Re: [Emacs-diffs] master 9ce1d38: Use curved quotes in core elisp diagnostics

[Paul Eggert]

Stefan Monnier wrote:

> IOW, we don't need format-message at all.  Instead we can just have
> a "prettify" function which can be used on the output of `format' (or on
> any other string we like) and which uses some heuristic to turn `...'
> into its ‘...’ equivalent.

I had already put something along those lines in master (the prettify function's 
name was ‘internal--text-restyle’), but despite hacking around with it for a 
while I didn’t find a good independent use for it.

Every use was of the form (format (prettify STRING) ARGS).  The prettify 
function wasn't useful as postpass to ‘format’ because that would have typically 
mishandled examples like (prettify (format "Invalid `%s'" xxx)) where XXX 
contains quotes.  Nor was it useful as a prepass or postpass to 
‘substitute-command-keys’, for similar reasons.

Plus, even with prettify split out, we need a format-message function anyway, if 
only as a convenience, because it's so often needed in examples like (apply 
#'format-message fmt args).  Since there was a demonstrated need for 
format-message but not for prettify (and before reading your abovequoted email) 
I redid the code to export the former and not the latter.  The new 
implementation avoids burdening the GC with two copies of the string, which is a 
minor performance win.

If there's a use case for the prettify function I'll be happy to resurrect it, 
of course.