Re: Answering an Ada/COBOL Question

[Robert Dewar <robert_dewar@my-deja.com>]

In article <382FA652.A72E4150@concentric.net>,
  Joseph P Vlietstra <joevl@concentric.net> wrote:
> For example, the following decision table:
>         A    B    C
>         T    X    X    Action_1
>         F    T    X    Action_2
>         F    F    T    Action_3
>         F    F    F    Action_4
> can be implemented as:
>         if A then
>             Action_1;
>         elsif B then
>              Action_2;
>         elsif C then
>             Action_3;
>         else
>             Action_4;
>         end if;

But this is a poor implementation because it overspecifies,
precisely by not clearly indicating exactly what the don't
care conditions are. One very serious problem with the
elsif structure is precisely that you don't know if the
ordering is critical or not. When it comes to modifying
the conditions, this lack of information can be problematical.

When we deal with conditions that are not exclusive, this
problem always arises, and is one of the reasons that complex
condiitonals are so hard to deal with in maintenance
programming.


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