[Haskell-cafe] unexpected behavior from filterM doesFileExist =<< getDirectoryContents

Thomas Hartman tphyahoo at gmail.com
Sun Jan 10 01:33:14 EST 2010


Thanks, that was it.

Dud question.

2010/1/9 Brandon S. Allbery KF8NH <allbery at ece.cmu.edu>:
> On Jan 10, 2010, at 00:24 , Thomas Hartman wrote:
>>
>> Can somebody explain this?
>>
>>> getDirectoryContents inD
>>
>> ["..","#sanity
>> .txt
>> #",".","sanity
>> .txt
>> ","etc
>> .txt
>> ","patchTagDir
>> .txt
>> ","jail
>> .txt","notjail.txt","alldata.txt","allobjs.txt","namesNSizes.txt"]
>>
>>> filterM doesFileExist =<< getDirectoryContents inD
>>
>>> ["sanity.txt"]
>
>
> My first guess is that inD isn't "."; getDirectoryContents doesn't fully
> qualify the names it returns, so doesFileExist looks in the current
> directory for the bare names returned.
>
> --
> brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery at kf8nh.com
> system administrator [openafs,heimdal,too many hats] allbery at ece.cmu.edu
> electrical and computer engineering, carnegie mellon university    KF8NH
>
>
>


More information about the Haskell-Cafe mailing list