From: Ron M <rm_rails@...>
Date: 2005-12-29T19:43:56+09:00
Subject: Re: What is the difference between :foo and "foo" ?

ara.t.howard@noaa.gov wrote:
> 
> also, don't forget that symbols are __never__ freed.
> this is a severe memory leak:
> 
>   loop{ Time::now.to_f.to_s.intern }

I still wonder if the lack of garbage collection of symbols
is merely a weakness in the current implementation, or something
that's part of the Ruby language.

Note that most lisps and javas can garbage collect
symbols and interned strings.


If it's just an implementation misfeature I'd love to
see that limitation go away in YARV.





Notes:
*1 http://community.schemewiki.org/?scheme-faq-language "Most Schemes
    do perform garbage-collection of symbols, since otherwise programs
    using string->symbol to dynamically create symbols would consume
    ever increasing amounts of memory even if the created symbols are
    no longer being used."

*2 http://mindprod.com/jgloss/interned.html "In the early JDKs, any
    string you interned could never be garbage collected because the
    JVM had to keep a reference to in its Hashtable so it could
    check each incoming string to see if it already had it in the
    pool. With JDK 1.2 came weak references. Now unused interned
    strings will be garbage collected."