Re: Restricting input depending on output

Drew McDermott wrote:
>    
>    > Why not introduce a
>    > "select" step that picks one from a list?  Then you could have a sequence
>    > 
>    >     GetPostitCompositionPrerequisites
>    >       
>    >       >out>  availableLocationList_Out
>    >             =availableLocationList_In
>    >              >in>
>    > 
>    >                PickOne
>    > 
>    >                  >out>  selectedLocationList_Out
>    >                        =selectedLocationList_In
>    > 
>    >                           >=> 
>    > 
>    >                               StickPostit
>    > 
>    > You would need two 'sameValues' declarations to make this work.
>    > 
>    >                                              -- Drew McDermott
> 
>    Two problems:
> 
>    . That is shifting the problem from
> 	 (availableLocationList_Out --here--> selectedLocationList_In)
>       to
> 	 (availableLocationList_In --here--> selectedLocationList_Out)
>       despite making the sequence longer.
> 
> The same solution works in both places.

Maybe I coudn't explain the problem well.  With the above bullet I wanted to 
say that the proposed solution shifts the problem of "restricting 
selectedLocationList_In as a subset of availableLocationList_Out" to the 
need "to restrict selectedLocationList_Out as a subset of 
availableLocationList_In" (what you are simply assuming based on the 
human-understandable ID 'PickSome', without giving a machine-checkable 
restriction ).

-- Saied Tazari