Hi Bram, you might be interested in the “regex” package from my colleague Chris Dornan: http://regex.uk/ I know some proper performance work still needs to be done, but I would be curious to hear your experience report ;) Alfredo On 19 May 2017 at 18:52, Bram Neijt wrote:

Thank you!

I already changed to Text instead, but I thought the regex was already memoized by GHC, so that should not be a problem.

I'm trying regex-applicative now, maybe that will help, but it takes some time to figure out the syntax. I'll also try to see if precompilation helps.

Greetings,

Bram

On Fri, May 19, 2017 at 1:17 PM, Станислав Черничкин wrote:

...

Try to use Text or ByteString instead of strings. Try to use compile and execute methods (http://hackage.haskell.org/package/regex-tdfa-1.2.1/docs/ Text-Regex-TDFA-ByteString.html), make sure regex get compiled once.

2017-05-16 12:12 GMT+03:00 Bram Neijt :

...

Dear reader,

I decided to do a little project which is a simple search and replace program for large text files.

Written in Haskell, it does a few different regex matches on each line and stores them in a leveldb key-value store to create a consistent/reviewable search-replace index. It should provide for some simple/brute-force anonymization of data and therefore I called it hanon (sorry, could not think of a better name).

https://github.com/BigDataRepublic/hanon

The code works, but I've done some benchmarking to compare it with Python and the code is about 80x slower then doing the same thing in Python, making it useless for larger data files.

I'm obviously doing something wrong.

Could you give me tips on improving the performance of this code? Probably mainly looking at

https://github.com/BigDataRepublic/hanon/blob/master/src/Mapper.hs

where the regex code lives?

Greetings,

Bram _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

-- Sincerely, Stanislav Chernichkin.

---

Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

I recommend benchmarking with criterion and GHC profiling so you know where the slow actually is before trying to optimize anything. On Tue, May 23, 2017 at 9:26 AM David Fox wrote:

I have been surprised at how rarely switching to Text or ByteString makes things significantly faster. If you do this you should look at Data.ByteString.Builder or Data.Text.Lazy.Builder.

On Fri, May 19, 2017 at 4:17 AM, Станислав Черничкин < schernichkin@gmail.com> wrote:

...

Try to use Text or ByteString instead of strings. Try to use compile and execute methods ( http://hackage.haskell.org/package/regex-tdfa-1.2.1/docs/Text-Regex-TDFA-Byt...), make sure regex get compiled once.

2017-05-16 12:12 GMT+03:00 Bram Neijt :

...

Dear reader,

I decided to do a little project which is a simple search and replace program for large text files.

Written in Haskell, it does a few different regex matches on each line and stores them in a leveldb key-value store to create a consistent/reviewable search-replace index. It should provide for some simple/brute-force anonymization of data and therefore I called it hanon (sorry, could not think of a better name).

https://github.com/BigDataRepublic/hanon

The code works, but I've done some benchmarking to compare it with Python and the code is about 80x slower then doing the same thing in Python, making it useless for larger data files.

I'm obviously doing something wrong.

Could you give me tips on improving the performance of this code? Probably mainly looking at

https://github.com/BigDataRepublic/hanon/blob/master/src/Mapper.hs

where the regex code lives?

Greetings,

Bram _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

-- Sincerely, Stanislav Chernichkin.

_______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

_______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.