Use macros for the intermediate to render step.

This is largely to make changing the type signature of these functions easier by significantly reducing the amount of places that duplicates the signature.

src/context/heading.rs

@@ -6,6 +6,7 @@ use crate::config::Config;
 use crate::error::CustomError;
 use crate::intermediate::IHeading;
 
+use super::macros::render;
 use super::RenderDocumentElement;
 use super::RenderObject;
 
@@ -18,16 +19,17 @@ pub(crate) struct RenderHeading {
     children: Vec<RenderDocumentElement>,
 }
 
-impl RenderHeading {
-    pub(crate) fn new(
-        config: &Config,
-        output_directory: &Path,
-        output_file: &Path,
-        heading: &IHeading,
-    ) -> Result<RenderHeading, CustomError> {
+render!(
+    RenderHeading,
+    IHeading,
+    original,
+    config,
+    output_directory,
+    output_file,
+    {
         let title = {
             let mut ret = Vec::new();
-            for obj in heading.title.iter() {
+            for obj in original.title.iter() {
                 ret.push(RenderObject::new(
                     config,
                     output_directory,
@@ -40,7 +42,7 @@ impl RenderHeading {
 
         let children = {
             let mut ret = Vec::new();
-            for obj in heading.children.iter() {
+            for obj in original.children.iter() {
                 ret.push(RenderDocumentElement::new(
                     config,
                     output_directory,
@@ -52,9 +54,9 @@ impl RenderHeading {
         };
 
         Ok(RenderHeading {
-            level: heading.level + 1, // Adding 1 because the page title is going to be h1.
+            level: original.level + 1, // Adding 1 because the page title is going to be h1.
             title,
             children,
         })
     }
-}
+);