Re: [PATCH 13/16] send-email: extract_valid_address use qr// regexes and /o

Jeff King [off-list ref] writes:

...
But we are unnecessarily compiling the sub-regexes each time. Not that
this is probably a performance critical piece of code, but your "/o" is
doing very little, and this is exactly the sort perl wankery that I find
interesting.

Well, isn't the _sole_ point of using qr// to optimize by avoiding
recompilation?  If this is not a performance critical section of the code,
what is the point of this change?

This [PATCH 13/16] and also [PATCH 12/16] rewrite strings using qr// but
the patterns thus compiled are used exactly once before the control leaves
the scope of the variables, so...

It is a different story if the patch instead introduced module-level
global variables to hold a pre-compiled regexp objects, but that is not
what we are seeing here.