From: Robert Klemme <shortcutter@...>
Date: 2011-07-14T16:56:07+09:00
Subject: Re: [ANN] summaryse 1.1.0 Released

On Tue, Jul 12, 2011 at 9:58 PM, Bernard Lambeau <blambeau@gmail.com> wrote:
> summaryse version 1.1.0 has been released!
>
> sudo gem summaryse
>
> After birthday yesterday, I already reached a second milestone. A lot
> of useful features added for fun and profit! Examples are given in the
> changelog exerpt below.
>
> Array#summaryse
>
> * <http://github.com/blambeau/summaryse>
> * <http://rubydoc.info/github/blambeau/summaryse/master/frames>
>
> Summarize arrays with full power. As a side effect, this gem allows merging
> multiple YAML configuration files with power, without sacrifying
> simplicity...
>
> Changes:
>
> # 1.1.0 / 2011.07.12
>
>  * Added a way to register user-defined aggregation functions:
>
>        Summaryse.register(:comma_join) do |ary|
>          ary.join(', ')
>        end
>        [1, 4, 12, 7].summaryse(:comma_join)
>        # => "1, 4, 12, 7"

Personally I'd rather directly use #join - it's short as well and much
clearer what is happening - especially if #register and #summaryse
calls are in separate locations.

>  * Added the ability to specify aggregations on hash keys that are not used
> at
>    all. In this case, the aggregator is called on an empty array.
>
>        [
>          { :size => 12 },
>          { :size => 17 }
>        ].summaryse(:size => :max, :hobbies => lambda{|a| a})
>        # => {:size => 17, :hobbies => []}

I am not sure I understand what this is good for.  Can you provide a
bit more insight?

>  * Added the ability to use objects responding to to_summaryse as
> aggregator
>    functions:
>
>        class Foo
>          def to_summaryse; :sum; end
>        end
>        [1, 2, 3].summaryse(Foo.new)
>        # => 6

Why would I want to do that?  Wouldn't it be much shorter to just use
the constant?

>  * Added the ability to explicitly bypass Hash entries as the result of a
>    computation, by returning Summaryse::BYPASS
>
>        [
>          { :hobbies => [:ruby],  :size => 12 },
>          { :hobbies => [:music], :size => 17 }
>        ].summaryse(:size => :max, :hobbies => lambda{|a|
> Summaryse::BYPASS})
>        # => {:size => 17}

Hm...

Generally I would rather implement those directly.  The reason is
simply that this will reduce component dependencies of my applications
by one.  When weighting using an external component (e.g. a gem) vs.
doing it internally the benefit must be higher than the cost for me.
YMMV though.

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/