feedback

crates/compiler/mono/src/ir.rs

@@ -4939,7 +4939,7 @@ pub fn with_hole<'a>(
                 Err(_) => return runtime_error(env, "Can't update record with improper layout"),
             };
 
-            let single_struct_field = sorted_fields.len() == 1;
+            let single_field_struct = sorted_fields.len() == 1;
 
             // The struct indexing generated by the current context
             let mut current_struct_indexing = Vec::with_capacity_in(sorted_fields.len(), env.arena);
@@ -4962,7 +4962,7 @@ pub fn with_hole<'a>(
 
                         // The struct with a single field is optimized in such a way that replacing later indexing will cause an incorrect IR.
                         // Thus, only insert these struct_indices if there is more than one field in the struct.
-                        if !single_struct_field {
+                        if !single_field_struct {
                             let original_struct_symbol = env.unique_symbol();
                             env.struct_indexing
                                 .insert(record_index, original_struct_symbol);
@@ -4999,7 +4999,7 @@ pub fn with_hole<'a>(
                 _ => arena.alloc([record_layout]),
             };
 
-            if single_struct_field {
+            if single_field_struct {
                 // TODO we can probably special-case this more, skipping the generation of
                 // UpdateExisting
                 let mut stmt = hole.clone();
@@ -5032,9 +5032,7 @@ pub fn with_hole<'a>(
                 let expr = Expr::Struct(new_struct_symbols);
                 let mut stmt = Stmt::Let(assigned, expr, record_layout, hole);
 
-                let it = new_struct_symbols.iter().zip(fields);
-
-                for (new_struct_symbol, what_to_do) in it {
+                for (new_struct_symbol, what_to_do) in new_struct_symbols.iter().zip(fields) {
                     match what_to_do {
                         UpdateExisting(field) => {
                             stmt = assign_to_symbol(
@@ -5047,7 +5045,10 @@ pub fn with_hole<'a>(
                                 stmt,
                             );
                         }
-                        CopyExisting => {}
+                        CopyExisting => {
+                            // When a field is copied, the indexing symbol is already placed in new_struct_symbols
+                            // Thus, we don't need additional logic here.
+                        }
                     }
                 }
 
@@ -7673,19 +7674,10 @@ fn can_reuse_symbol<'a>(
                 Err(_) => unreachable!("Can't access record with improper layout"),
             };
 
-            let index =
-                sorted_fields
-                    .into_iter()
-                    .enumerate()
-                    .find_map(
-                        |(current, (label, _, _))| {
-                            if label == *field {
-                                Some(current)
-                            } else {
-                                None
-                            }
-                        },
-                    );
+            let index = sorted_fields
+                .into_iter()
+                .enumerate()
+                .find_map(|(current, (label, _, _))| (label == *field).then_some(current));
 
             let struct_index = index.expect("field not in its own type");
 
@@ -10069,24 +10061,11 @@ enum Usage {
     Unused,
 }
 
-pub struct UsageTrackingMap<K, V>
-where
-    K: std::cmp::Eq + std::hash::Hash,
-{
+#[derive(Default)]
+pub struct UsageTrackingMap<K, V> {
     map: MutMap<K, (V, Usage)>,
 }
 
-impl<K, V> Default for UsageTrackingMap<K, V>
-where
-    K: std::cmp::Eq + std::hash::Hash,
-{
-    fn default() -> Self {
-        Self {
-            map: MutMap::default(),
-        }
-    }
-}
-
 impl<K, V> UsageTrackingMap<K, V>
 where
     K: std::cmp::Eq + std::hash::Hash,