[phobos] What's the status of listDir/listdir ?

Jonathan M Davis jmdavisProg at gmx.com
Fri Jun 10 09:21:56 PDT 2011


On 2011-06-10 05:22, Dmitry Olshansky wrote:
> On 10.06.2011 16:19, Andrei Alexandrescu wrote:
> > On 6/10/11 4:47 AM, Jonathan M Davis wrote:
> >> The main problem with dirEntries is essentially as you point out. It
> >> doesn't
> >> work with anything but foreach. You can't even pass it to
> >> std.array.array to
> >> create an array. And it's because it's set up to work with either a
> >> string or
> >> a DirEntry for the loop variable. The advantage of listdir/listDir is
> >> that you
> >> get an actual array of strings to use when you need to pass it to
> >> something.
> >> Ideally, DirIterator wolud be made to work with more, but it hasn't
> >> been. I
> >> don't know if we want to try and turn it into a range or what, but it
> >> is a bit
> >> of a problem if you want to use dirEntries outside of a foreach loop.
> > 
> > Any chance of somebody finding the time to transform dirEntries into
> > an input range? That would solve everything.
> 
> I decided to try just that. It will take some time though.

The only thing that I can think of doing is making it so that DirIterator is a 
range with element type DirEntry and make DirEntry have an alias this to its 
name property. I _think_ that that will give the same behavior as the current 
behavior. Certainly, I don't know how else we'd do it. The ability to have 
multiple iteration types for the same range is not exactly one of ranges 
strong points.

Feel free to rearrange DirIterator and _listDir's internals as long as it 
doesn't break the current good behavior (that is, how dirEntries works with 
foreach and how listdir/listDir works, though listdir/listDir can have a 
separate implemnetation if need be, since it's going away). And if you're 
actually going to end up messing with the internals rather than just changing 
DirIterator's API, then keep this bug in mind: 
http://d.puremagic.com/issues/show_bug.cgi?id=6138 (currently, calling chdir 
in the middle of iterating with dirEntries causes problems). I'm not sure 
whether the current behavior is what we want or not, since it's a bit like 
modifying a collection or range while iterating over it, and that's not 
necessarily something that you can expect to work. But if it's an easy fix to 
make it work, then that's what we probably want. If you're just messing with 
DirIterator's API rather than how it works internally though, then don't worry 
about it. We can sort out 6138 later.

- Jonathan M Davis


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