Module prompt 

Prompt input

Reads the answer to an interactive prompt (the setup wizard, a token selection) from stdin, so that a cancel can stop the read.

In the TUI, a suspend-mode command reads its prompts on the plain terminal. Ctrl-C there must cancel the command and return to the TUI. A blocking read_line cannot be stopped, and a read on another thread would stay behind and take the TUI’s next keys. So the reader waits for input in short steps and checks CANCEL between them. It reads one byte at a time, so it never takes bytes after the newline.

On Windows the console edits the line itself and hands it over whole, so the reader calls ReadConsoleW and waits for the line. Ctrl-C makes that read return empty with ERROR_OPERATION_ABORTED (std retries then, so a read_line would keep waiting); the reader takes it as the cancel.

Outside the TUI nothing sets CANCEL, and the reader acts as read_line does.

Every prompt goes through ask (or pick, for a numbered list). It pauses the progress bars, so a spinner never draws over a question. A question, a list to pick from and the text around a prompt are not data: they go to the diagnostic channel of the Output. So piped data stays clean, and a TUI run keeps only data for Ctrl-Y and save.

Functions

ask_stdin

ask on stdin (cancellable in the TUI). The scope binary’s own prompts use it.

ask_timeout

ask on stdin that waits at most timeout for the answer. Returns None when no answer came in time.