[erlang-questions] If you are homesick for object.selector

[Loïc Hoguin]

On 01/28/2013 02:57 AM, Garrett Smith wrote:
> On Sun, Jan 27, 2013 at 7:23 PM, Robert Virding
> <robert.virding@REDACTED> wrote:
>>
>> ----- Original Message -----
>>> From: "Richard O'Keefe" <ok@REDACTED>
>>>
>>> This is _so_ on-topic...
>>>
>>> http://thedailywtf.com/Articles/Ancestors.aspx
>>
>> Think how much more difficult to read it would have been if you had to include the record names. :-)
>
> For the benefit of those who didn't click the link, it contains this
> function in C#:
>
> private void MouseMove(object sender, MouseEventArgs e)
> {
>     (sender as PictureBox).Parent.Parent.Parent.Parent.Parent.GetType();
> }
>
> After seeing that, I'm convinced Erlang record syntax is one the
> language's best features. If other languages had such a tax, this sort
> of thing would be held in check.
>
> Call it a sin tax.

Except that's completely different from what we'd like to have.

  *  We do not want a parent() mechanism.
  *  We do not want pointers or references.
  *  We do not want to be able to call functions.

Also note that with regards to Erlang, it's *not* syntax that prevents 
this kind of behavior, but processes and message passing. Your process 
can only handle so much.

We just need a data structure and associated syntax that's convenient 
for semi-deep data structures, where the fields are clearly defined 
(like a record), except field resolution would be performed at runtime 
to allow chaining and thus easier pattern match and/or modification. And 
ironically it could also easily solve the record upgrade problem, 
because you'd have the fields at runtime.

Data manipulation is something that can make or break projects, and is 
the reason why I stopped one of mine, because all the solutions you can 
think of are light years away of what can be achieved with very little 
language support.

Of course, language support means first acknowledging there is indeed a 
problem, and I am not surprised to hit walls here, especially in the 
"you just need functions" crowd (who don't seem to be aware of how nice 
pattern matching in function clauses and guards are). So I'll experiment 
on my end for a while and if it turns out that it works I might just use 
this new language for the previously mentioned project. That'd certainly 
motivate me enough to reboot it.

Have a nice day.

-- 
Loïc Hoguin
Erlang Cowboy
Nine Nines
http://ninenines.eu