Design of intuitive interfaces

[KennyTM~]

On Feb 22, 10 06:07, Ary Borenszweig wrote:
> Michel Fortin wrote:
>> On 2010-02-21 10:19:06 -0500, bearophile <bearophileHUGS at lycos.com> said:
>>
>>> Michel Fortin:
>>>> array.sort(predicate) // sort in place using predicate
>>>> array.sorted(predicate) // create sorted copy using predicate
>>>> array.isSorted(predicate) // tell if the array is sorted using
>>>> predicate
>>>
>>> Good.
>>>
>>> Another possibility is to let D2 accept ? and ! too inside variable
>>> names, so they can become (as in Ruby I think, and something similar
>>> is common in Lisp-like languages too):
>>> array.sort(predicate)
>>> array.sort!(predicate); // void function
>>> array.sorted?(predicate)
>>
>> Note that Ruby only accept this as a suffix, but yeah it's part of the
>> identifier.
>>
>> And I'd love this, but the ! suffix is totally ambiguous with the
>> template instantiation syntax, and the ? suffix would be ambiguous in
>> the ternary operator "?:".
>
> But ruby has the ternary operator "?:", it just gives the "?" in the
> identifier more precedence.
>
> So there's just the backwards compatibility problem, but if you had:
>
> foo? something : something_else
>
> then now it won't compile ("foo?" can't be found) and you'll have to
> change it to
>
> foo ? something : something_else
>
> so it's a safe backwards incompatible change.

enum foo = false;
enum bar = 2;
...
   case foo?(1):bar: break;

Suddenly, if "foo?" is defined, the value of the case completely changed 
and you've got a "bar" label.