Andy Wingo <wi...@pobox.com> skribis: > On Fri 31 Mar 2017 23:41, l...@gnu.org (Ludovic Courtès) writes: > >> Andy Wingo <wi...@pobox.com> skribis: >> >>> On Fri 31 Mar 2017 13:33, l...@gnu.org (Ludovic Courtès) writes: >> >> [...] >> >>>>> ;; These can only form part of a safe binding set if no mutable >>>>> ;; pair is exposed to the sandbox. >>>>> (define *mutating-pair-bindings* >>>>> '(((guile) >>>>> set-car! >>>>> set-cdr!))) >>>> >>>> When used on a literal pair (mapped read-only), these can cause a >>>> segfault. Now since the code is ‘eval’d, the only literal pairs it can >>>> see are those passed by the caller I suppose, so this may be safe? >>> >>> Who knows. I mean vector-set! can also cause segfaults. I think we >>> should fix that situation to throw an exception. >> >> Yes, that would be nice, though I suppose it’s currently tricky to >> achieve no? Maybe that newfangled ‘userfaultfd’ will save us all. > > Maybe :) I mean it's possible now to catch SIGSEGV. I just sent a > patch to guile-devel; wdyt? Needs docs & tests of course.
Neat! I’ll look into it. >>>>> (define *all-pure-and-impure-bindings* >>>>> (append *all-pure-bindings* >>>> >>>> Last but not least: why all the stars? :-) >>>> I’m used to ‘%something’. >>> >>> For me I read % as being pronounced "sys" and indicating internal >>> bindings. Why do you use it for globals? Is it your proposal that we >>> use it for globals? >> >> I tend to do that but I realize I must be a minority here. Let it be >> stars then. :-) > > I think that like you, I learned Scheme conventions in an ad-hoc way, > apeing conventions from many sources (Guile's own code, Common Lisp, > random Scheme). I would be happy if we could be a bit more purposeful > about our conventions and I would be happy to change mine :) % > can work fine :) I grepped Guile and it seems that stars are actually more common for globals than % (I thought it was the opposite but as you say, I kind of discovered/invented the conventions.) Riastradh’s document at <http://mumble.net/~campbell/scheme/style.txt> has this: Affix asterisks to the beginning and end of a globally mutable variable. This allows the reader of the program to recognize very easily that it is badly written! … but it doesn’t say anything about constants nor about %. It could be ‘all-pure-bindings’, or ‘*all-pure-bindings*’, or ‘%all-pure-bindings’. So, dunno, as you see fit! Ludo’.
