GNU Guile 3.0.5
Copyright (C) 1995-2021 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)> #{index-of-#;0}#
^[[A^CWhile compiling expression:
User interrupt
scheme@(guile-user)> #{index-of-#;x0}#
While compiling expression:
no such language tree-il