Re: Arrays, slices, case, and ‘in’ strategies

[Mace Ayres <mace.ayres@gmail.com>]

Thanks Simon:  I meant to say that in addition to using the array indices to determine the cell location, the array types, (cell) have a triad property too. It is a fixed constant of course. 
Maybe I could use that some how:  - if gird(3,3).triad = 3 then I am in grid 3 - but I still have to search each of the 9 locations in any triad to see it already has 
an instance of the proposed number to enter.

Better yet, can I somehow select just the cells with .triad = N ( not using the grid indices) and check if any cell with triad = N already have the numb value proposed for entry.
But, at first blush that means searching all 81 locations, cells, if I have not already reduced the search space.

In SQL it might look like .. Select cell.triad as evall from grid
                                                     where eval = N ...
returning a subset (slice) of cells with indices r=1..3 and c=1..3