Try to optimize

src/state/editor.rs

@@ -1,3 +1,4 @@
+use std::cell::RefCell;
 use std::ops::RangeInclusive;
 
 use cagire_ratatui::Editor;
@@ -55,6 +56,14 @@ pub struct EditorContext {
     pub selection_anchor: Option<usize>,
     pub copied_steps: Option<CopiedSteps>,
     pub show_stack: bool,
+    pub stack_cache: RefCell<Option<StackCache>>,
+}
+
+#[derive(Clone)]
+pub struct StackCache {
+    pub cursor_line: usize,
+    pub lines_hash: u64,
+    pub result: String,
 }
 
 #[derive(Clone)]
@@ -96,6 +105,7 @@ impl Default for EditorContext {
             selection_anchor: None,
             copied_steps: None,
             show_stack: false,
+            stack_cache: RefCell::new(None),
         }
     }
 }

src/state/mod.rs

@@ -13,7 +13,7 @@ pub mod ui;
 
 pub use audio::{AudioSettings, DeviceKind, EngineSection, Metrics, SettingKind};
 pub use options::{OptionsFocus, OptionsState};
-pub use editor::{CopiedStepData, CopiedSteps, EditorContext, Focus, PatternField, PatternPropsField};
+pub use editor::{CopiedStepData, CopiedSteps, EditorContext, Focus, PatternField, PatternPropsField, StackCache};
 pub use live_keys::LiveKeyState;
 pub use modal::Modal;
 pub use panel::{PanelFocus, PanelState, SidePanel};