remove treehouse-format crate and collapse everything into src

src/vfs/overlay.rs

@@ -0,0 +1,40 @@
+use std::fmt;
+
+use tracing::instrument;
+
+use super::{entries, Dir, DynDir, Entries, Query, VPath, VPathBuf};
+
+pub struct Overlay {
+    base: DynDir,
+    overlay: DynDir,
+}
+
+impl Overlay {
+    pub fn new(base: DynDir, overlay: DynDir) -> Self {
+        Self { base, overlay }
+    }
+
+    #[instrument("Overlay::dir", skip(self))]
+    fn dir(&self, path: &VPath) -> Vec<VPathBuf> {
+        let mut dir = entries(&self.base, path);
+        dir.append(&mut entries(&self.overlay, path));
+        dir.sort();
+        dir.dedup();
+        dir
+    }
+}
+
+impl Dir for Overlay {
+    fn query(&self, path: &VPath, query: &mut Query) {
+        query.provide(|| Entries(self.dir(path)));
+
+        self.overlay.query(path, query);
+        self.base.query(path, query);
+    }
+}
+
+impl fmt::Debug for Overlay {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "Overlay({:?}, {:?})", self.base, self.overlay)
+    }
+}