[Haskell-cafe] Understanding Iteratees
Hello, I am trying to wrap my head around the concept of Iteratee reading the article by John Lato in Monad Reader issue 16 (http://themonadreader.files.wordpress.com/2010/05/issue16.pdf). I followed the "advice" on page 34: "I have frequently heard reports from Haskellers (including highly-talented and experienced users) that the only way they could understand enumeration-based I/O was by re-implementing it themselves." and so reimplemented this code in Java which is, for better and worse, my current professional language (and there really is no point in writing my own 50th iteratee code...). I have a question about iteratees composition and their behaviour. I tried to use the throbber code to display progress while writing a file, without using enumeratees which are introduced later on in the article, but failed. I can bind the two iteratees together, but the writer iteratee consumes the stream of characters to write before handing over the control to the throbber iteratee which has nothing to count. Did I miss something ? Thanks in advance, Arnaud ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Pretty-printer for Text
Hi Ivan You're free to do what you want in your own package, but... Having a Pretty class plus primitive printers int, bool is an advantage. For ints, bools, ... code tends to look neater if you use int or bool rather than pretty. Plus for ints and others you tend to need things like hex printers anyway, so one size via a type class doesn't fit all. As for the class - if I have a reasonably sized syntax tree I'd rather just do > pretty a ... than formulate a naming scheme like: > prettyExpr a Regards Stephen ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] In what language...?
On 27 October 2010 00:21, Richard O'Keefe wrote: > Here's the table of contents of a typical 1st year discrete mathematics book, > selected and edited: > - algorithms on integers > - sets > - functions > - relations > - sequences > - propositional logic > - predicate calculus > - proof > ... Quite a bit of this is covered by "Discrete Mathematics Using a Computer" by John O'Donnell, Cordelia Hall and Rex Page (Springer). Haskell is the implementation language, so effectively it is "Discrete Mathematics Using Haskell". It would be nice if someone wrote a geometry book using Haskell... ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Pretty-printer for Text
On 27 October 2010 18:39, Stephen Tetley wrote: > Having a Pretty class plus primitive printers int, bool is an > advantage. For ints, bools, ... code tends to look neater if you use > int or bool rather than pretty. Plus for ints and others you tend to > need things like hex printers anyway, so one size via a type class > doesn't fit all. Definitely agreed. > As for the class - if I have a reasonably sized > syntax tree I'd rather just do > >> pretty a > > ... than formulate a naming scheme like: > >> prettyExpr a What do you mean by "prettyExpr"? My main objection to having a Pretty type class is that when having a "reasonably sized syntax tree", aren't you likely to want to have your own custom printing variants rather than the ones in the pre-defined class? As such, does having a default class make sense if it isn't used? That said, 9 packages [1] do use prettyclass [2]... out of the 168 packages [3] that use pretty itself [4] (some of which implement their own Pretty class). [1]: http://bifunctor.homelinux.net/~roel/cgi-bin/hackage-scripts/revdeps/prettyclass-1.0.0.0#direct [2]: http://hackage.haskell.org/package/prettyclass [3]: http://bifunctor.homelinux.net/~roel/cgi-bin/hackage-scripts/revdeps/pretty-1.0.1.1#direct [4]: http://hackage.haskell.org/package/pretty -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Does it deserve to be a hackage package?
