Subject: bug#52566: 29.0.50; Wishlist: There should be a print-unreadable-function variable

From: Lars Ingebrigtsen <[email-masked]>
Date: Sat, 22 Jan 2022 15:14:03 +0100

Lars Ingebrigtsen <[email-masked]> writes:

> It should be called from print_vectorlike (and any other places that
> print unreadable objects, but I'm not sure there are any other places),
> and should probably have a signature like
>
> OBJECT PRINTCHARFUN ESCAPEFLAG
>
> If it returns nil, the object should be printed as normal.
>
> This can then be used to implement a `readablep' function (that would
> bind this to a function that signals an error, and then catch that
> error), and also to possibly make an alternative version of prin1 that
> returns whether it printed something unprintable.

This has now been implemented in Emacs 29.  The function interface was
changed a bit, though.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no