[Haskell-cafe] file splitter with enumerator package

[yi huang]

On Tue, Jul 26, 2011 at 12:19 PM, yi huang <yi.codeplayer at gmail.com> wrote:

> Actually, i'm wondering how to do exception handling and resource cleanup
> in iteratee, e.g. your `writer` iteratee, i found it difficult, because
> iteratee is designed to let enumerator manage resources.
>
>
I've found the answer for myself,  `catchError` and `tryIO` is for this.
here is an example code: http://hpaste.org/49530#a49565


>
> On Sat, Jul 23, 2011 at 2:41 AM, Eric Rasmussen <ericrasmussen at gmail.com>wrote:
>
>> Hi everyone,
>>
>> A friend of mine recently asked if I knew of a utility to split a
>> large file (4gb in his case) into arbitrarily-sized files on Windows.
>> Although there are a number of file-splitting utilities, the catch was
>> it couldn't break in the middle of a line. When the standard "why
>> don't you use Linux?" response proved unhelpful, I took this as an
>> opportunity to write my first program using the enumerator package.
>>
>> If anyone has time, I'm really interested in knowing if there's a
>> better way to take the incoming stream and output it directly to a
>> file. The basic steps I'm taking are:
>>
>> 1) Data.Enumerator.Binary.take -- grabs the user-specified number of
>> bytes, then (because it returns a lazy ByteString) I use
>> Data.ByteString.Lazy.hPut to output the chunk
>> 2) Data.Enumerator.Binary.head -- after using take for the big chunk,
>> it inspects and outputs individual characters and stops after it
>> outputs the next newline character
>> 3) I close the handle that steps 1&2 used to output the data and then
>> repeat 1&2 with the next handle (an infinite lazy list of filepaths
>> like part1.csv, part2.csv, and so on)
>>
>> The full code is pasted here: http://hpaste.org/49366, and while I'd
>> like to get any other feedback on how to make it better, I want to
>> note that I'm not planning to release this as a utility so I wouldn't
>> want anyone to spend extra time performing a full code review.
>>
>> Thanks!
>> Eric
>>
>> _______________________________________________
>> Haskell-Cafe mailing list
>> Haskell-Cafe at haskell.org
>> http://www.haskell.org/mailman/listinfo/haskell-cafe
>>
>
>
>
> --
> http://www.yi-programmer.com/blog/
>



-- 
http://www.yi-programmer.com/blog/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/haskell-cafe/attachments/20110727/b2f72f2b/attachment.htm>