On Thu, 19 Nov 2020 at 14:51, Stefan Kangas <ste...@marxist.se> wrote:
> Neil Jerram <neiljer...@gmail.com> writes: > > >> I've been working on removing redundant `function' around `lambda' in > >> Emacs core, > > > > I'm slightly curious about the history and reasoning around this. If I > > understand correctly, (lambda ...) on its own has always worked, and it's > > never been strictly necessary to add (quote ...) or (function ...) around > > it. Then sometime (Emacs 19 or later, I think) it started being > > recommended to use (function ...). > > > > Do you know why that recommendation started, and should I understand that > > the reasoning for it has now evaporated? > > Correct, there is no reason to do this. > > I don't know the history here, and there are people on emacs-devel that > would know better. > > I _suspect_ that the byte-compiler first got the capability to optimize > calls to anonymous functions, but that it required to explicitly marked > as such with `function'. Later, it grew the capability to recognize > lambda as such automatically. But I don't know if that is correct; it's > just a guess. In any case, they are no longer needed as lambda and > lambda+function are equivalent. > > (Note that the worst thing here is to do `(quote (lambda ...))' as that > defeats byte-compiler optimizations altogether.) > Many thanks Stefan!
