From: Nicholas Van Weerdenburg <nick@...>
Date: 2004-07-18T23:42:04+09:00
Subject: Re: other meanings of ( and ) aka Lispy usage

Thanks. The code example is enlightening.

Nick

James Britt wrote:

> 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
>
>
>