feat: Add placeholder parameter to SwitchCoder

Author: paul-gauthier

aider/commands.py

@@ -28,8 +28,9 @@
 
 
 class SwitchCoder(Exception):
-    def __init__(self, **kwargs):
+    def __init__(self, placeholder=None, **kwargs):
         self.kwargs = kwargs
+        self.placeholder = placeholder
 
 
 class Commands:

aider/main.py

@@ -1109,6 +1109,10 @@ def get_io(pretty):
         except SwitchCoder as switch:
             coder.ok_to_warm_cache = False
 
+            # Set the placeholder if provided
+            if hasattr(switch, 'placeholder') and switch.placeholder is not None:
+                io.placeholder = switch.placeholder
+
             kwargs = dict(io=io, from_coder=coder)
             kwargs.update(switch.kwargs)
             if "show_announcements" in kwargs: