Array literals

[Steven Schveighoffer]

"Andrei Alexandrescu" wrote
> Steven Schveighoffer wrote:
>> "Sergey Gromov" <snake.scaly at gmail.com> wrote in message 
>> news:MPG.23615f5e560d4d3f989763 at news.digitalmars.com...
>>> Wed, 15 Oct 2008 21:12:31 -0400,
>>> Steven Schveighoffer wrote:
>>>> "bearophile" <bearophileHUGS at lycos.com> wrote in message
>>>> news:gd63sv$2j0t$1 at digitalmars.com...
>>>>> Steven Schveighoffer:
>>>>>> I think this can be solved even simpler.  Make string literal type be
>>>>>> invariant(char)[] instead of static array.  It does not need to be on 
>>>>>> the
>>>>>> heap.  That would solve lots of IFTI problems too.
>>>>> With your idea this syntax:
>>>>> auto a = ["Hello", "what"];
>>>>> Gives a fixed-sized array of invariant(char)[]. I think that's 
>>>>> asymmetric.
>>>>> My suggestion works with all arrays, so the array 'a' too becomes/is
>>>>> dynamic, keeping the simmetry.
>>>> Sure, make the type dynamic for all array literals.  My issue is with 
>>>> your
>>>> proposal to make the data allocated on the heap.
>>>>
>>>> There is no need for an array literal to be typed as a static array. 
>>>> Ever.
>>> I can see one need, matrix literals:
>>>
>>> auto blah =
>>> [
>>>  [ 1,  0,  0 ],
>>>  [ 0,  0, -1 ],
>>>  [ 0, -1,  0 ]
>>> ];
>>>
>>> so that blah is a sequence of 9 numbers accessed accordingly, not 3
>>> arrays of arbitrary length each.
>>>
>>> Well, it's probably a special case and deserves a special, safer syntax.
>>
>> Just don't use auto:
>>
>> int[3][3] blah = ...
>>
>> Make it clear your intention.  A literal should follow the most common 
>> usage, and leave the corner cases to specific syntax.  Most people don't 
>> use static arrays when working with literals.  The most common usage of 
>> static arrays I've seen is to establish a buffer on the stack:
>>
>> byte[1000] buf = void;
>
> Walter wanted to do things that way. I wanted to implement things the 
> T[auto] way. The problem with specifying size twice is that there are two 
> points of maintenance. If the language can help, why not?
>
> Andrei

Yes, good point.

What about using static, there's a keyword that screams out 'this is static' 
:)

byte[static] = [0,1,2];

or

auto[static] = [0,1,2]; // typed as int[3]

T[auto] could look like you are trying to declare an AA with the key type 
being inferred.  But of course, that's probably very rare.

Just playing around ;)  No idea if people would like that syntax, static is 
already heavily overloaded.

-Steve