diff --git a/schala-codegen/src/lib.rs b/schala-codegen/src/lib.rs
index 2cd08b5..f33eb0c 100644
--- a/schala-codegen/src/lib.rs
+++ b/schala-codegen/src/lib.rs
@@ -52,19 +52,8 @@ fn extract_attribute_list(name: &str, attrs: &Vec<Attribute>) -> Option<Vec<(Ide
   })
 }
 
-#[proc_macro_derive(ProgrammingLanguageInterface, attributes(LanguageName, SourceFileExtension, PipelineSteps, DocMethod))]
-pub fn derive_programming_language_interface(input: TokenStream) -> TokenStream {
-
-  let ast: DeriveInput = syn::parse(input).unwrap();
-  let name = &ast.ident;
-  let attrs = &ast.attrs;
-
-  let language_name: String = extract_attribute_arg_by_name("LanguageName", attrs).expect("LanguageName is required");
-  let file_ext = extract_attribute_arg_by_name("SourceFileExtension", attrs).expect("SourceFileExtension is required");
-  let passes = extract_attribute_list("PipelineSteps", attrs).expect("PipelineSteps are required");
-  let pass_idents = passes.iter().map(|x| x.0.clone());
-
-  let doc_method: Option<proc_macro2::Ident>= find_attr_by_name("DocMethod", attrs).and_then(|attr| {
+fn get_attribute_identifier(attr_name: &str, attrs: &Vec<Attribute>) -> Option<proc_macro2::Ident> {
+  find_attr_by_name(attr_name, attrs).and_then(|attr| {
     let tts = attr.tts.clone().into_iter().collect::<Vec<_>>();
 
     if tts.len() == 2 {
@@ -76,9 +65,22 @@ pub fn derive_programming_language_interface(input: TokenStream) -> TokenStream
     } else {
       None
     }
-  });
+  })
+}
 
-  let doc_method_body = match doc_method {
+#[proc_macro_derive(ProgrammingLanguageInterface,
+  attributes(LanguageName, SourceFileExtension, PipelineSteps, DocMethod))]
+pub fn derive_programming_language_interface(input: TokenStream) -> TokenStream {
+  let ast: DeriveInput = syn::parse(input).unwrap();
+  let name = &ast.ident;
+  let attrs = &ast.attrs;
+
+  let language_name: String = extract_attribute_arg_by_name("LanguageName", attrs).expect("LanguageName is required");
+  let file_ext = extract_attribute_arg_by_name("SourceFileExtension", attrs).expect("SourceFileExtension is required");
+  let passes = extract_attribute_list("PipelineSteps", attrs).expect("PipelineSteps are required");
+  let pass_idents = passes.iter().map(|x| x.0.clone());
+
+  let get_doc_impl = match get_attribute_identifier("DocMethod", attrs) {
     None => quote! { },
     Some(method_name) => quote! {
       fn get_doc(&self, commands: &Vec<&str>) -> Option<String> {
@@ -118,7 +120,7 @@ pub fn derive_programming_language_interface(input: TokenStream) -> TokenStream
       fn get_passes(&self) -> Vec<PassDescriptor> {
         vec![ #(#pass_descriptors),* ]
       }
-      #doc_method_body
+      #get_doc_impl
     }
   };