Introduce an enum for a separate highlighted src block type.

src/context/src_block.rs

@@ -6,19 +6,38 @@ use crate::intermediate::ISrcBlock;
 
 use super::macros::render;
 
+#[derive(Debug, Serialize)]
+#[serde(untagged)]
+pub(crate) enum RenderSrcBlock {
+    Plain(RenderPlainSrcBlock),
+    Highlighted(RenderHighlightedSrcBlock),
+}
+
 #[derive(Debug, Serialize)]
 #[serde(tag = "type")]
 #[serde(rename = "src_block")]
-pub(crate) struct RenderSrcBlock {
+pub(crate) struct RenderPlainSrcBlock {
+    lines: Vec<String>,
+    language: Option<String>,
+    post_blank: organic::types::PostBlank,
+}
+
+#[derive(Debug, Serialize)]
+#[serde(tag = "type")]
+#[serde(rename = "highlighted_src_block")]
+pub(crate) struct RenderHighlightedSrcBlock {
     lines: Vec<String>,
     language: Option<String>,
     post_blank: organic::types::PostBlank,
 }
 
 render!(RenderSrcBlock, ISrcBlock, original, _render_context, {
-    Ok(RenderSrcBlock {
-        lines: original.lines.clone(),
-        language: original.language.clone(),
-        post_blank: original.post_blank,
-    })
+    match original {
+        ISrcBlock::Plain(plain_src_block) => Ok(RenderSrcBlock::Plain(RenderPlainSrcBlock {
+            lines: plain_src_block.lines.clone(),
+            language: plain_src_block.language.clone(),
+            post_blank: plain_src_block.post_blank,
+        })),
+        ISrcBlock::Highlighted(_) => todo!(),
+    }
 });