feat(search): add Alt+C case-insensitive toggle

CHANGELOG.md

@@ -6,6 +6,7 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 ## [Unreleased]
 
 ### Added
+- add Alt+C in search to toggle case-insensitive matching
 - add `--maximized` and `--fullscreen` flags to start the window in that mode
 - persist and restore window size, maximized, and fullscreen state per session
 - REP (`CSI Ps b`): repeat the last printed character `Ps` times

README.md

@@ -301,6 +301,7 @@ visual_bell = true   # default: false
 | `Enter` | Next match |
 | `↑` / `↓` | Navigate search history |
 | `Ctrl+C` | Copy current match |
+| `Alt+C` | Toggle case-insensitive matching |
 | `n` / `N` | Next / previous match (Normal mode) |
 | `Escape` | Exit search |
 

doc/SPEC.md

@@ -183,6 +183,7 @@ Screenshot capture is a two-step flow: region selection followed by a name promp
 - `Enter` — navigate to the next match (wraps around).
 - `Escape` — return to Normal mode; matches remain visible for `n`/`N` navigation.
 - `Backspace` — delete the last character of the query.
+- `Alt+C` — toggle case-insensitive matching; matches recompute live and the status bar shows `[i]` while active.
 - `n` (Normal mode) — next match.
 - `N` (Normal mode) — previous match.
 - The view scrolls automatically to center the current match.

src/app_event.rs

@@ -121,6 +121,13 @@ impl App {
                 };
                 self.update_search_matches();
             }
+            Key::Character(s)
+                if self.modifiers.state().alt_key() && s.eq_ignore_ascii_case("c") =>
+            {
+                // Alt+C toggles case-insensitive matching and recomputes live.
+                self.state.search_case_insensitive = !self.state.search_case_insensitive;
+                self.update_search_matches();
+            }
             Key::Character(s) if s == "\x03" || s == "c" => {
                 self.copy_current_match();
             }
@@ -234,7 +241,8 @@ impl App {
         if let Some(entry) = self.state.tabs[tab_idx].panes.get(&active)
             && let Some(grid) = entry.pane.grid_read()
         {
-            self.state.search_matches = search::compute_search_matches(&grid, &query);
+            self.state.search_matches =
+                search::compute_search_matches(&grid, &query, self.state.search_case_insensitive);
         }
 
         if !self.state.search_matches.is_empty() {

src/app_state.rs

@@ -97,6 +97,8 @@ pub struct AppState {
     pub search_current: usize,
     pub search_history: Vec<String>,
     pub search_before_history: String,
+    /// When true, scrollback search matching ignores case (toggled with Alt+C).
+    pub search_case_insensitive: bool,
     pub hovered_url: Option<String>,
     pub swallow_next_tab: bool,
     pub theme: ResolvedTheme,
@@ -129,6 +131,7 @@ impl AppState {
             search_current: 0,
             search_history: Vec::new(),
             search_before_history: String::new(),
+            search_case_insensitive: false,
             hovered_url: None,
             swallow_next_tab: false,
             theme,
@@ -244,7 +247,8 @@ impl AppState {
         if let Some(entry) = self.tabs[tab_idx].panes.get(&active)
             && let Some(grid) = entry.pane.grid_read()
         {
-            self.search_matches = crate::search::compute_search_matches(&grid, &query);
+            self.search_matches =
+                crate::search::compute_search_matches(&grid, &query, self.search_case_insensitive);
         }
         if !self.search_matches.is_empty() {
             self.scroll_to_match(0);

src/app_state_test.rs

@@ -620,6 +620,32 @@ fn update_search_matches_finds_content() {
     assert!(!s.search_matches.is_empty());
 }
 
+#[test]
+fn toggling_case_insensitive_changes_match_count() {
+    let mut s = make_state_with_pane();
+    let active = s.tab().active;
+    if let Some(e) = s.tab_mut().panes.get_mut(&active) {
+        for c in "Needle needle NEEDLE".chars() {
+            e.pane.grid.write().unwrap().write_char(c);
+        }
+    }
+    s.tab_mut().mode = InputMode::Search {
+        query: "needle".to_string(),
+        history_pos: None,
+    };
+
+    // Case-sensitive (default): only the exact lowercase "needle" matches.
+    s.update_search_matches();
+    let sensitive = s.search_matches.len();
+    assert_eq!(sensitive, 1);
+
+    // Flip the flag and recompute: all three case variants match.
+    s.search_case_insensitive = true;
+    s.update_search_matches();
+    assert!(s.search_matches.len() > sensitive);
+    assert_eq!(s.search_matches.len(), 3);
+}
+
 /// Poison the active pane's grid lock (simulating a parser thread that panicked
 /// while holding the write lock) and confirm the main-thread read paths degrade
 /// instead of panicking in cascade. Before the poison-tolerant `grid_read`

src/renderer/render_ops.rs

@@ -237,6 +237,7 @@ impl App {
                 &tab_titles,
                 self.state.search_matches.len(),
                 self.state.search_current,
+                self.state.search_case_insensitive,
                 right_text.as_deref(),
                 pane_title,
                 self.state.config.window.inactive_dim,