Hello haskellers, While ago I had a question about opening the url in the default browser from haskell program. I didn't get any immediate answers so I wrote my own solution. On Linux it uses xdg-open and on Windows - ShellExecute Api. Later I received a letter saying what similar functionality was recently implemented in trunk version of gtk2hs but is currently unavailable as binary package. Code I wrote works quite well for my purposes and I copied it into several my programs. In order to make maintenance easier I recently thought about uploading it to hackage. But given a wast amount of half-dead packages with intersecting functionality there I'd like to ask the opinion of community. Does such library look helpful to you? Dmitry ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Pretty-printer for Text
On 27 October 2010 08:57, Ivan Lazar Miljenovic wrote: > > What do you mean by "prettyExpr"? Without a type class I generally name pretty printers by the pretty 'pretty' then the type they print Expr (expression), Decl (declaration) etc. > My main objection to having a Pretty type class is that when having a > "reasonably sized syntax tree", aren't you likely to want to have your > own custom printing variants rather than the ones in the pre-defined > class? As such, does having a default class make sense if it isn't > used? > > That said, 9 packages [1] do use prettyclass [2]... out of the 168 > packages [3] that use pretty itself [4] (some of which implement their > own Pretty class). For a syntax tree I'd want a class, then I can use pretty at any level. This is helpful in defining the instances as most of the work is delegated to pretty rather than prettyExp, prettyDecl etc. so it keeps the code neat. It is also useful in GHCi where I can just call pretty on something. I can't think that I've ever wanted two different flavours of output for a syntax tree. If I was wanted 'round trip printing' (from parsing to pretty to parsing) I'd have to take a lot of care over white space and layout so I would be needing something more powerful than a pretty printer. As for the prettyclass in HughesPJ, if people found they wanted this I don't know why people didn't switch to wl-pprint. Wl-pprint is nicer in enough ways to make the change sensible. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Pretty-printer for Text
On 27 October 2010 19:19, Stephen Tetley wrote: > On 27 October 2010 08:57, Ivan Lazar Miljenovic > wrote: >> My main objection to having a Pretty type class is that when having a >> "reasonably sized syntax tree", aren't you likely to want to have your >> own custom printing variants rather than the ones in the pre-defined >> class? As such, does having a default class make sense if it isn't >> used? >> >> That said, 9 packages [1] do use prettyclass [2]... out of the 168 >> packages [3] that use pretty itself [4] (some of which implement their >> own Pretty class). > > For a syntax tree I'd want a class, then I can use pretty at any > level. This is helpful in defining the instances as most of the work > is delegated to pretty rather than prettyExp, prettyDecl etc. so it > keeps the code neat. It is also useful in GHCi where I can just call > pretty on something. Why not write your own Pretty class for that project then? Admittedly, some packages might write their own class because they didn't want to use non-ghc/platform libraries or prettyclass didn't exist then. I had to write my own [1] for two reasons: 1) I needed to be able to differentiate between quoted and un-quoted values, and 2) some of the ways values get pretty-printed are different than just "text . show", which is what all the default instances of the Pretty classes are (with the exception of String). It's this second point that I would wonder how many people would use a default Pretty class: just because I want to print String values one way, does that you mean you should print them that way as well? [1]: http://hackage.haskell.org/packages/archive/graphviz/2999.10.0.1/doc/html/Data-GraphViz-Printing.html#t:PrintDot > I can't think that I've ever wanted two different flavours of output > for a syntax tree. If I was wanted 'round trip printing' (from parsing > to pretty to parsing) I'd have to take a lot of care over white space > and layout so I would be needing something more powerful than a pretty > printer. Again, it's not a matter of two different types of output; it's a matter of my way of doing output differs from your way of doing output, even for in-built types. Don't forget, instances are imported and exported implicitly. -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Does it deserve to be a hackage package?
On 27 October 2010 10:13, Dmitry V'yal wrote: > While ago I had a question about opening the url in the default browser from > haskell program. I didn't get any immediate answers so I wrote my own > solution. On Linux it uses xdg-open and on Windows - ShellExecute Api. > Does it deserve to be a hackage package? If it's not in an existing small library, yes. If I have to have a dependency on gtk2hs just to do that, I'd rather have a small library. Does it work on OS X? If not, I'm sure someone would submit a patch for that. This can also be used for opening the file browser and such, right? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Help me TH code.
Unless you have a 'real' type for parse sometime during compile time, TH
won't be able to generate it. A good rule of thumbs is that if you can't
write the code yourself, then you can't get TH to do it either.
