From abc6d3d087304d45e964b3151ee445f795be1ca9 Mon Sep 17 00:00:00 2001
From: vic1707 <28602203+vic1707@users.noreply.github.com>
Date: Sun, 15 Sep 2024 22:25:59 +0200
Subject: [PATCH] rethink code

---
 src/lib.rs | 82 ++++++++++++++++++++++++------------------------------
 1 file changed, 36 insertions(+), 46 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index bf3fef2..86e8f5e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -10,7 +10,7 @@ use deserialize_impl::DeserializeImpl;
 use utils::tri;
 /* Built-in imports */
 extern crate alloc;
-use alloc::{format, string::ToString};
+use alloc::format;
 /* Dependencies */
 use quote::quote;
 use syn::Data;
@@ -20,62 +20,52 @@ pub fn derive_deserialize_versioned(
     input: proc_macro::TokenStream,
 ) -> proc_macro::TokenStream {
     let derive_input: syn::DeriveInput = syn::parse_macro_input!(input);
-    let derive_attrs = derive_input.attrs.clone();
-    let data_kind = match derive_input.data {
-        Data::Enum(_) => "enum",
-        Data::Struct(_) => "struct",
-        Data::Union(_) => "union",
+
+    let Some(versioning_attr) = derive_input
+        .attrs
+        .iter()
+        .find(|meta| meta.path().is_ident("versioning"))
+    else {
+        return tri!(DeserializeImpl::try_from(derive_input)).into();
     };
-    let data_name = derive_input.ident.to_string();
-    let mut deserialize_impl = tri!(DeserializeImpl::try_from(derive_input));
 
     let Attributes {
         versioning,
         optimistic,
-    } = match derive_attrs
-        .iter()
-        .find(|meta| meta.path().is_ident("versioning"))
-    {
-        // if no `versioning` attribut found
-        // simply return the default serde derived impl.
-        None => return proc_macro::TokenStream::from(deserialize_impl),
-        Some(attr) => tri!(Attributes::try_from(attr)),
+    } = tri!(Attributes::try_from(versioning_attr));
+    let ds_ident = derive_input.ident.clone();
+    let ds_kind_name = match derive_input.data {
+        Data::Enum(_) => "enum",
+        Data::Struct(_) => "struct",
+        Data::Union(_) => "union",
     };
+    let no_match_message =
+        format!("data did not match any version of {ds_kind_name} {ds_ident}.");
 
-    if optimistic {
-        let no_match_message = format!(
-            "data did not match any version of {data_kind} {data_name}"
-        );
-        tri!(deserialize_impl.replace_body(|de_stmts|
-            quote! {{
-                use _serde::__private::de::{Content, ContentRefDeserializer};
-                let __content = Content::deserialize(__deserializer)?;
-                let __deserializer = ContentRefDeserializer::<__D::Error>::new(&__content);
-
-                if let Ok(__ok) = { #(#de_stmts)* } {
-                    return Ok(__ok)
-                }
+    let mut deserialize_impl = tri!(DeserializeImpl::try_from(derive_input));
 
+    tri!(deserialize_impl.replace_body(|de_stmts|{
+        let deserialization = if optimistic {
+            quote! {
+                if let Ok(__ok) = { #(#de_stmts)* } { return Ok(__ok) }
                 #versioning
-
-                return Err(
-                    _serde::de::Error::custom(#no_match_message),
-                );
-            }}
-        ));
-    } else {
-        tri!(deserialize_impl.replace_body(|de_stmts|
-            quote! {{
-                use _serde::__private::de::{Content, ContentRefDeserializer};
-                let __content = Content::deserialize(__deserializer)?;
-                let __deserializer = ContentRefDeserializer::<__D::Error>::new(&__content);
-
+                return Err(_serde::de::Error::custom(#no_match_message));
+            }
+        } else {
+            quote! {
                 #versioning
-
                 #(#de_stmts)*
-            }}
-        ));
-    }
+            }
+        };
+
+        quote! {{
+            use _serde::__private::de::{Content, ContentRefDeserializer};
+            let __content = Content::deserialize(__deserializer)?;
+            let __deserializer = ContentRefDeserializer::<__D::Error>::new(&__content);
+
+            #deserialization
+        }}
+    }));
 
     proc_macro::TokenStream::from(deserialize_impl)
 }