Re: Ceate a set (type?) of list of integers that varies at run time

["Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>]

On 01/27/2018 12:58 AM, Mace Ayres wrote:
> * Using the word set in mathetical sense.
> I have an array 2D_array is Integer 1..9, 1..9 of my_record.  — my_record has a boolean field locked.
> Before looping/iteration across 2D_array (r,c), I want to restrict the columns (c) that I process, to bet something  like
> for r in 1..9 loop
>   for c (column) in (columns_to_check)
> 
> I have to create the enumeration type? list of columns to check and put in my columns_to_check container
> and then only iterate these, maybe 1,2,3,7,8,9 — do not check 4,5 or 6
> 
> Need a function like get_columns_to_check
> that iterates all 1..9 columns
> if (r,c).locked is true
> then do not have in final columns_to_check something (range, or enumeration type)
> either add to empty columns_to_check or delete from default columns_to_check that has 1..9;
> 
> what kind, type of an object can I use to hold the valid columns to check thing-e columns_to_check
> and that I can also iterate across.
> 
> Can I have a range that is not a continuous series of integers, NOT 1..9 but 1,2,5,6,7,9
> and then some different subset of 1..9 the next time. Recalculating a new set Columns_to_check for each outer loop of rows?

Is there some reason you can't do something like

type Column_Set is array (Column_Number) of Boolean;

Checkable : Column_Set;

for C in Checkable'range loop
    -- set Checkable (C)
end loop;

for R in A'range (1) loop
    for C in A'range (2) loop
       if Checkable (C) then
          -- do something with A (R, C)
       end if;
    end loop;
end loop;

-- 
Jeff Carter
"Mr. President, we must not allow a mine-shaft gap!"
Dr. Strangelove
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