scroll_page_fractional keybinding

src/Surface.zig

@@ -2080,6 +2080,15 @@ pub fn performBindingAction(self: *Surface, action: input.Binding.Action) !void
             try self.io_thread.wakeup.notify();
         },
 
+        .scroll_page_fractional => |fraction| {
+            const rows: f32 = @floatFromInt(self.grid_size.rows);
+            const delta: isize = @intFromFloat(@floor(fraction * rows));
+            _ = self.io_thread.mailbox.push(.{
+                .scroll_viewport = .{ .delta = delta },
+            }, .{ .forever = {} });
+            try self.io_thread.wakeup.notify();
+        },
+
         .jump_to_prompt => |delta| {
             _ = self.io_thread.mailbox.push(.{
                 .jump_to_prompt = @intCast(delta),

src/input/Binding.zig

@@ -132,6 +132,14 @@ pub fn parse(input: []const u8) !Binding {
                             break :action @unionInit(Action, field.name, value);
                         },
 
+                        .Float => {
+                            const idx = colonIdx orelse return Error.InvalidFormat;
+                            const param = actionRaw[idx + 1 ..];
+                            const value = std.fmt.parseFloat(field.type, param) catch
+                                return Error.InvalidFormat;
+                            break :action @unionInit(Action, field.name, value);
+                        },
+
                         else => unreachable,
                     },
                 }
@@ -182,6 +190,7 @@ pub const Action = union(enum) {
     scroll_to_bottom: void,
     scroll_page_up: void,
     scroll_page_down: void,
+    scroll_page_fractional: f32,
 
     /// Jump the viewport forward or back by prompt. Positive
     /// number is the number of prompts to jump forward, negative
@@ -448,3 +457,19 @@ test "parse: action with int" {
         try testing.expectEqual(@as(i16, 10), binding.action.jump_to_prompt);
     }
 }
+
+test "parse: action with float" {
+    const testing = std.testing;
+
+    // parameter
+    {
+        const binding = try parse("a=scroll_page_fractional:-0.5");
+        try testing.expect(binding.action == .scroll_page_fractional);
+        try testing.expectEqual(@as(f32, -0.5), binding.action.scroll_page_fractional);
+    }
+    {
+        const binding = try parse("a=scroll_page_fractional:+0.5");
+        try testing.expect(binding.action == .scroll_page_fractional);
+        try testing.expectEqual(@as(f32, 0.5), binding.action.scroll_page_fractional);
+    }
+}