keybindings to move windows left or right in the win list

src/cg/10-os.cg

@@ -183,6 +183,38 @@ os =
     newIndex = min (len osState.windows - 1) (osState.wm.focusedIndex + 1);
     { state = state, emit = [focusWindow newIndex] };
 
+  handleMoveLeftEvent = state \
+    idx = osState.wm.focusedIndex;
+    idx == 0
+    | True \ { state = state, emit = [] }
+    | False \ (
+      newIdx = idx - 1;
+      windows = osState.windows;
+      newWindows = [
+        ...take newIdx windows,
+        nth idx windows ~ unwrapOr {},
+        nth newIdx windows ~ unwrapOr {},
+        ...drop (idx + 1) windows
+      ];
+      { state = state, emit = [osState.windows := newWindows, focusWindow newIdx] }
+    );
+
+  handleMoveRightEvent = state \
+    idx = osState.wm.focusedIndex;
+    idx == len osState.windows - 1
+    | True \ { state = state, emit = [] }
+    | False \ (
+      newIdx = idx + 1;
+      windows = osState.windows;
+      newWindows = [
+        ...take idx windows,
+        nth newIdx windows ~ unwrapOr {},
+        nth idx windows ~ unwrapOr {},
+        ...drop (newIdx + 1) windows
+      ];
+      { state = state, emit = [osState.windows := newWindows, focusWindow newIdx] }
+    );
+
   ui.stateful {
     key = "os",
     autoFocus = True,
@@ -192,10 +224,19 @@ os =
     update = state event \ event
       | Key { key = "p", meta = True } \
         { state = state, emit = [openPalette] }
+
+      | Key { key = "ArrowLeft", meta = True, shift = True } \ handleMoveLeftEvent state
+      | Key { key = "h", meta = True, shift = True } \ handleMoveLeftEvent state
+
+      | Key { key = "ArrowRight", meta = True, shift = True } \ handleMoveRightEvent state
+      | Key { key = "l", meta = True, shift = True } \ handleMoveRightEvent state
+
       | Key { key = "ArrowLeft", meta = True } \ handleFocusLeftEvent state
       | Key { key = "h", meta = True } \ handleFocusLeftEvent state
+
       | Key { key = "ArrowRight", meta = True } \ handleFocusRightEvent state
       | Key { key = "l", meta = True } \ handleFocusRightEvent state
+
       | Key { key = "d", meta = True } \
         { state = state, emit = [closeFocusedWindow 0] }
       | Key { key = "f", meta = True } \