Method did_change

src/server.rs:469–520

(&self, params: DidChangeTextDocumentParams)

    }

    async fn did_change(&self, params: DidChangeTextDocumentParams) {
        let uri = params.text_document.uri.to_string();

        if params.content_changes.is_empty() {
            return;
        }

        // Apply incremental edits to the current content.
        // Each change event either has a range (incremental) or replaces
        // the entire document (range is None).
        let text = {
            let open_files = self.open_files.read();
            let mut current = open_files
                .get(&uri)
                .map(|s| s.to_string())
                .unwrap_or_default();
            drop(open_files);

            for change in &params.content_changes {
                if let Some(range) = change.range {
                    let start = crate::util::position_to_byte_offset(&current, range.start);
                    let end = crate::util::position_to_byte_offset(&current, range.end);
                    current.replace_range(start..end, &change.text);
                } else {
                    // Full content replacement (fallback)
                    current = change.text.clone();
                }
            }
            Arc::new(current)
        };

        // Update stored content
        self.open_files
            .write()
            .insert(uri.clone(), Arc::clone(&text));

        // Re-parse and update AST map, use map, and namespace map
        let signature_changed = self.update_ast(&uri, &text);

        // Schedule diagnostics in a background task with debouncing.
        // This returns immediately so that completion, hover, and
        // signature help are never blocked by diagnostic computation.
        self.schedule_diagnostics(uri.clone());

        // When a class signature changed (method/property added,
        // removed, or modified; class renamed; parent changed; etc.)
        // other open files may have stale diagnostics that reference
        // the affected classes.  Queue them all for a re-check.
        if signature_changed {
            self.schedule_diagnostics_for_open_files(&uri);
        }
    }

    async fn did_close(&self, params: DidCloseTextDocumentParams) {
        let uri = params.text_document.uri.to_string();