Packet proc macro

Cargo.toml

@@ -1,6 +1,6 @@
 [workspace]
 resolver = "2"
-members = [ "pumpkin-protocol/", "pumpkin-registry/", "pumpkin-world", "pumpkin/"]
+members = [ "pumpkin-macros", "pumpkin-protocol/", "pumpkin-registry/", "pumpkin-world", "pumpkin/"]
 
 [workspace.package]
 version = "0.1.0"

pumpkin-macros/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "pumpkin-macros"
+version.workspace = true
+edition.workspace = true
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1.0.86"
+quote = "1.0.36"
+syn = "2.0.72"

pumpkin-macros/src/lib.rs

@@ -0,0 +1,24 @@
+use proc_macro::TokenStream;
+use quote::quote;
+
+extern crate proc_macro;
+#[proc_macro_attribute]
+pub fn packet(input: TokenStream, item: TokenStream) -> TokenStream {
+    let ast: syn::DeriveInput = syn::parse(item.clone()).unwrap();
+
+    let name = &ast.ident;
+
+    let (impl_generics, ty_generics, _) = ast.generics.split_for_impl();
+
+    let input: proc_macro2::TokenStream = input.into();
+    let item: proc_macro2::TokenStream = item.into();
+
+    let gen = quote! {
+        #item
+        impl #impl_generics crate::bytebuf::packet_id::Packet for #name #ty_generics {
+            const PACKET_ID: i32 = #input;
+        }
+    };
+
+    gen.into()
+}