refine macros

patch-db-macro-internals/src/lib.rs

@@ -1,50 +1,77 @@
 use proc_macro2::TokenStream;
 use quote::quote;
 use syn::{
-    AttributeArgs, Fields, Ident, Item, ItemEnum, ItemStruct, Lit, LitStr, Meta, MetaNameValue,
-    NestedMeta, Type,
+    Data, DataEnum, DataStruct, DeriveInput, Fields, Ident, Lit, LitStr, MetaNameValue, Type,
 };
 
-pub fn build_model(attr: &AttributeArgs, item: &Item) -> TokenStream {
+pub fn build_model(item: &DeriveInput) -> TokenStream {
     let mut model_name = None;
-    for arg in attr {
+    for arg in item
+        .attrs
+        .iter()
+        .filter(|attr| attr.path.is_ident("model"))
+        .map(|attr| attr.parse_args::<MetaNameValue>().unwrap())
+    {
         match arg {
-            NestedMeta::Meta(Meta::NameValue(MetaNameValue {
+            MetaNameValue {
                 path,
                 lit: Lit::Str(s),
                 ..
-            })) if path.is_ident("name") => model_name = Some(s.parse().unwrap()),
+            } if path.is_ident("name") => model_name = Some(s.parse().unwrap()),
             _ => (),
         }
     }
-    match item {
-        Item::Struct(struct_ast) => build_model_struct(struct_ast, model_name),
-        Item::Enum(enum_ast) => build_model_enum(enum_ast, model_name),
+    match &item.data {
+        Data::Struct(struct_ast) => build_model_struct(item, struct_ast, model_name),
+        Data::Enum(enum_ast) => build_model_enum(item, enum_ast, model_name),
         _ => panic!("Models can only be created for Structs and Enums"),
     }
 }
 
-fn build_model_struct(ast: &ItemStruct, model_name: Option<Ident>) -> TokenStream {
+fn build_model_struct(
+    base: &DeriveInput,
+    ast: &DataStruct,
+    model_name: Option<Ident>,
+) -> TokenStream {
     let model_name = model_name.unwrap_or_else(|| {
         Ident::new(
-            &format!("{}Model", ast.ident),
+            &format!("{}Model", base.ident),
             proc_macro2::Span::call_site(),
         )
     });
-    let base_name = &ast.ident;
-    let model_vis = &ast.vis;
+    let base_name = &base.ident;
+    let model_vis = &base.vis;
     let mut child_fn_name: Vec<Ident> = Vec::new();
     let mut child_model: Vec<Type> = Vec::new();
     let mut child_path: Vec<LitStr> = Vec::new();
-    let serde_rename_all = todo!();
+    let serde_rename_all = base
+        .attrs
+        .iter()
+        .filter(|attr| attr.path.is_ident("serde"))
+        .filter_map(|attr| attr.parse_args::<MetaNameValue>().ok())
+        .filter(|nv| nv.path.is_ident("rename_all"))
+        .find_map(|nv| match nv.lit {
+            Lit::Str(s) => Some(s.value()),
+            _ => None,
+        });
     match &ast.fields {
         Fields::Named(f) => {
             for field in &f.named {
                 let ident = field.ident.clone().unwrap();
                 child_fn_name.push(ident.clone());
-                child_model.push(field.ty.clone());
-                let serde_rename = todo!();
-                match (serde_rename, serde_rename_all) {
+                let ty = &field.ty;
+                child_model.push(syn::parse2(quote! { patch_db::Model<#ty> }).unwrap()); // TODO: check attr
+                let serde_rename = field
+                    .attrs
+                    .iter()
+                    .filter(|attr| attr.path.is_ident("serde"))
+                    .filter_map(|attr| syn::parse2::<MetaNameValue>(attr.tokens.clone()).ok())
+                    .filter(|nv| nv.path.is_ident("rename"))
+                    .find_map(|nv| match nv.lit {
+                        Lit::Str(s) => Some(s),
+                        _ => None,
+                    });
+                match (serde_rename, serde_rename_all.as_ref().map(|s| s.as_str())) {
                     (Some(a), _) => child_path.push(a),
                     (None, Some("lowercase")) => child_path.push(LitStr::new(
                         &heck::CamelCase::to_camel_case(ident.to_string().as_str()).to_lowercase(),
@@ -78,10 +105,16 @@ fn build_model_struct(ast: &ItemStruct, model_name: Option<Ident>) -> TokenStrea
                 }
             }
         }
-        Fields::Unnamed(f) => {}
+        Fields::Unnamed(f) => {
+            if f.unnamed.len() == 1 {
+            } else if f.unnamed.len() > 1 {
+            }
+            todo!()
+        }
         Fields::Unit => (),
     }
     quote! {
+        #[derive(Debug, Clone)]
         #model_vis struct #model_name(patch_db::Model<#base_name>);
         impl core::ops::Deref for #model_name {
             type Target = patch_db::Model<#base_name>;
@@ -90,6 +123,9 @@ fn build_model_struct(ast: &ItemStruct, model_name: Option<Ident>) -> TokenStrea
             }
         }
         impl #model_name {
+            pub fn new(ptr: json_ptr::JsonPointer) -> Self {
+                #model_name(patch_db::Model::new(ptr))
+            }
             // foreach element, create accessor fn
             #(
                 pub fn #child_fn_name(&self) -> #child_model {
@@ -97,9 +133,12 @@ fn build_model_struct(ast: &ItemStruct, model_name: Option<Ident>) -> TokenStrea
                 }
             )*
         }
+        impl patch_db::HasModel for #base_name {
+            type Model = #model_name;
+        }
     }
 }
 
