Re: Escaping a string for substitute-command-keys

[Eli Zaretskii]

> Cc: address@hidden
> From: Clément Pit-Claudel <address@hidden>
> Date: Thu, 3 Oct 2019 14:28:43 -0400
> 
> > Is the problem only with quotes?  Or also with other characters?
> 
> Any characters: for example, \\[ should not trigger a replacement.  The use 
> case (displaying warnings and errors as overlays on code) does not require 
> any string transformation, just to display what a tool (such as gcc or 
> python) produced.

Then why do you use APIs that are meant for keys and quoted strings?
Why not format the message yourself?

> Ideally, it would be best to be able to turn off that translation entirely, I 
> think.  I see why it is convenient, but it seems wasteful to mangle a string 
> with escapes only for these escapes to be promptly removed right after.

Format it yourself, and you have that, no?  Or what am I missing?

> That makes sense.  There's an additional problem that I hadn't thought of at 
> first: if I change the help-echo property on my help-echo strings, even 
> though I'll get the right message when mousing over, now things will break 
> for other renderings that do not use substitute-command-keys (in fact, most 
> places that I see in lisp/ do not use substitute-command-keys on help-echo; 
> most importantly, help-at-pt doesn't). 
> 
> In other words, at the moment I can either get "The footer should be: 
> (provide 'xyz)…" in the echo area and "The footer should be: (provide ’xyz)…" 
> when hovering; or "The footer should be: (provide \='xyz)…" in the echo area 
> and "The footer should be: (provide 'xyz)…" when hovering; neither of these 
> are good.

Then don't use help-echo, use child frames instead.

> Should all uses of help-echo be fixed to call substitute-command-keys, and 
> should all code that sets help-echo and doesn't want substitutions changed to 
> escape quotes and backlashes?

I think you are using the wrong APIs for the job you need to do.
These APIs perform the substitutions for a reason: they were all
written for displaying documentation, not arbitrary strings.