From: Joost Diepenmaat <joost@...>
Date: 2008-08-18T19:21:43+09:00
Subject: Re: Immutable, Interned strings??

Mayuresh Kathe <kathe.mayuresh@gmail.com> writes:

> What is the meaning of immutable, interned strings?
> Would like to know in common, general English :-)

"immutable" means "unchangeable" - you cannot change the value of a
symbol. "interned" means (vaguely) that all symbols with the same name
refer to the same symbol value, more or less like a global constant.

IOW, the symbol :this will always refer to the same object anywhere in
your program meaning comparisons between symbols can be done using
very efficient pointer comparisons instead of comparing each character
of a string, so, for instance:

def is_this?(sym)
  sym === :this;
end

is_this?(:this)    => true

HTH,
Joost.

-- 
Joost Diepenmaat | blog: http://joost.zeekat.nl/ | work: http://zeekat.nl/