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From: "Jeffrey R. Carter" <spam.not.jrcarter@acm.not.spam.org>
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Subject: Re: Event mechanisms for GUI's
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tmoran@acm.org wrote:
>> There's nothing wrong with case statements. They're very clear and easy
> In small quantity, yes.  But many-branched, nested, case statements with
> a lot of near duplication are not so clear or maintainable.  They are
> a very low abstraction level, computer-centric, device.
>   If This_Window is for showing danger warnings in big red letters to the
> reactor operator, and That_Window is for showing daily power demand over
> the last month, a mouse click in either is similar from a computer-centric
> view, but vastly different in the problem space.  Having This_Window_Type
> objects and That_Window_Type objects as descendants of Basic_Window_Type
> (inheriting what they have in common) makes them different objects, and a
> dispatching call on When_Left_Button_Down(The_Clicked_Window) is in effect
> a succinct abbreviation for a case statement on the type of Window,
> implemented efficiently and without forgetfullness or typing errors,
> automatically by the compiler.

Sacrificing ease of reading for ease of writing.

-- 
Jeff Carter
"My mind is aglow with whirling, transient nodes of
thought, careening through a cosmic vapor of invention."
Blazing Saddles
85