OpenEuphoria

Re: Wishlist

• Posted by Irv Mullins <irvm at ellijay.com> Jun 28, 2001
• 561 views

On Thursday 28 June 2001 01:34, Tony Bucholtz wrote:

> I don't think anyone wants to change the value of the loop variable
> *inside* the loop. The suggestion is for another way to set the
> value of the loop variable *prior* to its use inside the loop.
> Ferinstance, if I wanted to process only certain elements of a
> sequence, I'd have to use something like:
>
> sequence seqindex
> seqindex = {3, 5, 10, 21, 22, 40, 45, 50, 63}
> for i = 1 to length(seqindex)
>   seq2process[seqindex[i]] = <something>
> end for
>
> The suggestion is for an easier way to do this sort of work, eg:
>
> foreach i = {3, 5, 10, 21, 22, 40, 45, 50 ,63}
>   seq2process[i] = <something>
>   ? i
> end foreach

OK, now I understand what you're asking. And, as it turns out, I use 
that kind of thing sometimes, for example, printing notices to past 
due accounts, extracted from a list of accounts. Here's a simple demo:

procedure PrintMe(object x)
 ? x -- do anything you want here
end procedure
 
procedure foreach(sequence list, atom rtn)
  for i = 1 to length(list) do
     call_proc(rtn,{list[i]})
  end for
 end procedure
 
foreach({1,4,7,8},routine_id("PrintMe"))

Problems with this include the necessity of writing both a foreach 
procedure and a foreach function, they are not interchangeable.

And, if foreach() is made part of a library, the "include foreach.e" 
has to appear AFTER the PrintMe() routine, so that it can"see" 
the user-written PrintMe() routine.

A built-in foreach() would be nice.

Regards,
Irv