From: Andrew Timberlake <andrew@...>
Date: 2009-05-22T20:17:09+09:00
Subject: Re: "consuming" the hash instead of just fetching from it

On Fri, May 22, 2009 at 1:10 PM, Balint Erdi <balint.erdi@gmail.com> wrote:
> Hi,
>
> Deleting (vs. just fetching) the hash key from an options hash that
> was passed in as an argument to the method seems prevalent. I saw it
> in several high-quality OS projects (e.g DataMapper, Rails)
>
> For example:
>
> unless options.delete(:only_path)
>        url << (options.delete(:protocol) || 'http')
>        url << '://' unless url.match("://")
>        ...
> end
>
> I wonder what advantage the above snippet has instead of writing:
>
> unless options[:only_path]
>        url << (options[:protocol] || 'http')
>        url << '://' unless url.match("://")
>        ...
> end
>
> Thank you,
> Balint
>
>

It's usually a good idea to consume the option if you are receiving
options that any methods you will subsequently call, won't need (or
may break when receiving) them.
i.e. options specific for the particular method.

If you are not going to pass the options onto other methods, then
there is nothing wrong with just referencing them.

Andrew Timberlake
http://ramblingsonrails.com

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