From: Joel VanderWerf <vjoel@...>
Date: 2007-07-19T11:49:56+09:00
Subject: Re: Symbols

Stephen Cox wrote:
> yeah I figured out symbols were the actual value. But one question, if a 
> symbol is  no longer used what happens to it? Is it released when the 
> procedure it was create in completes?

No. Symbols accumulate forever. They cannot be garbage collected in 
current ruby. A variable whose value is a symbol actually contains a 
number, which is an index into a table, rather than the characters of 
the symbol. Ruby has to ensure that, as long as the program runs, this 
table entry contains the same string:

irb(main):003:0> :a.to_i
=> 14033
irb(main):004:0> 14033.to_sym
=> :a

This is another reason to use strings for most purposes. (Also, strings 
look better in YAML, especially as hash keys.)

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407