fix: resolve proc-macro reserved keyword and trait export issues

Co-authored-by: aider (openai/andrew/openrouter/deepseek/deepseek-chat-v3.1) <aider@aider.chat>

macros/Cargo.toml

@@ -10,3 +10,4 @@ proc-macro = true
 syn = { version = "2.0", features = ["full"] }
 quote = "1.0"
 proc-macro2 = "1.0"
+to_snake_case_trait = { path = "../to_snake_case_trait" }

macros/src/lib.rs

@@ -4,12 +4,6 @@ use proc_macro::TokenStream;
 use quote::quote;
 use syn::{parse_macro_input, Data, DeriveInput};
 
-// First, define the trait that we want to implement.
-// This could also live in a separate, non-proc-macro crate if you wanted.
-pub trait ToSnakeCaseString {
-    fn to_snake_case(&self) -> String;
-}
-
 /// This is the derive macro function.
 /// The `#[proc_macro_derive(ToSnakeCaseString)]` attribute tells the compiler
 /// that this function implements the derive macro for the `ToSnakeCaseString` trait.
@@ -42,9 +36,9 @@ pub fn to_snake_case_string_derive(input: TokenStream) -> TokenStream {
     });
 
     // Generate the full implementation of the trait for the enum
-    let gen = quote! {
+    let generated = quote! {
         // This is the implementation of our custom trait
-        impl ToSnakeCaseString for #name {
+        impl to_snake_case_trait::ToSnakeCaseString for #name {
             // This is the implementation of the trait's method
             fn to_snake_case(&self) -> String {
                 match self {
@@ -69,7 +63,7 @@ pub fn to_snake_case_string_derive(input: TokenStream) -> TokenStream {
     };
 
     // Return the generated code as a TokenStream
-    gen.into()
+    generated.into()
 }
 
 /// Helper function to convert a PascalCase string to a snake_case string.