Cleanup.

src/compare/macros.rs

@@ -1,16 +1,34 @@
-macro_rules! compare_noop {
-    ($($field:expr),+) => {
-        $(
-        EmacsField::Required(":foo"),
-        compare_identity,
-        impl_compare_noop
-),+
-    };
-}
-
-pub(crate) use compare_noop;
-
-/// Create iterators for ast nodes where it only has to iterate over children
+/// Assert only the listed properties exist on the Emacs AST node and compare their values to the values on the rust AST node.
+///
+/// Example invocation:
+/// ```
+///     if let Some((new_status, new_message)) = compare_properties!(
+///         emacs,
+///         rust,
+///         (
+///             EmacsField::Required(":key"),
+///             |r| Some(r.key),
+///             compare_property_quoted_string
+///         ),
+///         (
+///             EmacsField::Required(":value"),
+///             |r| Some(r.contents),
+///             compare_property_quoted_string
+///         ),
+///         (EmacsField::Required(":pre-blank"), compare_identity, compare_noop)
+///     )? {
+///         this_status = new_status;
+///         message = new_message;
+///     }
+/// ```
+///
+/// Or if the node has no properties aside from :standard-properties, we can still assert that the node has no unexpected properties:
+/// ```
+///     if let Some((new_status, new_message)) = compare_properties!(emacs)? {
+///         this_status = new_status;
+///         message = new_message;
+///     }
+/// ```
 macro_rules! compare_properties {
     ($emacs:expr, $rust:expr, $(($emacs_field:expr, $rust_value_getter:expr, $compare_fn: expr)),+) => {
         {