Re: isearch region or thing at point.

[Basil L. Contovounesios]

Ergus <address@hidden> writes:

> Why the region-extract-function is not a normal function?

AIUI, so that it can be set by different modes, etc., similarly to
e.g. indent-line-function.

> Why {when|if|and|...}-let macros are in such a special file and most of
> the code don't use them? What's the problem with them?

Apart from some instability in their API across the last couple of Emacs
releases, there's no problem with them.  They are relatively recent
additions to Emacs, and were added to subr-x as "experimental" utilities
that needn't be preloaded.  Existing code definitely shouldn't be
changed purely for the sake of using them (this is a general convention
not specific to subr-x), and new code can often be written without them.
It's mostly a matter of taste, etc.  Note, however, that the usual macro
caveats also apply to these utilities, e.g. w.r.t. stale
macroexpansions that need recompilation.

Thanks,

-- 
Basil