Use macros for creating the intermediate stage.

This is to make it easier to change function signatures by consolidating the places where the signatures exist.

src/intermediate/section.rs

@@ -1,26 +1,21 @@
-use crate::error::CustomError;
-
+use super::macros::intermediate;
 use super::registry::Registry;
 use super::IElement;
+use crate::error::CustomError;
 
 #[derive(Debug, Clone)]
 pub(crate) struct ISection {
     pub(crate) children: Vec<IElement>,
 }
 
-impl ISection {
-    pub(crate) async fn new<'b, 'parse>(
-        registry: &'b mut Registry<'parse>,
-        section: &'b organic::types::Section<'parse>,
-    ) -> Result<ISection, CustomError> {
-        let children = {
-            let mut ret = Vec::new();
-            for elem in section.children.iter() {
-                ret.push(IElement::new(registry, elem).await?);
-            }
-            ret
-        };
+intermediate!(ISection, Section, |registry, original| async {
+    let children = {
+        let mut ret = Vec::new();
+        for elem in original.children.iter() {
+            ret.push(IElement::new(registry, elem).await?);
+        }
+        ret
+    };
 
-        Ok(ISection { children })
-    }
-}
+    Ok(ISection { children })
+});