Re: [Haskell-cafe] Filesystem questions

2007-10-19 Thread Bulat Ziganshin
Hello Andrew, Friday, October 12, 2007, 9:21:07 PM, you wrote: > I notice that getDirectoryContents appears to return its results in > alphabetical order. Is this behaviour actually guaranteed? on NTFS filesystem, files are stored in directory alphabetically sorted. on FAT disks the order may b

Re: [Haskell-cafe] Filesystem questions

2007-10-14 Thread Henning Thielemann
On Sun, 14 Oct 2007, Bryan O'Sullivan wrote: Yitzchak Gale wrote: I do think that it is much better to provide IO laziness using monad transformers (or whatever) rather than unsafe IO. That's fair enough. I think it would be great if you were to turn your ideas into a library and provide

Re: [Haskell-cafe] Filesystem questions

2007-10-14 Thread Bryan O'Sullivan
Yitzchak Gale wrote: I do think that it is much better to provide IO laziness using monad transformers (or whatever) rather than unsafe IO. That's fair enough. I think it would be great if you were to turn your ideas into a library and provide a few examples of its use. http://www.

Re: [Haskell-cafe] Filesystem questions

2007-10-14 Thread Yitzchak Gale
Hi Bryan, You wrote: > This is little different from the approach taken by Python's os.walk, > which lazily yields the contents of a directory tree as it traverses it. > I'm a little unclear on why one appears good in your eyes, while the > other is not, beyond perhaps the depth/breadth knob and

Re: [Haskell-cafe] Filesystem questions

2007-10-14 Thread Bryan O'Sullivan
Yitzchak Gale wrote: Your library is very nice. But - it suffers from the same problem. You use unsafe IO operations to build a "lazy" IO list, and we all know what grief that can lead to. This is little different from the approach taken by Python's os.walk, which lazily yields the contents o

Re: [Haskell-cafe] Filesystem questions

2007-10-14 Thread Ian Lynagh
Hi Yitzchak, On Sun, Oct 14, 2007 at 11:33:38AM +0200, Yitzchak Gale wrote: > > Here it is critical that ListT be taken from > > http://haskell.org/haskellwiki/ListT_done_right > > and not the broken implementation that comes with mtl. > (Finally fixed in 6.8? Please?) mtl is not part of GHC

Re: [Haskell-cafe] Filesystem questions

2007-10-14 Thread Yitzchak Gale
I wrote: >>> ...a tool for recursing through directories... >>> How about a built-in function that represents a directory tree >>> as a lazy Data.Tree? Bryan O'Sullivan wrote: >> See System.FilePath.Find in >> http://hackage.haskell.org/cgi-bin/hackage-scripts/package/FileManip-0.2 > -- List all

Re: [Haskell-cafe] Filesystem questions

2007-10-14 Thread Yitzchak Gale
I wrote: >> How about a built-in function that represents a directory tree >> as a lazy Data.Tree? Jules Bean wrote: > Please no. > The last thing haskell needs is more dangerous semantically broken > non-referentially-transparent lazy IO structures. Agreed. I would definitely not want it to be a

Re: [Haskell-cafe] Filesystem questions

2007-10-14 Thread Yitzchak Gale
I wrote: >> ...a tool for recursing through directories... >> How about a built-in function that represents a directory tree >> as a lazy Data.Tree? Bryan O'Sullivan wrote: > See System.FilePath.Find in > http://hackage.haskell.org/cgi-bin/hackage-scripts/package/FileManip-0.2 > Not a very good i

Re: [Haskell-cafe] Filesystem questions

2007-10-14 Thread Andrew Coppin
Jules Bean wrote: Yitzchak Gale wrote: How about a built-in function that represents a directory tree as a lazy Data.Tree? Please no. The last thing haskell needs is more dangerous semantically broken non-referentially-transparent lazy IO structures. Woah! Well, I understood *one* of thos

Re: [Haskell-cafe] Filesystem questions

2007-10-14 Thread Jules Bean
Yitzchak Gale wrote: How about a built-in function that represents a directory tree as a lazy Data.Tree? Please no. The last thing haskell needs is more dangerous semantically broken non-referentially-transparent lazy IO structures. Jules ___ Hask

Re: [Haskell-cafe] Filesystem questions

2007-10-13 Thread Bryan O'Sullivan
Yitzchak Gale wrote: Python also has os.walk, a very convenient functional (sort of) tool for recursing through directories. (It sounds trivial, but it is not, there are enough annoying details that this function saves huge amounts of time.) Very embarrassing that Haskell is missing this. See

Re: [Haskell-cafe] Filesystem questions

2007-10-13 Thread Magnus Therning
On Sat, Oct 13, 2007 at 23:27:13 +0200, Yitzchak Gale wrote: >Andrew Coppin wrote: >>> Is there a way to get rid of "." and ".." in the results? > >Brandon S. Allbery wrote: >> Manual filtering is always required, whether C, Perl, Haskell, etc. >> I dunno, maybe python filters them for you or somet

Re: [Haskell-cafe] Filesystem questions

2007-10-13 Thread Henning Thielemann
On Sat, 13 Oct 2007, Yitzchak Gale wrote: Andrew Coppin wrote: Is there a way to get rid of "." and ".." in the results? Brandon S. Allbery wrote: Manual filtering is always required, whether C, Perl, Haskell, etc. I dunno, maybe python filters them for you or something. Correct, Python f

Re: [Haskell-cafe] Filesystem questions

2007-10-13 Thread Yitzchak Gale
Andrew Coppin wrote: >> Is there a way to get rid of "." and ".." in the results? Brandon S. Allbery wrote: > Manual filtering is always required, whether C, Perl, Haskell, etc. > I dunno, maybe python filters them for you or something. Correct, Python filters them out. This is clearly the correc

Re: [Haskell-cafe] Filesystem questions

2007-10-12 Thread Steve Schafer
On Fri, 12 Oct 2007 18:21:07 +0100, you wrote: >I notice that getDirectoryContents appears to return its results in >alphabetical order. Is this behaviour actually guaranteed? This is a Windows thing. All of the NT-based operating systems list files in alphabetical order by default. You see the

Re: [Haskell-cafe] Filesystem questions

2007-10-12 Thread Brandon S. Allbery KF8NH
All these questions are actually Windows-centric; the answers are different on Unix. On Oct 12, 2007, at 13:21 , Andrew Coppin wrote: I notice that getDirectoryContents appears to return its results in alphabetical order. Is this behaviour actually guaranteed? There is no guarantee, howeve

[Haskell-cafe] Filesystem questions

2007-10-12 Thread Andrew Coppin
I notice that getDirectoryContents appears to return its results in alphabetical order. Is this behaviour actually guaranteed? Related: Is there a way to get rid of "." and ".." in the results? (Obviously this causes directory recusion to malfunction.) I can of course manually filter them out,