I am not sure if this is the right thread (Regex examples!?) for this but I have been quoted for an old post by BangBangO. This post was sent a long time ago, before
I knew there could be better solutions -mostly from Jellby.
tried to emulate nnbsp (narrow non-breaking space
or espace fine
in French) in any book of mine. I just quoted this possibility, which I really find heavy and unelegant
The 90% good solution is to code the nnbsp. ADE 2.0 will take care of it.
The 100% best solution is to code the nnbsp and
to use a font which already supports it.
However, even the 100% best will not avoid you falling apart with inventive Kobo hyphenation display (some attribute this poor showing to Adobe mobile renderer, of this I can't say).
And to get back on the right track, this is the regex I use now to convert nbsp to nnbsp, following French typographic rules.
S: ([«]) | ([;!?»])
R: \1 -;\2
Note: To get it working you need to suppress the - after 8239.