automatic int to short conversion - the HELL?

[Jarrett Billingsley]

On Fri, Sep 19, 2008 at 9:29 AM, Ary Borenszweig <ary at esperanto.org.ar> wrote:
> bearophile wrote:
>>
>> Ary Borenszweig:
>>>
>>> No, no. In Java it's an error, an explicit cast is required.
>>> http://www.programmersheaven.com/2/FAQ-JAVA-Type-Conversion-Casting
>>> Which is perfect. It expresses the intents of the programmer:
>>
>> About such matters I suggest you all to also take a look at how Ada works.
>> Ada was designed first of all to create reliable software, so avoiding
>> casting-derived bugs too is essential.
>> D tries to avoid some of the pitfalls of C, to be a language less
>> bug-prone: casts is where D has to improve still in such regards. Time ago
>> (when I was more a D newbie) I have already had a bug in my code because of
>> a casting bug:
>>
>> import std.stdio;
>> void main() {
>>    int n = -5;
>>    int[] a = [1, 2, 3];
>>    writefln(a.length > n); // prints false
>> }
>>
>> A well designed language, even a system language like Ada or D, must avoid
>> such kinds of bugs, regardless the amount of ignorance of the programmer.
>
> Wow. At first, I thought that was already fixed. Now I've written that code,
> compiled it and run it and saw it gives false. Ok, I know a.length is an
> uint because logically it cannot be negative. But... shouldn't it be an int
> to avoid this kind of bugs?? You loose nothing doing this. You are never
> going to need an array of 2147483647 positions, much less a bigger array.
>
> I've checked C#, which has uint as a type. The length of an array is an int,
> not an unit. A much better choice.

signed-unsigned comparison is, I think, a slightly larger problem than
the type of array.length ;)