-fn build_model_enum(ast: &ItemEnum, model_name: Option<Ident>) -> TokenStream {
+fn build_model_enum(base: &DeriveInput, ast: &DataEnum, model_name: Option<Ident>) -> TokenStream {
     todo!()
 }

patch-db-macro/src/lib.rs

@@ -1,13 +1,10 @@
 extern crate proc_macro;
 
 use proc_macro::TokenStream;
-use syn::{parse_macro_input, AttributeArgs, Item};
+use syn::{parse_macro_input, DeriveInput};
 
-#[proc_macro_attribute]
-pub fn model(attr_in: TokenStream, item_in: TokenStream) -> TokenStream {
-    let mut res = proc_macro2::TokenStream::from(item_in.clone());
-    let attr = parse_macro_input!(attr_in as AttributeArgs);
-    let item = parse_macro_input!(item_in as Item);
-    res.extend(patch_db_macro_internals::build_model(&attr, &item));
-    res.into()
+#[proc_macro_derive(HasModel, attributes(model))]
+pub fn model(item: TokenStream) -> TokenStream {
+    let item = parse_macro_input!(item as DeriveInput);
+    patch_db_macro_internals::build_model(&item).into()
 }

patch-db/Cargo.toml

@@ -19,6 +19,7 @@ serde_json = "1.0.61"
 serde_cbor = { path = "../cbor" }
 thiserror = "1.0.23"
 tokio = { version = "1.0.1", features = ["sync", "fs", "rt", "io-util", "macros"] }
+patch-db-macro = { path = "../patch-db-macro" }
 
 [dev-dependencies]
 serde = { version = "1.0.118", features = ["rc", "derive"] }

patch-db/src/lib.rs

@@ -1002,13 +1002,14 @@ impl<T: Serialize + for<'de> Deserialize<'de>> DerefMut for ModelDataMut<T> {
     }
 }
 
+#[derive(Debug)]
 pub struct Model<T: Serialize + for<'de> Deserialize<'de>> {
     ptr: JsonPointer,
     phantom: PhantomData<T>,
 }
 impl<T> Model<T>
 where
-    T: Serialize + for<'de> Deserialize<'de> + Send + Sync + 'static,
+    T: Serialize + for<'de> Deserialize<'de>,
 {
     pub fn new(ptr: JsonPointer) -> Self {
         Self {
@@ -1045,3 +1046,18 @@ where
         }
     }
 }
+impl<T> std::clone::Clone for Model<T>
+where
+    T: Serialize + for<'de> Deserialize<'de>,
+{
+    fn clone(&self) -> Self {
+        Model {
+            ptr: self.ptr.clone(),
+            phantom: PhantomData,
+        }
+    }
+}
+
+pub trait HasModel {
+    type Model;
+}

patch-db/src/test.rs

@@ -1,4 +1,6 @@
 use super::*;
+use crate as patch_db;
+use patch_db_macro::HasModel;
 
 #[tokio::test]
 async fn basic() {
@@ -21,24 +23,15 @@ async fn basic() {
     assert_eq!(get_res, "hello");
 }
 
-#[derive(Debug, serde::Deserialize, serde::Serialize)]
+#[derive(Debug, serde::Deserialize, serde::Serialize, HasModel)]
 pub struct Sample {
     a: String,
+    #[model(name = ChildModel)]
     b: Child,
 }
 
-pub struct SampleModel(Model<Sample>);
-impl core::ops::Deref for SampleModel {
-    type Target = Model<Sample>;
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
 #[derive(Debug, serde::Deserialize, serde::Serialize)]
 pub struct Child {
     a: String,
     b: usize,
 }
-
-pub struct ChildModel(Model<Child>);