terminal: Screen tracks semantic content seen

src/terminal/Screen.zig

@@ -77,6 +77,9 @@ else
 /// Dirty flags for the renderer.
 dirty: Dirty = .{},
 
+/// Packed flags for the screen, internal state.
+flags: Flags = .{},
+
 /// See Terminal.Dirty. This behaves the same way.
 pub const Dirty = packed struct {
     /// Set when the selection is set or unset, regardless of if the
@@ -88,6 +91,17 @@ pub const Dirty = packed struct {
     hyperlink_hover: bool = false,
 };
 
+/// A set of internal state that we pack for memory size.
+pub const Flags = packed struct {
+    /// This is flipped to true when any sort of semantic content is
+    /// seen. In particular, this is set to true only when a `prompt` type
+    /// is ever set on our cursor.
+    ///
+    /// This is used to optimize away semantic content operations if we know
+    /// we've never seen them.
+    semantic_content: bool = false,
+};
+
 /// The cursor position and style.
 pub const Cursor = struct {
     // The x/y position within the active area.
@@ -152,39 +166,6 @@ pub const Cursor = struct {
             alloc.destroy(link);
         }
     }
-
-    /// Modify the semantic content type of the cursor. This should
-    /// be preferred over setting it manually since it handles all the
-    /// proper accounting.
-    pub fn setSemanticContent(self: *Cursor, t: union(enum) {
-        prompt: osc.semantic_prompt.PromptKind,
-        output,
-        input: enum { clear_explicit, clear_eol },
-    }) void {
-        switch (t) {
-            .output => {
-                self.semantic_content = .output;
-                self.semantic_content_clear_eol = false;
-            },
-
-            .input => |clear| {
-                self.semantic_content = .input;
-                self.semantic_content_clear_eol = switch (clear) {
-                    .clear_explicit => false,
-                    .clear_eol => true,
-                };
-            },
-
-            .prompt => |kind| {
-                self.semantic_content = .prompt;
-                self.semantic_content_clear_eol = false;
-                self.page_row.semantic_prompt2 = switch (kind) {
-                    .initial, .right => .prompt,
-                    .continuation, .secondary => .prompt_continuation,
-                };
-            },
-        }
-    }
 };
 
 /// Saved cursor state.
@@ -397,6 +378,7 @@ pub fn reset(self: *Screen) void {
     self.charset = .{};
     self.kitty_keyboard = .{};
     self.protected_mode = .off;
+    self.flags = .{};
     self.clearSelection();
 }
 
@@ -2363,6 +2345,42 @@ pub fn cursorSetHyperlink(self: *Screen) PageList.IncreaseCapacityError!void {
     }
 }
 
+/// Modify the semantic content type of the cursor. This should
+/// be preferred over setting it manually since it handles all the
+/// proper accounting.
+pub fn cursorSetSemanticContent(self: *Screen, t: union(enum) {
+    prompt: osc.semantic_prompt.PromptKind,
+    output,
+    input: enum { clear_explicit, clear_eol },
+}) void {
+    const cursor = &self.cursor;
+
+    switch (t) {
+        .output => {
+            cursor.semantic_content = .output;
+            cursor.semantic_content_clear_eol = false;
+        },
+
+        .input => |clear| {
+            cursor.semantic_content = .input;
+            cursor.semantic_content_clear_eol = switch (clear) {
+                .clear_explicit => false,
+                .clear_eol => true,
+            };
+        },
+
+        .prompt => |kind| {
+            self.flags.semantic_content = true;
+            cursor.semantic_content = .prompt;
+            cursor.semantic_content_clear_eol = false;
+            cursor.page_row.semantic_prompt2 = switch (kind) {
+                .initial, .right => .prompt,
+                .continuation, .secondary => .prompt_continuation,
+            };
+        },
+    }
+}
+
 /// Set the selection to the given selection. If this is a tracked selection
 /// then the screen will take ownership of the selection. If this is untracked
 /// then the screen will convert it to tracked internally. This will automatically
@@ -3874,7 +3892,7 @@ test "Screen eraseRows active partial" {
     }
 }
 
-test "Screen: clearPrompt" {
+test "Screen: clearPrompt single line prompt" {
     const testing = std.testing;
     const alloc = testing.allocator;
 

src/terminal/Terminal.zig

@@ -1077,7 +1077,7 @@ pub fn semanticPrompt(
 
             // "Subsequent text (until a OSC "133;B" or OSC "133;I" command)
             // is a prompt string (as if followed by OSC 133;P;k=i\007)."
-            self.screens.active.cursor.setSemanticContent(.{
+            self.screens.active.cursorSetSemanticContent(.{
                 .prompt = cmd.readOption(.prompt_kind) orelse .initial,
             });
 
@@ -1109,7 +1109,7 @@ pub fn semanticPrompt(
             // The k (kind) option specifies the type of prompt:
             // regular primary prompt (k=i or default),
             // right-side prompts (k=r), or prompts for continuation lines (k=c or k=s).
-            self.screens.active.cursor.setSemanticContent(.{
+            self.screens.active.cursorSetSemanticContent(.{
                 .prompt = cmd.readOption(.prompt_kind) orelse .initial,
             });
         },
@@ -1117,21 +1117,21 @@ pub fn semanticPrompt(
         .end_prompt_start_input => {
             // End of prompt and start of user input, terminated by a OSC
             // "133;C" or another prompt (OSC "133;P").
-            self.screens.active.cursor.setSemanticContent(.{
+            self.screens.active.cursorSetSemanticContent(.{
                 .input = .clear_explicit,
             });
         },
 
         .end_prompt_start_input_terminate_eol => {
             // End of prompt and start of user input, terminated by end-of-line.
-            self.screens.active.cursor.setSemanticContent(.{
+            self.screens.active.cursorSetSemanticContent(.{
                 .input = .clear_eol,
             });
         },
 
         .end_input_start_output => {
             // "End of input, and start of output."
-            self.screens.active.cursor.setSemanticContent(.output);
+            self.screens.active.cursorSetSemanticContent(.output);
         },
 
         .end_command => {
@@ -1139,7 +1139,7 @@ pub fn semanticPrompt(
             // anything. Other terminals appear to do nothing here. I think
             // its reasonable at this point to reset our semantic content
             // state but the spec doesn't really say what to do.
-            self.screens.active.cursor.setSemanticContent(.output);
+            self.screens.active.cursorSetSemanticContent(.output);
         },
     }
 }