From: James Britt <jamesUNDERBARb@...>
Date: 2004-07-18T15:35:45+09:00
Subject: Re: other meanings of ( and ) aka Lispy usage

Nicholas Van Weerdenburg wrote:
> What's the meaning of ()  outside of being function parameter delimiters 
> aka in a Lispy sense?
> e.g.
> (puts "command=" + (command="vi " + filename))

Well, they help define evaluation order for expressions.

Ruby makes few distinctions between statements and expressions. Or,
maybe more precisely, pretty much everything in Ruby is an expression,
and so most things return a value.  (I'm tempted to say that
*everything* returns a value, but I'm not positive about that. Can 
someone clarify this?)

Many of the return values are silently discarded, though you'll see them
if you use irb.

If you tend to chain things together, the parens can help ensure the
execution and evaluation occurs as you intended.

You can also use them to mimic Lisp syntax, then egg people on in a
thread abut Ruby and functional programming. :)


(def cons s1, s2
    "#{s2}#{s1}" end )

(def foo x
   ( cons( ( x ), ("Foo has ") ) ) end )

(def bar y
   ( cons( ( y ), ("Bar has ") ) ) end )

( puts( foo( bar( "baz" ) ) ) )



James