indexing tuples using strings

[Bill Baxter]

On Tue, Dec 2, 2008 at 7:26 PM, bearophile <bearophileHUGS at lycos.com> wrote:
> Bill Baxter:
>
>>What about Perl shows that auto-flattening is bad?<
>
>
> You can find a note here:
> http://steve.yegge.googlepages.com/ancient-languages-perl
>>
> Larry decided to flatten lists by default. Hence, if you write this:
> @x = (1, 2, 3, (4, 5));
> It automagically turns into (1, 2, 3, 4, 5).
> <

Wow, I guess it really has been a long time for me and Perl.  Don't
recall that little quirk at all.

> The ability of creating trees with arbitrary nested tuples/arrays is really handy (I don't know if the variant type of Tango allows to do this. The boxed of Phobos doesn't allow it, I think).
>
>>Isn't there an easier way to fake it using structs?<
>
> In my dlibs I've added a Record/record that can be used a little as a Python tuple, the Record can be found here:
> http://www.fantascienza.net/leonardo/so/dlibs/templates.html

Hmm, but just to play devils advocate here, you've implemented it, BCS
implemented, and I implemented it again this morning.  That would seem
to argue that the current state is fine, the unflattenable tuple type
just needs to be in the standard lib(s) so people don't have to keep
rolling their own.

(Personally I agree non-flattening would be better and argued for it
soon after Tuples came out, but somehow I doubt Walter's going to be
convinced to break a significant amount of Tuple-using template code
without a more ... convincing argument.  Something like a
demonstration of some of BCS's compile-time parser written with and
without auto-flattening tuples showing a dramatic reduction in code
for the no-flattening case.)

--bb