Added note about the Win32PipeInput design.

1 files changed, 3 insertions, 0 deletions

diff --git a/prompt_toolkit/input/win32_pipe.py b/prompt_toolkit/input/win32_pipe.py
index 85c609bf..855d08ae 100644
--- a/prompt_toolkit/input/win32_pipe.py
+++ b/prompt_toolkit/input/win32_pipe.py
@@ -31,6 +31,9 @@ class Win32PipeInput(Input):
     def __init__(self):
         # Event (handle) for registering this input in the event loop.
         # This event is set when there is data available to read from the pipe.
+        # Note: We use this approach instead of using a regular pipe, like
+        #       returned from `os.pipe()`, because making such a regular pipe
+        #       non-blocking is tricky and this works really well.
         self._event = create_win32_event()
 
         self._closed = False