From: "ara.t.howard" <ara.t.howard@...>
Date: 2007-07-21T02:24:44+09:00
Subject: Re: RCR? Added syntax for chains that possibly return nil


On Jul 19, 2007, at 7:31 AM, Stefan Rusterholz wrote:

> One type of construct in ruby that somewhat annoys me and IMHO reduces
> readability is working around cases where an intermediate method might
> return nil. Those cases are e.g.

i feel your pain, however i feel that moves towards calling things  
and having the side effect ignored will lead to new classes of subtle  
bugs.  for instance

   path.gsub! File::SEPARATOR, '\\'

returns nil for no sub for a reason: i may be an error if no  
substitution was done...

still, i agree there are cases where i makes sense to chain/ignore

>
> while (line = gets && line.chomp)

while( (line = gets or break).chomp )
end

but i'm just playing devil's advocate there ;-)

> foo = (bar && bar.baz && bar.baz.quuz) || default # bar might be  
> nil, so
> might bar.baz and bar.baz.quuz
>
> There are some more constructs, most of you surely already used such
> stuff or just spread it onto a bit more of lines.
> While all of this is fine, maybe that could be improved. My RCR  
> would be
> to introduce a new syntax besides . for method invocation, which on  
> the
> first nil aborts any further method calls on it and returns nil.
>
> E.g. the above examples would become:
> while line = gets->chomp
> foo = bar->baz->quuz || default
>
> -> was the first best that came to my mind, if you have better ideas,
> please state.
> Unlike e.g. making nil to respond to every method returning self, this
> solution would put the coder in power as to where he cares about  
> getting
> nil (e.g. he wants an exception if foo is nil, so he just writes
> foo.bar, if he doesn't want one, he writes foo->bar) and where he just
> wants to get the nil value back.
>
> Do you think this RCR is worth to make?

it does, but in the meantime we can use something like:

   http://drawohara.tumblr.com/post/6304449



a @ http://drawohara.com/
--
we can deny everything, except that we have the possibility of being  
better. simply reflect on that.
h.h. the 14th dalai lama