Re: Are symbols garbage collected?

[Christopher Allan Webber]

Marko Rauhamaa writes:

> Christopher Allan Webber <address@hidden>:
>
>> I thought they weren't but now I'm not really sure where I got that
>> idea from. Does anyone know for sure?
>
> I don't think the language spec says anything about any particular
> object or object type being garbage collected. Symbols are first-class
> objects and undergo the same treatment as any other object.

Yes, though they are intern'ed, and symbols are not always garbage
collected.  I know in Ruby at one point they were not, I heard today
they aren't in Erlang either, and even until apparently recently they
weren't GC'ed in MIT Scheme I think:

https://www.gnu.org/software/mit-scheme/release.html

  "Symbols can now be garbage-collected." in 9.1 even.. that came out in
  2011!

Anyway it looks like Guile does indeed garbage collect symbols.  I have
no idea how I got the impression that it did not, but it looks like it
isn't unusual for symbols to not be GC'ed in a number of languages.