I'm running across places in my code where I want to test an array for the existence of a certain value:

    Foo[] array;
    Foo value;
    // need to check: is value in array?
    if(value in array) // this doesn't work, so far
    {
      ..
    }

Right now, I'm wavering.  In one place, I created an associative array of bits, and then I get the "keys" property to get the real values:
    bit[Foo] array;
    Foo value;
    if(value in array) // this works
    {
      ..
    }

In another, I'm thinking of writing an actual search function.

Perhaps a wishlist item, I suppose...

Russell Lewis wrote:
> I'm running across places in my code where I want to test an array for the existence of a certain value:
> 
>     Foo[] array;
>     Foo value;
>     // need to check: is value in array?
>     if(value in array) // this doesn't work, so far
>     {
>       ..
>     }

I agree, this should be valid, even though the implementation will just be a linear search.  Marked in TODO.

I think this is a great and natural idea. Thanks!

"Russell Lewis" <spamhole-2001-07-16@deming-os.org> wrote in message news:3D91E904.2080409@deming-os.org...
> I'm running across places in my code where I want to test an array for the existence of a certain value:
>
>      Foo[] array;
>      Foo value;
>      // need to check: is value in array?
>      if(value in array) // this doesn't work, so far
>      {
>        ..
>      }
>
> Right now, I'm wavering.  In one place, I created an associative array
> of bits, and then I get the "keys" property to get the real values:
>      bit[Foo] array;
>      Foo value;
>      if(value in array) // this works
>      {
>        ..
>      }
>
> In another, I'm thinking of writing an actual search function.
>
> Perhaps a wishlist item, I suppose...
>

> I'm running across places in my code where I want to test an array for the existence of a certain value:
>
>      Foo[] array;
>      Foo value;
>      // need to check: is value in array?
>      if(value in array) // this doesn't work, so far
>      {
>        ..
>      }
>
> Right now, I'm wavering.  In one place, I created an associative array
> of bits, and then I get the "keys" property to get the real values:
>      bit[Foo] array;
>      Foo value;
>      if(value in array) // this works
>      {
>        ..
>      }
>
> In another, I'm thinking of writing an actual search function.
>
> Perhaps a wishlist item, I suppose...

If it were valid, the "in" sintax wouldn't need to be valid for
associative arrays, since you would be able to write "key in assArray.keys;"
This should be optimized by the compiler and can decrease the language
complexity (and maybe the compiler's one), though increasing the typing.
Just thoughts.

Dario wrote:

> > I'm running across places in my code where I want to test an array for the existence of a certain value:
> >
> >      Foo[] array;
> >      Foo value;
> >      // need to check: is value in array?
> >      if(value in array) // this doesn't work, so far
> >      {
> >        ..
> >      }
> >
> > Right now, I'm wavering.  In one place, I created an associative array
> > of bits, and then I get the "keys" property to get the real values:
> >      bit[Foo] array;
> >      Foo value;
> >      if(value in array) // this works
> >      {
> >        ..
> >      }
> >
> > In another, I'm thinking of writing an actual search function.
> >
> > Perhaps a wishlist item, I suppose...
>
> If it were valid, the "in" sintax wouldn't need to be valid for
> associative arrays, since you would be able to write "key in assArray.keys;"
> This should be optimized by the compiler and can decrease the language
> complexity (and maybe the compiler's one), though increasing the typing.
> Just thoughts.

This actually might be a very good idea, since a programmer might want to know if a value is "in keys" or "in values".  I would support doing this.  Disallow the "in" property for associative arrays, but make an explicit suggestion that the compiler optimize for "value in assocArray.keys" and "value in assocArray.values".

--
The Villagers are Online! http://villagersonline.com

.[ (the fox.(quick,brown)) jumped.over(the dog.lazy) ]
.[ (a version.of(English).(precise.more)) is(possible) ]
?[ you want.to(help(develop(it))) ]