Re: [Gm2] Re: GM2 ISO

[Iztok]

Gaius Mulley wrote:

> Iztok <address@hidden> writes:
>
>  
>
> > Gaius Mulley wrote:
> >
> > As implemented, LENGTH takes only constant parameter while it should
> > take variable ones also. I've checked with my GP M2, SB M2 and XDS M2
> > manuals as well as with the few sites that have ISO M2 doc. It seems
> > that while some have had doubts about LENGTH being pervasive at
> > beginning, they all have adopted it and made it take variable
> > parameter as well.
> >    
>
> thanks for reporting this. I had thought that LENGTH only should work
> with constants, but it is easy to alter this. It raises a couple of
> questions:
>
>   (i)   does LENGTH(a) behave like HIGH(a)+1 for an open array
>         or                         strlen(a)
>  
LENGTH = Strings.Length = strlen

I think that this was the point of LENGTH discussions - LENGTH has its 
function only when pervasive. If imported, there was no difference 
between LENGTH and Strings.Length. And the reason for implementing 
LENGTH is only for not importing Strings module at all. Which, again, is 
more important for compilers which can not optimize for unaccessed code 
at link time. Which, I hope (and unfortunately do not know) gcc and gm2 do.

>   (ii)  within constant expressions, presumably LENGTH is limited to
>         a constant parameter.
>  
I think that the compiler has enough information to use the constant 
string length constant at the compile time, and it should. Which again 
can not be the case with the Strings.Length where the constant string 
could only be evaluated at run time. And might be that it was another 
reason for LENGTH implementing.

I.