src/renderer/text.rs

@@ -165,6 +165,7 @@ impl Renderer {
         tab_titles: &[(String, bool, bool)],
         search_total: usize,
         search_current: usize,
+        search_case_insensitive: bool,
         right_text: Option<&str>,
         pane_title: Option<&str>,
         inactive_dim: f32,
@@ -221,6 +222,7 @@ impl Renderer {
             passthrough,
             search_total,
             search_current,
+            search_case_insensitive,
             right_text,
             pane_title,
             bell_flash_intensity.is_some(),
@@ -715,6 +717,7 @@ impl Renderer {
         passthrough: bool,
         search_total: usize,
         search_current: usize,
+        search_case_insensitive: bool,
         right_text: Option<&str>,
         pane_title: Option<&str>,
         bell_active: bool,
@@ -768,6 +771,7 @@ impl Renderer {
             mode,
             search_total,
             search_current,
+            search_case_insensitive,
             badge_x + badge_w + 10,
             badge_y + 2,
             px,
@@ -898,18 +902,20 @@ impl Renderer {
         mode: &InputMode,
         search_total: usize,
         search_current: usize,
+        case_insensitive: bool,
         x: u32,
         y: u32,
         px: f32,
         color: u32,
     ) {
         if let InputMode::Search { query, history_pos } = mode {
+            let ci = if case_insensitive { "  [i]" } else { "" };
             let base = if query.is_empty() {
-                "/".to_string()
+                format!("/{ci}")
             } else if search_total == 0 {
-                format!("/{query}  [no matches]")
+                format!("/{query}  [no matches]{ci}")
             } else {
-                format!("/{query}  [{}/{}]", search_current + 1, search_total)
+                format!("/{query}  [{}/{}]{ci}", search_current + 1, search_total)
             };
             let info = if let Some((pos, len)) = history_pos {
                 format!("{base}  [hist {}/{}]", pos + 1, len)

src/renderer/text_test.rs

@@ -180,6 +180,7 @@ fn draw_empty_buffer_does_not_panic() {
         &[],
         0,
         0,
+        false,
         None,
         None,
         0.55,
@@ -225,6 +226,7 @@ fn draw_pane_fills_background_color() {
         &[("shell".to_string(), true, false)],
         0,
         0,
+        false,
         None,
         None,
         0.55,
@@ -258,6 +260,7 @@ fn draw_tab_bar_renders_without_panic() {
         ],
         0,
         0,
+        false,
         None,
         None,
         0.55,
@@ -290,6 +293,7 @@ fn draw_status_bar_renders_without_panic() {
         &[],
         3,
         1,
+        false,
         Some("/home/user"),
         None,
         0.55,
@@ -320,6 +324,7 @@ fn draw_status_bar_shell_indicators_render_without_panic() {
         &[],
         0,
         0,
+        false,
         None,
         None,
         0.55,
@@ -353,6 +358,7 @@ fn draw_status_bar_pane_title_centered() {
         &[],
         0,
         0,
+        false,
         None,
         Some("nvim src/main.rs"),
         0.55,
@@ -377,6 +383,7 @@ fn draw_status_bar_pane_title_centered() {
         &[],
         0,
         0,
+        false,
         None,
         None,
         0.55,
@@ -416,6 +423,7 @@ fn draw_status_bar_pane_title_suppressed_in_search() {
         &[],
         0,
         0,
+        false,
         None,
         Some("nvim src/main.rs"),
         0.55,
@@ -443,6 +451,7 @@ fn draw_status_bar_pane_title_suppressed_in_search() {
         &[],
         0,
         0,
+        false,
         None,
         None,
         0.55,
@@ -504,6 +513,7 @@ fn draw_with_bell_flash_does_not_panic() {
         &[],
         0,
         0,
+        false,
         None,
         None,
         0.55,
@@ -534,6 +544,7 @@ fn draw_with_separator_does_not_panic() {
         &[],
         0,
         0,
+        false,
         None,
         None,
         0.55,
@@ -633,6 +644,7 @@ fn do_draw(r: &mut Renderer, panes: &[PaneView<'_>], mode: &InputMode) {
         &[("t".to_string(), true, false)],
         0,
         0,
+        false,
         None,
         None,
         0.55,
@@ -803,6 +815,7 @@ fn draw_pane_osc8_link_paints_underline_without_hover() {
         &[("t".to_string(), true, false)],
         0,
         0,
+        false,
         None,
         None,
         0.55,
@@ -897,6 +910,7 @@ fn draw_pane_reverse_video_swaps_background_to_fg_color() {
         &[("t".to_string(), true, false)],
         0,
         0,
+        false,
         None,
         None,
         0.55,
@@ -1126,6 +1140,7 @@ fn draw_status_bar_search_empty_query_shows_slash() {
         &[],
         0,
         0,
+        false,
         None,
         None,
         0.55,
@@ -1159,6 +1174,7 @@ fn draw_status_bar_search_no_matches_shows_label() {
         &[],
         0, // search_total = 0
         0,
+        false,
         None,
         None,
         0.55,
@@ -1337,6 +1353,7 @@ fn pane_padding_leaves_top_left_corner_as_background() {
         &[("t".to_string(), true, false)],
         0,
         0,
+        false,
         None,
         None,
         0.55,

src/search.rs

@@ -2,12 +2,20 @@ use crate::terminal::grid::Grid;
 
 /// Scans `grid` (scrollback + live rows) for all matches of `query` (treated as a regex).
 /// Returns `(abs_row, start_col, match_len)` tuples sorted by ascending `abs_row`.
+/// When `case_insensitive` is true, matching ignores case.
 /// Returns an empty vec when `query` is empty or not a valid regex.
-pub fn compute_search_matches(grid: &Grid, query: &str) -> Vec<(usize, usize, usize)> {
+pub fn compute_search_matches(
+    grid: &Grid,
+    query: &str,
+    case_insensitive: bool,
+) -> Vec<(usize, usize, usize)> {
     if query.is_empty() {
         return Vec::new();
     }
-    let re = match regex::Regex::new(query) {
+    let re = match regex::RegexBuilder::new(query)
+        .case_insensitive(case_insensitive)
+        .build()
+    {
         Ok(r) => r,
         Err(_) => return Vec::new(),
     };