Currently we have DirEntries, which can be used in a foreach loop. We also have listDir, which returns a string[] with all entries found in a path. listDir is scheduled for deprecation, so I'm not using it.

DirEntries is definitely more flexible, but I can't eagerly construct an array of strings from it. For example, this won't compile:

string[] entries = array(dirEntries(directory, SpanMode.shallow));

Instead I have to expand the code to this:
string[] entries;
foreach (string name; dirEntries(directory, SpanMode.shallow))
{
    entries ~= name;
}

That's just a waste of precious space. Would it be a good idea to make a feature request for this?

Well anywho I've wrapped it in my code:

string[] arrayDirEntries(string path, SpanMode spanMode)
{
    string[] result;
    foreach (string name; dirEntries(path, spanMode))
    {
        result ~= name;
    }
    return result;
}

Andrej Mitrovic:

> this won't compile:
> 
> string[] entries = array(dirEntries(directory, SpanMode.shallow));

Do you know why?

Bye,
bearophile

> Andrej Mitrovic:
> > this won't compile:
> > 
> > string[] entries = array(dirEntries(directory, SpanMode.shallow));
> 
> Do you know why?

Yes. With dirEntries, you have to tell it the iteration type. It could be either a DirEntry or a string. As such, it fails the template constraint for array. It would probably be possible to extend array to work with it (with you giving it the iteration type as a template argument), but array would have to be reworked a bit for that to work.

- Jonathan M Davis

On 3/22/11, bearophile <bearophileHUGS@lycos.com> wrote:
> Andrej Mitrovic:
>
>> this won't compile:
>>
>> string[] entries = array(dirEntries(directory, SpanMode.shallow));
>
> Do you know why?
>
> Bye,
> bearophile
>

build.d(164): Error: template std.array.array(Range) if
(isIterable!(Range) && !isNarrowString!(Range)) does not match any
function template declaration
build.d(164): Error: template std.array.array(Range) if
(isIterable!(Range) && !isNarrowString!(Range)) cannot deduce template
function from argument types !()(DirIterator)

I'm not sure why array() has this signature. Perhaps it needs an update and let any iterable range through?

Jonathan M Davis:

> Yes. With dirEntries, you have to tell it the iteration type. It could be either a DirEntry or a string. As such, it fails the template constraint for array. It would probably be possible to extend array to work with it (with you giving it the iteration type as a template argument), but array would have to be reworked a bit for that to work.

Thank you for your answer and I see, you may mean to optionally give it the item type:

string[] entries = array!string(dirEntries(directory, SpanMode.shallow));

Bye,
bearophile