• Andrej Mitrovic <none none.none> Mar 21 2011
• Andrej Mitrovic <andrej.mitrovich gmail.com> Mar 21 2011
• bearophile <bearophileHUGS lycos.com> Mar 21 2011
• Jonathan M Davis <jmdavisProg gmx.com> Mar 21 2011
• bearophile <bearophileHUGS lycos.com> Mar 21 2011
• Andrej Mitrovic <andrej.mitrovich gmail.com> Mar 21 2011

Andrej Mitrovic <none none.none> writes:

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?

Andrej Mitrovic <andrej.mitrovich gmail.com> writes:

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;
}

bearophile <bearophileHUGS lycos.com> writes:

Andrej Mitrovic:

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


Do you know why?

Bye,
bearophile

Jonathan M Davis <jmdavisProg gmx.com> writes:

 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

bearophile <bearophileHUGS lycos.com> writes:

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

Andrej Mitrovic <andrej.mitrovich gmail.com> writes:

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?