implement erase line (EL) CSI

src/terminal/Parser.zig

@@ -104,7 +104,7 @@ pub fn next(self: *Parser, c: u8) [3]?Action {
         break :effect table[c][@enumToInt(self.state)];
     };
 
-    log.info("next: {x}", .{c});
+    // log.info("next: {x}", .{c});
 
     const next_state = effect.state;
     const action = effect.action;

src/terminal/Terminal.zig

@@ -160,7 +160,7 @@ fn csiDispatch(
                 }
 
                 break :mode @intToEnum(
-                    csi.EraseDisplayMode,
+                    csi.EraseDisplay,
                     action.params[0],
                 );
             },
@@ -170,6 +170,27 @@ fn csiDispatch(
             },
         }),
 
+        // Erase Line
+        'K' => try self.eraseLine(switch (action.params.len) {
+            0 => .right,
+            1 => mode: {
+                // TODO: use meta to get enum max
+                if (action.params[0] > 3) {
+                    log.warn("invalid erase line command: {}", .{action});
+                    return;
+                }
+
+                break :mode @intToEnum(
+                    csi.EraseLine,
+                    action.params[0],
+                );
+            },
+            else => {
+                log.warn("invalid erase line command: {}", .{action});
+                return;
+            },
+        }),
+
         else => log.warn("unimplemented CSI: {}", .{action}),
     }
 }
@@ -229,7 +250,7 @@ pub fn setCursorPosition(self: *Terminal, row: usize, col: usize) !void {
 pub fn eraseDisplay(
     self: *Terminal,
     alloc: Allocator,
-    mode: csi.EraseDisplayMode,
+    mode: csi.EraseDisplay,
 ) !void {
     switch (mode) {
         .complete => {
@@ -240,6 +261,22 @@ pub fn eraseDisplay(
     }
 }
 
+/// Erase the line.
+/// TODO: test
+pub fn eraseLine(
+    self: *Terminal,
+    mode: csi.EraseLine,
+) !void {
+    switch (mode) {
+        .right => {
+            var line = &self.screen.items[self.cursor.y];
+            for (line.items[self.cursor.x..line.items.len]) |*cell|
+                cell.char = 0;
+        },
+        else => @panic("unimplemented"),
+    }
+}
+
 /// Backspace moves the cursor back a column (but not less than 0).
 pub fn backspace(self: *Terminal) void {
     const tracy = trace(@src());

src/terminal/csi.zig

@@ -1,7 +1,15 @@
 // Modes for the ED CSI command.
-pub const EraseDisplayMode = enum(u8) {
+pub const EraseDisplay = enum(u8) {
     below = 0,
     above = 1,
     complete = 2,
     scrollback = 3,
 };
+
+// Modes for the EL CSI command.
+pub const EraseLine = enum(u8) {
+    right = 0,
+    left = 1,
+    complete = 3,
+    right_unless_pending_wrap = 4,
+};