Re: Fontification of the interactive prompt string?

[Tassilo Horn <tsdh@gnu.org>]

Marcin Borkowski <mbork@mbork.pl> writes:

Hi Marcin,

> I have an (interactive "cprompt\n") call, and I'd like the prompt to
> list possible characters (they define a few options for my function,
> and I have good reasons to implement it this way and not with C-u
> etc.)  I'd like to have the relevant characters highlighted, like in:
>
> "file: _n_ew, _o_pen, _c_lose"
>
> where the underscores mean that something is e.g. in a different
> color.
>
> Is it possible?

The `interactive' argument may also be a form which reads the arguments
as it sees fit.

,----[ (info "(elisp)Using Interactive") ]
|    • It may be a Lisp expression that is not a string; then it should be
|      a form that is evaluated to get a list of arguments to pass to the
|      command.  Usually this form will call various functions to read
|      input from the user, most often through the minibuffer (*note
|      Minibuffers::) or directly from the keyboard (*note Reading
|      Input::).
`----

> Bonus points if instead of colors the relevant letter might be
> e.g. put in brackets on terminals not supporting colors.

I don't know but I would refrain from trying to test terminal
capabilities from elisp and then act differently.

Bye,
Tassilo