+
+    // make sure all the packages have generics, and if not add the repo as
+    // generic aka: rewrite
+    //   "#[repo_packages(my::pkg)]" -->> "#[repo_packages(my::pkg<Self>)])"
+    let mut rewrite = false;
+    let repo_argument = {
+        let generic_id: ::syn::Path = ::syn::parse_quote!(id<Self>);
+        generic_id.segments.last().unwrap().arguments.clone()
+    };
+    for p in packages.0.iter_mut() {
+        let last = p.segments.last_mut().unwrap();
+        if last.arguments.is_empty() {
+            rewrite = true;
+            last.arguments = repo_argument.clone();
+        }
+    }
+    if rewrite {
+        let p_list = packages.0.into_iter();
+        return quote! {
+            #[::bok::repo_packages(#(#p_list,)*)]
+            #local
+        }
+        .into();
+    }
+    let packages = packages; // remove mut
+
     let local_attrs = local.attrs.iter();
     let (_, generics, where_clause) = local.generics.split_for_impl();
     let ident = local.ident;
@@ -292,8 +319,6 @@ pub(crate) fn repo_packages(
         })
         .collect::<Vec<&::syn::Field>>();
 
-    let packages = parse_macro_input!(attrs as crate::PathList);
-
     // the packages added manually must not be repeated manually.
     // but they will override any other package added by
     // extending the repository

bok-utils/src/repos/mod.rs

@@ -30,7 +30,7 @@ use ::bok::repository;
 ///
 /// Base repository with some packages
 #[::bok::repository(::bok::RepositoryEmpty)]
-#[::bok::repo_packages(pkgs::one::One<Self>)]
+#[::bok::repo_packages(pkgs::one::One)]
 #[derive(::std::default::Default)]
 pub struct Pkgs1 {
     r1: i32,
@@ -42,7 +42,7 @@ impl Pkgs1 {}
 ///
 /// This repository extends and changes Pkgs1
 #[::bok::repository(Pkgs1)]
-#[::bok::repo_packages(pkgs::two::Two<Self>)]
+#[::bok::repo_packages(pkgs::two::Two)]
 #[derive(::std::default::Default)]
 pub struct Pkgs2 {
     r2: i32,

bok-utils/src/repos/pkgs/one.rs

@@ -15,8 +15,6 @@
  * limitations under the License.
  */
 
-use ::bok::package;
-
 /// Example package
 /// Automatically implements `.builder().my_attr(42).build()` pattern
 #[::bok::package(::bok::PkgEmpty)]
@@ -25,10 +23,8 @@ pub struct One {
     pub my_attr: u32,
 }
 
-impl<R> ::std::default::Default for One<R>
-where
-    R: ::bok::Repository,
-{
+#[::bok::package_impl]
+impl ::std::default::Default for One {
     fn default() -> Self {
         One {
             _bok_base: ::std::marker::PhantomData::default(),

bok-utils/src/repos/pkgs/three.rs

@@ -15,11 +15,9 @@
  * limitations under the License.
  */
 
-use ::bok::package;
-
 /// Example package
 #[::bok::package(::bok::PkgEmpty)]
-#[::bok::deps_build(super::One<R>)]
+#[::bok::deps_build(super::One)]
 pub struct Three {
     pub my_attr: u32,
 }

bok-utils/src/repos/pkgs/two.rs

@@ -15,11 +15,9 @@
  * limitations under the License.
  */
 
-use ::bok::package;
-
 /// Example package
-#[::bok::package(super::one::One<R>)]
-#[::bok::deps_build(super::one::One<R>)]
+#[::bok::package(super::one::One)]
+#[::bok::deps_build(super::one::One)]
 pub struct Two {
     pub my_attr2: u32,
 }