Restructure solution

derive/src/attributes/mod.rs

@@ -0,0 +1,2 @@
+mod row;
+pub use row::Row;

derive/src/attributes/row.rs

@@ -0,0 +1,43 @@
+use quote::ToTokens;
+
+pub const ATTRIBUTE_NAME: &str = "row";
+pub const ATTRIBUTE_SYNTAX: &str = "#[row(crate = ...)]";
+
+pub const CRATE_PATH: &str = "crate";
+pub const DEFAULT_CRATE_PATH: &str = "::clickhouse";
+
+pub struct Row {
+    pub crate_path: syn::Path,
+}
+
+impl Default for Row {
+    fn default() -> Self {
+        let default_crate_path = syn::parse_str::<syn::Path>(DEFAULT_CRATE_PATH).unwrap();
+        Self {
+            crate_path: default_crate_path,
+        }
+    }
+}
+
+impl<'a> TryFrom<&'a syn::Attribute> for Row {
+    type Error = &'a syn::Attribute;
+
+    fn try_from(attr: &'a syn::Attribute) -> Result<Self, Self::Error> {
+        if attr.path().is_ident(ATTRIBUTE_NAME) {
+            let row = attr.parse_args::<syn::Expr>().unwrap();
+            let syn::Expr::Assign(syn::ExprAssign { left, right, .. }) = row else {
+                panic!("expected `{}`", ATTRIBUTE_SYNTAX);
+            };
+            if left.to_token_stream().to_string() != CRATE_PATH {
+                panic!("expected `{}`", ATTRIBUTE_SYNTAX);
+            }
+            let syn::Expr::Path(syn::ExprPath { path, .. }) = *right else {
+                panic!("expected `{}`", ATTRIBUTE_SYNTAX);
+            };
+            Ok(Self { crate_path: path })
+        } else {
+            return Err(attr);
+        }
+    }
+}
+

derive/src/lib.rs

@@ -1,46 +1,28 @@
+mod attributes;
+
 use proc_macro2::TokenStream;
-use quote::{quote, ToTokens};
+use quote::quote;
 use serde_derive_internals::{
     attr::{Container, Default as SerdeDefault, Field},
     Ctxt,
 };
 use syn::{parse_macro_input, Data, DataStruct, DeriveInput, Fields};
 
 struct Attributes {
-    crate_path: syn::Path,
+    row: attributes::Row,
 }
 
 impl From<&[syn::Attribute]> for Attributes {
     fn from(attrs: &[syn::Attribute]) -> Self {
-        const ATTRIBUTE_NAME: &str = "row";
-        const ATTRIBUTE_SYNTAX: &str = "#[row(crate = ...)]";
-
-        const CRATE_PATH: &str = "crate";
-        const DEFAULT_CRATE_PATH: &str = "clickhouse";
-
-        let mut crate_name = None;
+        let mut row = None;
         for attr in attrs {
-            if attr.path().is_ident(ATTRIBUTE_NAME) {
-                let row = attr.parse_args::<syn::Expr>().unwrap();
-                let syn::Expr::Assign(syn::ExprAssign { left, right, .. }) = row else {
-                    panic!("expected `{}`", ATTRIBUTE_SYNTAX);
-                };
-                if left.to_token_stream().to_string() != CRATE_PATH {
-                    panic!("expected `{}`", ATTRIBUTE_SYNTAX);
-                }
-                let syn::Expr::Path(syn::ExprPath { path, .. }) = *right else {
-                    panic!("expected `{}`", ATTRIBUTE_SYNTAX);
-                };
-                crate_name = Some(path);
+            if let Ok(r) = attributes::Row::try_from(attr) {
+                row = Some(r);
             }
         }
-        let crate_name = crate_name.unwrap_or_else(|| {
-            syn::Path::from(syn::Ident::new(
-                DEFAULT_CRATE_PATH,
-                proc_macro2::Span::call_site(),
-            ))
-        });
-        Self { crate_path: crate_name }
+        Self {
+            row: row.unwrap_or_default(),
+        }
     }
 }
 
@@ -79,7 +61,9 @@ pub fn row(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
     let input = parse_macro_input!(input as DeriveInput);
 
     let cx = Ctxt::new();
-    let Attributes { crate_path } = Attributes::from(input.attrs.as_slice());
+    let Attributes {
+        row: attributes::Row { crate_path },
+    } = Attributes::from(input.attrs.as_slice());
     let container = Container::from_ast(&cx, &input);
     let name = input.ident;