Macro generates extension methods

golem-rust-macro/Cargo.toml

@@ -11,6 +11,7 @@ proc-macro = true
 path = "src/lib.rs"
 
 [dependencies]
+heck = "0.5.0"
 proc-macro2 = "1.0.79"
 quote = "1.0.36"
 syn = { version = "2.0.58", features = ["extra-traits", "full", "fold"] }

golem-rust-macro/src/transaction.rs

@@ -12,7 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use heck::ToPascalCase;
 use proc_macro::TokenStream;
+use proc_macro2::Ident;
 
 use quote::quote;
 use syn::punctuated::Punctuated;
@@ -96,7 +98,7 @@ pub fn golem_operation_impl(args: TokenStream, item: TokenStream) -> TokenStream
     fnsig.inputs.insert(
         0,
         parse_quote! {
-            tx: &mut impl golem_rust::Transaction<#err>
+            self
         },
     );
 
@@ -107,19 +109,32 @@ pub fn golem_operation_impl(args: TokenStream, item: TokenStream) -> TokenStream
         _ => panic!("Expected function to have a return type of Result<_, _>"),
     };
 
+    let traitname = Ident::new(
+        &fnsig.ident.to_string().to_pascal_case(),
+        fnsig.ident.span(),
+    );
+
     let result = quote! {
-        #fnsig {
-            tx.execute(
-                golem_rust::#operation(
-                    |#input_pattern| {
-                        #body
-                    },
-                    |#compensation_pattern| {
-                        #compensate(#(#compensation_args), *)
-                    }
-                ),
-                (#(#input_args), *)
-            )
+        #ast
+
+        trait #traitname {
+            #fnsig;
+        }
+
+        impl<T: golem_rust::Transaction<#err>> #traitname for &mut T {
+            #fnsig {
+                self.execute(
+                    golem_rust::#operation(
+                        |#input_pattern| {
+                            #body
+                        },
+                        |#compensation_pattern| {
+                            #compensate(#(#compensation_args), *)
+                        }
+                    ),
+                    (#(#input_args), *)
+                )
+            }
         }
     };
 

golem-rust/src/transaction.rs

@@ -553,8 +553,9 @@ mod macro_tests {
     fn tx_test_1() {
         let result = fallible_transaction(|tx| {
             println!("Executing the annotated function as an operation directly");
-            test_operation(tx, 1, 0.1)?;
-            test_operation_2(tx, 1, 0.1)?;
+            tx.test_operation(1, 0.1)?;
+            tx.test_operation_2(1, 0.1)?;
+
             Ok(11)
         });
 
@@ -567,7 +568,7 @@ mod macro_tests {
     fn tx_test_2() {
         let result = infallible_transaction(|tx| {
             println!("Executing the annotated function as an operation directly");
-            let _ = test_operation(tx, 1, 0.1);
+            let _ = tx.test_operation(1, 0.1);
             11
         });