[ I am copying my reply to the libraries mailing list ] Georgios Siganos wrote:
Hi Chris, I am checking your library and i have found some problems with the head version on my system (macosx intel with ghc 6.5)
First, I get a compile error when I build regex-tre Wrap.hsc:120:23: error: tre/regex.h: No such file or directory I can build the remaining modules with no errors.
The current README file suggest that you "edit list of BACKENDS in Makefile if you want to exclude regex-tre or regex-pcre" Since you do not have libtre, you can remove it from the BACKENDS near the top of the main Makefile. Theoretically, if you edited regex-tre/regex-tre.cabal to not define -DHAVE_TRE_H then regex-tre would compile and install, but using it would be an error. This is not going to work at the moment since I have not recently tested that part of the source. But it could be handy if you want the module to exist, but not depend on compiling against libtre.
Second, I can successfully run your examples, but when i run TestTextRegexLazy I get a segmentation fault ... "StringPCRE" Us (backrefs): Cases: 15 Tried: 15 Errors: 0 Failures: 0 Us (lazy patterns): Cases: 31 Tried: 31 Errors: 0 Failures: 0 Us (possessive patterns): Cases: 27 Tried: 27 Errors: 0 Failures: 0 Us (shared): Cases: 344 Tried: 50 Errors: 0 Failures: 0Segmentation fault I am not sure how helpful this can be, let me know if you want more details to find the cause of the segmentation fault. Note, that the stable version passes all the tests.
Hmmm....I just uploaded (about 10 minutes before your e-mail) version 0.70 to both http://evenmere.org/~chrisk/trl/head/ and http://evenmere.org/~chrisk/trl/stable. There was a pcre segfault that was fixed back in version 0.66 or 0.67. (The FunPtr to pcre_free was null, so it died randomly whenever the garbage collector ran.)
Regarding the documentation, is there an easy way to produce it, or are you still working on it?
./setup haddock in each of the regex-* subdirectories will build ./dist/doc/* but I don't have an automatic documentation installer.
Finally, do you have any suggestion on how I can use sth similar to splitRegex on a ByteString? I want to split a ByteString using "\n\n" as a delimiter, and i am not sure what is the best way to do it.
I will eventually expand the compatibility API to provide that. If you needed the split to be lazy, you can copy what regex-compat/Text/Regex/New.hs does:
splitRegex :: Regex -> String -> [String] splitRegex _ [] = [] splitRegex delim str = case matchM delim str of Nothing -> [str] Just (firstline, _, remainder, _) -> if remainder == "" then firstline : [] : [] else firstline : splitRegex delim remainder
But a more efficient way would be to get all the matches from PCRE in one pass and then return all the intermediate parts:
import Data.ByteString.Char8 import Text.Regex.Base import Text.Regex.PCRE
split' :: Regex -> ByteString -> [ByteString] split' regex source = let matches :: [(MatchOffset,MatchLength)] matches = match regex source process pos _ | pos `seq` False = undefined process pos [] = [after pos source] process pos ((s,o):rest) = extract (pos,s-pos) source : process (s+o) rest in process 0 matches
*Main> split' (makeRegex "l|d") (pack "Hello World") ["He","","o Wor","",""] *Main> split' (makeRegex "l|o.") (pack "Hello World") ["He","","","W","","d"] *Main> split' (makeRegex ".o|\?") (pack "Hello World, how are you?") <interactive>:1:24: lexical error in string/character literal *Main> split' (makeRegex ".o") (pack "Hello World, how are you?") ["Hel"," ","rld, ","w are ","u?"] *Main> split' (makeRegex "l|.o") (pack "Hello World, how are you?") ["He","","o ","r","d, ","w are ","u?"] *Main> split' (makeRegex "H") (pack "Hello World, how are you?") ["","ello World, how are you?"] *Main> split' (makeRegex "H|h") (pack "Hello World, how are you?") ["","ello World, ","ow are you?"] *Main> split' (makeRegex "\n\n") (pack "Hello \nWorld,\n\n how\n are you?") ["Hello \nWorld,"," how\n are you?"]
Keep on the good work, Georgos
:)