November 2010 - Haskell-Cafe

looking for tagsoup-parsec examples
by José Romildo Malaquias 22 Nov '10

22 Nov '10

Hello. I am looking for some examples of code using Text.HTML.TagSoup.Parsec, from the tagsoup-parsec package. Romildo

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GUI Designer
by c8h10n4o2 22 Nov '10

22 Nov '10

There's a tutorial on how to use qtDesigner with qtHaskell ? Or how to use XRC files with wxHaskell? -- View this message in context: http://haskell.1045720.n5.nabble.com/GUI-Designer-tp3271441p3271441.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.

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Berlin Haskell Meeting
by Sönke Hahn 22 Nov '10

22 Nov '10

The next haskell meeting in Berlin will be this wednesday: Date: Wednesday, November 24th Time: from 20:00 Location: c-base, Rungestrasse 20, 10179 Berlin Hope to see you there, Sönke

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Yesod.Form: Password fields?
by Ertugrul Soeylemez 22 Nov '10

22 Nov '10

Hello everybody, how can I create a password field using Yesod.Form? It doesn't seem to support them. Greets, Ertugrul -- nightmare = unsafePerformIO (getWrongWife >>= sex) http://ertes.de/

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Same compiled program behaving differently when called from ghci and shell
by Bruno Damour 21 Nov '10

21 Nov '10

Hello, I have a very strange (for me) problem that I manage to reduce to this : I have a small program that reads a file with 1 only character (è = e8) The program is ftest2.hs : import IO import Data.Maybe tfind s = lookup (head s) $ zip ['\xe8', '\xde'] "12" main = do h<- readFile "g:\\CODE\\rlib\\test.txt" putStrLn h print $ tfind h I compile it from command line : ghc --make ftest2.hs Now the weird results : 1/ cmd line: ftest2.exe è Just '2' 2/ ghci Prelude> :!ftest2.exe è Just '2' 3/WinGHci Prelude> :! ftest2.exe è Just '1' I tested different variants, there is always a difference. Any idea to help me trace this behaviour ?

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OT: Mailing list for testing email
by Alexander Solla 21 Nov '10

21 Nov '10

Hi everybody This is kind of off topic, but mailing list related. I've been messing around with my email server, to help fix some issues with the new version of Postfix (with regards to my old configuration). I seem to be receiving email intermittently. Does anybody know of a mailing list for email testing? I mean, I would like to be able to "spam" the mailing list with test messages and receive other people's test messages, until I'm sure my configuration is working right, without bothering the Cafe (or any other topic specific list). I know there used to be usenet groups for this purpose, but that's usenet, not email. I guess it would be nice if somebody sent me a quick pong in response to my ping, but I don't want to make too much noise here. Thanks

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Catching up on Time and Directory
by Jon Fairbairn 21 Nov '10

21 Nov '10

I'm probably terribly out of date with this, so I wonder if anyone can save me the bother of working out what the /preferred/ libraries are for (a) determining the last-modified-time of a file or directory and (b) manipulating the resulting time datum. I can find System.Directory.getModificationTime and Data.Time.formatTime, but using them together seems unduly awkward. -- Jón Fairbairn Jon.Fairbairn(a)cl.cam.ac.uk http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated 2010-09-14)

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Codec.Crypto.RSA question
by Charles-Pierre Astolfi 21 Nov '10

21 Nov '10

Hi -cafe, I have a question about Codec.Crypto.RSA: how to enforce that (informally) decrypt . encrypt = id Consider this code: encrypt2 :: String -> ByteString encrypt2 = fst . encrypt (mkStdGen n) pubKey encode decrypt2 :: ByteString -> String decrypt2 = toString . decrypt privKey Since decrypt2 takes a bytestring which size is a multiple of the modulus, I've guessed that the encrypted bytestring is padded with '\NUL' characters. But then some strange stuff shows up: decrypt2 $ encrypt2 "haskell" returns "\NUL\NUL\NUL\NUL\EOThaskell" decrypt2 $ encrypt2 "foobar" returns "\NUL\NUL\NUL\NUL\65533foobar" I may use dropWhile to get rid of the NUL-padding, but can I assume that I'll always get a random character between my string and the padding? I tried to pad myself with NUL characters but I got almost the same results (the "random char" went to the head of the string) -- Cp

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Making HList's field access operators (#) and (.!.) left-associative?
by Josh Triplett 21 Nov '10

21 Nov '10

Hello, In experimenting with HList's very impressive extensible records, I discovered that the field access operators (#) and (.!.) have right associativity; this means I can't write (r # f1 # f2) to access field f2 of the record stored in field f1 of r. If (#) and (.!) had left-associativity instead, then I could write such nested record operations. As far as I can tell, the right-associative binding would only make sense if attempting to store field labels inside a record, which seems much more unlikely. I wrote to the author of HList about this issue, and he agreed that this sounded reasonable, but he wanted me to confirm via haskell-cafe that nobody had code which relied on the existing behavior. Comments? Objections? Thanks, Josh Triplett

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Tooltips on tree view rows
by José Romildo Malaquias 21 Nov '10

21 Nov '10

Hello. I need the gtk_tree_view_set_tooltip_column from Gtk+, but it seems tht it has not been ported to gtk2hs. Is it the case? How can I easily add tooltips to rows in a TreeView? Regards, Romildo

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