From: Stephen Duncan <stephen.duncan@...>
Date: 2007-07-20T08:35:20+09:00
Subject: Re: RCR? Added syntax for chains that possibly return nil

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Not sure if the existence of features in other languages is generally
considered a good support for RCR's, but Groovy has this feature:
http://groovy.codehaus.org/Statements#Statements-Safenavigation (though the
syntax can't be borrowed)

-Stephen

On 7/19/07, Stefan Rusterholz <apeiros@gmx.net> 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.
>
> while (line = gets && line.chomp)
> 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?
>
> Regards
> Stefan
>
> --
> Posted via http://www.ruby-forum.com/.
>
>


-- 
Stephen Duncan Jr
www.stephenduncanjr.com

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