From: "Einar Jónsson" <einar@...>
Date: 2011-02-28T06:24:49+09:00
Subject: Different content of Symbol.all_symbols between irb and ruby

Hi all,

I'm experimenting with symbols and how they get added to 
Symbol.all_symbols. I wrote the following ruby script (saved as 
symbol_table.rb):

==== begin snippet ====
puts Symbol.all_symbols.size

colors = [:red, :green, :blue]
puts Symbol.all_symbols.size

rgb_values = {:red => 255, :green => 10, :blue => 40}
puts Symbol.all_symbols.size
==== end snippet ====

If I run this using "irb symbol_table.rb" the number of entries 
increases by 4 and then 1 as expected. However when I run it using "ruby 
symbol_table.rb" it number of entries is the same in all three printouts.

I'm assuming that the difference is that "ruby" parses the file prior to 
execution, and thus has already inserted all the symbols into the 
Symbol.all_symbols array. Can anyone confirm this or explain why I'm wrong?

If it matters I'm running:
* ruby 1.8.7 (2010-01-10 patchlevel 249) [i486-linux]
* irb 0.9.5(05/04/13)

Best regards,
Einar