diff --git a/src/main.rs b/src/main.rs
index 354220f..49fb810 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -17,6 +17,10 @@ use std::rc::Rc;
 use std::io::{ Write, Read, Cursor };
 use std::fs::File;
 
+
+
+//////////////////// Data Layout ////////////////////
+
 #[derive(Serialize, Deserialize, Debug)]
 struct Node {
     pub x: f32,
@@ -45,8 +49,10 @@ impl Board {
     }
 
     pub fn remove_node(&mut self, id: usize) {
+	// We remove this node from the graph, then drop it from each
+	// other nodes edge.
 	self.nodes.remove(&id);
-	for (_, node) in &mut self.nodes {
+	for node in self.nodes.values_mut() {
 	    node.edges.remove(&id);
 	}
     }
@@ -80,25 +86,7 @@ impl Board {
     }
 }
 
-struct AppState {
-    pub board: Board,
-    pub image_raw: Option<DynamicImage>,
-    pub image: Option<PngImage>,
-}
-
-impl AppState {
-    fn new() -> Self {
-	AppState {
-	    board: Board::new(),
-	    image_raw: None,
-	    image: None
-	}
-    }
-}
-
-fn menu_cb(_m: &mut impl MenuExt) {
-    todo!();
-}
+//////////////////// Utility Functions ////////////////////
 
 fn encode_png(image: &DynamicImage) -> Vec<u8> {
     let mut cursor = Cursor::new(Vec::new());
@@ -146,6 +134,28 @@ impl CoordTransformer for frame::Frame {
     }
 }
 
+fn menu_cb(_m: &mut impl MenuExt) {
+    todo!();
+}
+
+//////////////////// App State ////////////////////
+
+struct AppState {
+    pub board: Board,
+    pub image_raw: Option<DynamicImage>,
+    pub image: Option<PngImage>,
+}
+
+impl AppState {
+    fn new() -> Self {
+	AppState {
+	    board: Board::new(),
+	    image_raw: None,
+	    image: None
+	}
+    }
+}
+
 fn main() {
     let app = app::App::default()
 	.with_scheme(app::Scheme::Gtk);
@@ -241,7 +251,7 @@ fn main() {
 	    image.draw(f.x(), f.y(), f.w(), f.h());
 	}
 	let board = &state.board;
-	for (_, node) in &board.nodes {
+	for node in board.nodes.values() {
 	    let (x, y) = f.from_coords(node.x, node.y);
 	    draw_text(&node.name, x, y);
 	}