Re: Array Help?

[BrianG <me@null.email>]

On 03/09/2012 03:48 AM, stefan-lucks@see-the.signature wrote:
> On Thu, 8 Mar 2012, Randy Brukardt wrote:
> [...]
>> <stefan-lucks@see-the.signature>  wrote:
>
>>> 1. Testing
>>>
>>> When you declare
>>>
>>>   procedure Sort(Items: in out array(Positive range<>) of T)
>>
>> Let's hope you never do that, because anonymous types are the bane of Ada.
>> And you surely can't do it today!
>
> OK, the real thing would look about like that:
>
>    generic
>       type Element_Type is (<>);
>       type Index_Type is (Positive range<>);
>       type Collection_Type is array(Index_Type range<>) of Element_Type;
>       with function "<"(Left, Right : Element_Type) return Boolean is<>;
>
>    function Sort(Items : Collection_Type) return Collection_Type;
>
>>> in a package specification, and you try to write a proper black-box test,
>>> you need *more* test cases then when you do the same with another popular
>>> language.
>>
>> Right. Bob's suggestion for some semi-constrained array subtype would fix
>> that. But note that it was killed in Ada 95 in part because the
>> implementation needed was essentially a record type with some sort of magic
>> indexing. Which was a mess.
>
> Would it ease the implementation if you constrain the start index to some
> fixed value, such as Index_Type'First?

If that's what you want, why can't you (in this case) define that in 
your generic parameters, rather than an index range (which already has a 
defined type)?

-- 
---
BrianG
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