WIP improvise-km71: edit a formula from the panel

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdfEGXA7aJ6ftMsCc9PJze

crates/improvise-command/src/command/cmd/commit.rs

@@ -1,5 +1,7 @@
+use crate::formula::FormulaId;
 use crate::model::category::MEASURE_CATEGORY;
 use crate::model::cell::CellKey;
+use crate::protocol::FormulaSlot;
 use crate::ui::app::AppMode;
 use crate::ui::effect::{self, Effect};
 use crate::view::RecordCol;
@@ -806,6 +808,12 @@ impl Cmd for CommitAndAdvance {
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum CommitKind {
     Formula,
+    /// Edit the formula the editor was opened on, read off
+    /// [`AppMode::FormulaEdit`]'s slot at construction (improvise-km71).
+    ReplaceFormula {
+        id: FormulaId,
+        was: String,
+    },
     Category,
     /// Add an item to this category, resolved from [`AppMode::ItemAdd`] at
     /// construction so `execute` stays pure over the kind and its buffer.
@@ -814,10 +822,20 @@ pub enum CommitKind {
     },
 }
 
-/// Resolve a `commit-buffer` argument against the current mode. Only `Item` needs
-/// the mode, so a script line can still build the other two.
+/// Resolve a `commit-buffer` argument against the current mode. `Item` and a
+/// formula edit need the mode, so a script line can build only the others.
 pub fn parse_commit_kind(arg: &str, mode: &AppMode) -> Result<CommitKind, String> {
     match (arg, mode) {
+        (
+            "formula",
+            AppMode::FormulaEdit {
+                slot: FormulaSlot::Existing { id, was },
+                ..
+            },
+        ) => Ok(CommitKind::ReplaceFormula {
+            id: id.clone(),
+            was: was.clone(),
+        }),
         ("formula", _) => Ok(CommitKind::Formula),
         ("category", _) => Ok(CommitKind::Category),
         ("item", AppMode::ItemAdd { category, .. }) => Ok(CommitKind::Item {
@@ -832,7 +850,7 @@ impl CommitKind {
     /// The minibuffer this kind consumes.
     pub fn buffer(&self) -> &'static str {
         match self {
-            Self::Formula => "formula",
+            Self::Formula | Self::ReplaceFormula { .. } => "formula",
             Self::Category => "category",
             Self::Item { .. } => "item",
         }
@@ -842,7 +860,7 @@ impl CommitKind {
     /// minibuffer.
     fn on_empty(&self) -> AppMode {
         match self {
-            Self::Formula => AppMode::FormulaPanel,
+            Self::Formula | Self::ReplaceFormula { .. } => AppMode::FormulaPanel,
             Self::Category | Self::Item { .. } => AppMode::CategoryPanel,
         }
     }
@@ -851,7 +869,7 @@ impl CommitKind {
     /// categories and items are entered in batches, formulas are not.
     fn on_commit(&self) -> Option<AppMode> {
         match self {
-            Self::Formula => Some(AppMode::FormulaPanel),
+            Self::Formula | Self::ReplaceFormula { .. } => Some(AppMode::FormulaPanel),
             Self::Category | Self::Item { .. } => None,
         }
     }
@@ -859,6 +877,7 @@ impl CommitKind {
     fn status(&self, name: &str) -> String {
         match self {
             Self::Formula => "Formula added".to_string(),
+            Self::ReplaceFormula { .. } => "Formula updated".to_string(),
             Self::Category => format!("Added category \"{name}\""),
             Self::Item { .. } => format!("Added \"{name}\""),
         }
@@ -872,6 +891,11 @@ impl CommitKind {
                 raw: name.to_string(),
                 target_category: "_Measure".to_string(),
             }),
+            Self::ReplaceFormula { id, was } => Box::new(effect::ReplaceFormula {
+                id: id.clone(),
+                was: was.clone(),
+                raw: name.to_string(),
+            }),
             Self::Category => Box::new(effect::AddCategory(name.to_string())),
             Self::Item { category } => Box::new(effect::AddItem {
                 category: category.clone(),