Hi :) On Sat 16 Jul 2016 13:46, Giedrius Statkevičius <giedriusw...@gmail.com> writes:
> scheme@(guile-user)> (define (sqrt-iter guess x) (new-if (good-enough? guess > x) > guess (sqrt-iter (improve guess x) x))) > scheme@(guile-user)> (sqrt 2) > <unnamed port>:4:42: In procedure good-enough?: > <unnamed port>:4:42: Throw to key `vm-error' with args `(vm-run "VM: Stack What's happening here is that you have a function that uses too much stack. In Guile 2.0 there is a fixed amount of stack. If you exceed that amount, Guile enters a nested REPL at the error: > Entering a new prompt. Type `,bt' for a backtrace or `,q' to continue. > scheme@(guile-user) [1]> (define (sqrt-iter guess x) (new-if (good-enough? > guess > x) guess x)) So you can get a backtrace to see what's on your stack. This repl is in the context of the stack overflow -- so all the frames are still on the stack. There's just a little bit of stack reserved so that you can poke around and see what's going on. You then cause the stack overflow again, when it already overflowed, and at some point Guile detects this and because it can't handle it, it aborts (not segfaults): > zsh: abort (core dumped) guile Ah well. In Guile 2.0 we can't fix this very nicely. There's no corruption here, just a limit that we can't handle. Fortunately we fixed it in 2.2: https://wingolog.org/archives/2014/03/17/stack-overflow My machine is down for maintenance atm, should be back shortly, in the meantime there's https://web.archive.org/web/*/https://wingolog.org/archives/2014/03/17/stack-overflow Anyway. Thanks for the report, it's a limitation in 2.0 that's fixed in 2.2. Cheers, Andy
