Re: Case statement and Integers.

[Alan Reynolds <alan1@bellatlantic.net>]

Hi Chris,

It would seem that you need to review the RM (or course notes) 
concerning the use of the "case" statement and what constitutes a valid 
alternative ("when <discrete_choice_list> =>").  What's appropriate here 
is to use an "if ... then ... elsif ... then ... else ... end if" statement.

If "left_swap" and "right_swap" are indices similar to "j" then you 
simply provide "numbers(left_swap)" and "numbers(right_swap)" as 
arguments to "swap".

This brings back fond memories of my 2nd quarter comp. sci. class 
assignment to implement the "quicksort" algorithm in Pascal.  Keep 
working on it.

Have fun,
Al

Wannabe h4x0r wrote:
> I have a statement like this...
> 
> 	case numbers(j) is
> 		when numbers(j) < pivot => swap(left_swap, right_swap); 
> 		-- If the number is less than the pivot, swap it with the number
> 		-- to the right of the Pivot;
> 		when numbers(j) > pivot => swap(right_swap, left_swap);
> 		-- If the number is greater than the pivot, then do the opposite of the
> 		-- above.
> 		when numbers(j) = pivot => null;
> 		when others => null;
> 	end case;
> 
> Now, it's pretty obvious whats wrong here. The swap procedure is
> expecting an Integer, and instead it's getting a boolean value due to the
> '>', '<', and '=>' operators.
> 
> Whats the proper way to indicate to the compiler that I want to send
> the numbers indexed by "left_swap" and "right_swap" to the swap procedure
> rather than the results of the boolean test in the case statement?
> 
> Thanks for your patience.
> 
> Chris