From 53a5734d09f0c588a445e4fcdaa1fd13ca1daf6d Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Thu, 9 Nov 2023 15:14:33 -0800
Subject: [PATCH] terminal: change mask from u256 to StaticBitSet

---
 src/inspector/termio.zig  |  5 ++---
 src/terminal/Terminal.zig |  3 ++-
 src/termio/Exec.zig       | 18 +++++++-----------
 3 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/src/inspector/termio.zig b/src/inspector/termio.zig
index a9a2f5cde..1b9a45581 100644
--- a/src/inspector/termio.zig
+++ b/src/inspector/termio.zig
@@ -241,7 +241,8 @@ pub const VTEvent = struct {
                 try alloc.dupeZ(u8, @tagName(value)),
             ),
 
-            .Union => |u| if (u.tag_type) |Tag| {
+            .Union => |u| {
+                const Tag = u.tag_type orelse @compileError("Unions must have a tag");
                 const tag_name = @tagName(@as(Tag, value));
                 inline for (u.fields) |field| {
                     if (std.mem.eql(u8, field.name, tag_name)) {
@@ -256,8 +257,6 @@ pub const VTEvent = struct {
                         try md.put(key, s);
                     }
                 }
-            } else {
-                @compileError("Unions must have a tag");
             },
 
             else => switch (Value) {
diff --git a/src/terminal/Terminal.zig b/src/terminal/Terminal.zig
index 1ea3c94fc..c5f777006 100644
--- a/src/terminal/Terminal.zig
+++ b/src/terminal/Terminal.zig
@@ -82,8 +82,9 @@ default_palette: color.Palette = color.default,
 /// The color palette to use. The mask indicates which palette indices have been
 /// modified with OSC 4
 color_palette: struct {
+    const Mask = std.StaticBitSet(@typeInfo(color.Palette).Array.len);
     colors: color.Palette = color.default,
-    mask: u256 = 0,
+    mask: Mask = Mask.initEmpty(),
 } = .{},
 
 /// The previous printed character. This is used for the repeat previous
diff --git a/src/termio/Exec.zig b/src/termio/Exec.zig
index 5e2d3c021..03891364f 100644
--- a/src/termio/Exec.zig
+++ b/src/termio/Exec.zig
@@ -2257,7 +2257,7 @@ const StreamHandler = struct {
         switch (kind) {
             .palette => |i| {
                 self.terminal.color_palette.colors[i] = color;
-                self.terminal.color_palette.mask |= @as(u256, 1) << i;
+                self.terminal.color_palette.mask.set(i);
             },
             .foreground => {
                 self.foreground_color = color;
@@ -2287,19 +2287,15 @@ const StreamHandler = struct {
     ) !void {
         switch (kind) {
             .palette => {
-                var mask = self.terminal.color_palette.mask;
-                defer self.terminal.color_palette.mask = mask;
-
+                const mask = &self.terminal.color_palette.mask;
                 if (value.len == 0) {
                     // Find all bit positions in the mask which are set and
                     // reset those indices to the default palette
-                    while (mask != 0) {
-                        // Safe to truncate, mask is non-zero so @ctz can never
-                        // return a u9
-                        const i: u8 = @truncate(@ctz(mask));
+                    var it = mask.iterator(.{});
+                    while (it.next()) |i| {
                         log.warn("Resetting palette color {}", .{i});
                         self.terminal.color_palette.colors[i] = self.terminal.default_palette[i];
-                        mask ^= @as(u256, 1) << i;
+                        mask.unset(i);
                     }
                 } else {
                     var it = std.mem.tokenizeScalar(u8, value, ';');
@@ -2307,9 +2303,9 @@ const StreamHandler = struct {
                         // Skip invalid parameters
                         const i = std.fmt.parseUnsigned(u8, param, 10) catch continue;
                         log.warn("Resetting palette color {}", .{i});
-                        if (mask & (@as(u256, 1) << i) != 0) {
+                        if (mask.isSet(i)) {
                             self.terminal.color_palette.colors[i] = self.terminal.default_palette[i];
-                            mask ^= @as(u256, 1) << i;
+                            mask.unset(i);
                         }
                     }
                 }