From: Logan Capaldo <logancapaldo@...>
Date: 2006-03-27T08:45:26+09:00
Subject: Re: Data Structure for n-dimension values with defaults


On Mar 26, 2006, at 6:28 PM, Phrogz wrote:

> Help! I can't figure out how to store a rather particular set of data.
>
> An object in my system has properties. Each property has a value.
> However, the value of each property can change based on a number of
> "build axes". There are an arbitrary number of orthogonal build axes,
> none of which is more important than another. (However, if it's  
> needed,
> I am happy to impose a particular ordering on them.)
>
> Each build axis has a number of 'notches', or discrete values along  
> the
> axis. In addition to all the notches, there is one special notch named
> "Master". A value set in this notch is a fallback, default value if
> other notches in the axis have no values.
>
> So, for example, assume I'm talking about a Text object. One of it's
> properties is "textString".
> The system has two build axes: "Language" and "Rating".
>
> The "Language" axis has "French", "English", "German", and "Jibbrish"
> notches in addition to the Master notch. The "Rating" axis has "G",
> "PG", "R", and "X" values.
>
> Here's a monospace-font diagram of the values I want to store:
>
>                 -------------------Language-------------------------
>
>                 Master    English      French     German    Jibbrish
>  R    Master    (yell)       -            -        Ach!        -
>  A         G       -        Wow!         Oh!        -          -
>  T        PG       -     Holy Crap!    Merde!       -          -
>  I         R       -     Holy Shit!   Mon Dieu!     -          -
>  N         X     $!@*        -            -        XXX         -
>  G
>
> With the above, the textString property should have a value of "Ach!"
> if the Language axis is set to German and the Rating axis is set to G,
> PG, or R.
>
> If the Rating is set to "X", then the textString should be set to
> "$!@*" regardless of the Language axis setting...except for if the
> Language is set to German, in which case it should be "XXX"
>
> If the Language is set to "Jibbrish", then the value is "(yell)",
> except when the Rating is "X".
>
> If the Rating is set to "PG" and the Language is set to "English",  
> then
> the textString value should be set to "Holy Crap!". And so on for  
> other
> values that are explicitly set for all axis combinations.
>
>
> Hopefully that example is clear enough to show that explicit values  
> win
> over master values.
>
> So, how the heck would you store this sort of information? I mostly
> don't even care about speed.
>
>

An array of hashes? Actually a hash of structs would probably be better

Row = Struct.new(:master, :english, :french, :german, :gibberish)

table = {
                       :G => Row.new('(yell)', nil, nil, 'Ach!', nil),
                       :PG => Row.new(nil, 'Wow!', 'Oh!', nil, nil),
                       :R =>  Row.new(nil, 'Holy Shit!', 'Mon Dieu!',  
nil, nil),
                       :X =>  Row.new('$!@*', nil, nil, 'XXX', nil)
}

def table.get(rating, language)
        res = self[rating].send(language)
         if res.nil?
             self[rating].master
        else
             res
        end
end



irb(main):040:0> table.get(:X, :german)
=> "XXX"
irb(main):041:0> table.get(:X, :english)
=> "$!@*"