Re: anonymous records as tuples

[Stephen Leake <stephen_leake@stephe-leake.org>]

On Monday, March 12, 2018 at 2:17:08 PM UTC-5, Robert Eachus wrote:
> On Monday, March 12, 2018 at 1:32:46 PM UTC-4, Stephen Leake wrote:
> > I recently had to change a function that returned a single integer into a procedure that returns two...
> 
> What is wrong with something like:
> 
> -- in Tree:
> 
> type Return_Values is record
>    Real : Integer; 
>    Virtual : Integer;
> end record;
> 
> function Count_Terminals (Index...) return Return_Values;
> ...
> 
> declare 
>   Returned: constant Tree.Return_Values := Tree.Count_Terminals(Index);
>   Real: Integer renames Returned.Real;
>   Virtual: Integer renames Returned.Virtual;
> begin 
>   if Virtual = 0 then 
>      Next_Shared_Token := Next_Shared_Token - Real; 
>   end if;
> end;

That works, but is more verbose; I have to make up a name for the result type, when it's really an anonymous tuple of values. But I suspect the ARG would say the gain is not worth the cost.

> (And declaring Real as an Integer really rubs me wrong.)

This is for a parser; it's counting "real tokens" from the source text versus "virtual tokens" inserted by an error recovery process.

I ended up resolving it a different way; first I check if there are any virtual tokens, then I count real tokens.

-- Stephe