/J
On 27 October 2010 08:50, Andy Stewart wrote:
> Serguey Zefirov writes:
>
> > 2010/10/27 Andy Stewart :
> >> Hi all,
> >>
> >> I want use TH write some function like below:
> >>
> >> data DataType = StringT
> >>| IntT
> >>| CharT
> >>
> >> parse :: [(String,DataType)] -> (TypeA, TypeB, ... TypeN)
> >>
> >> Example:
> >>
> >> parse [("string", StringT), ("001", IntT), ("c", CharT)]
> >>
> >> will return:
> >>
> >> ("string", 001, 'c')
> >>
> >> So how to use TH write 'parse' function?
> >
> > I think that you should use TH properly, without compiler and logical
> errors.
> >
> > What actually do you want?
> I'm build multi-processes communication program.
>
> Example i have two processes : Client and Server.
>
> At Client side, i pass [DataType] to Server, example:
>
> [StringT, IntT, CharT]
>
> Server will handle "user input" with [DataType]
> and return result [String] to Client side, example:
>
> ["string", "001", "c"]
>
> Then at Client side, i need parse [String] to get real value:
>
> ("string", 001, 'c')
>
> Because, [DataType] have many different case, so i want pass [String]
> between processes, and use TH parse result [String] at Client side.
>
> Thanks,
>
> -- Andy
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>
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Re: [Haskell-cafe] Help me TH code.
2010/10/27 Andy Stewart :
> Serguey Zefirov writes:
>> I think that you should use TH properly, without compiler and logical errors.
>>
>> What actually do you want?
> I'm build multi-processes communication program.
You don't need TH here, I think.
You can write a class Ask:
class Ask a where ask :: YourMonad a
and then instance it:
instance Ask Int where ask = liftIO $ do { putStrLn "Enter integer:";
l <- getLine; return $ read l}
instance Ask Char where ask = liftIO $ do { putStrLn "Enter char:"; l
<- getLine; return $ head l}
instance Ask String where ask = liftIO $ do { putStrLn "Enter
string:"; l <- getLine; return l}
instance (Ask a, Ask b, Ask c) => Ask (a,b,c) where ask = liftIO $ do
{ a <- ask; b <- ask; c <- ask; return (a,b,c)}
You can pass ask values between processes, receiving results of asking.
TH is great and good, but it is that only when you absolutely
exhausted of usual Haskell options.
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[Haskell-cafe] Re: what is the status of haskell's mail libraries?
Hi Michael, thanks for the link and congratulations on your other work too. Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Haskell and a complete mail client lib?
Hi all, do we Haskellers have a complete Mail client library? One that goes beyond an unstructured byte string? Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] what is the status of haskell's mail libraries?
On Wed, 27 Oct 2010 04:46:07 +0200, Michael Snoyman wrote: I just release mime-mail[1], which can construct multipart messages. Note, that this will not run on Windows, as it gives command /usr/sbin/sendmail Regards, Henk-Jan van Tuyl -- http://Van.Tuyl.eu/ http://members.chello.nl/hjgtuyl/tourdemonad.html -- ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Pretty-printer for Text
On 27 October 2010 09:32, Ivan Lazar Miljenovic wrote: > Why not write your own Pretty class for that project then? Personally I don't like type classes if they're solely for notational convenience. I want them to be a least a convention and its nicer still when they genuinely represent something like Monad, Monoid, Applicative etc. The Pretty class in wl-pprint is a convention. If I'm using HughesPJ for compatibility I'll do without a type class, defining my own is just notational convenience. > Admittedly, some packages might write their own class because they > didn't want to use non-ghc/platform libraries or prettyclass didn't > exist then. > > I had to write my own [1] for two reasons: 1) I needed to be able to > differentiate between quoted and un-quoted values, and 2) some of the > ways values get pretty-printed are different than just "text . show", > which is what all the default instances of the Pretty classes are > (with the exception of String). It's this second point that I would > wonder how many people would use a default Pretty class: just because > I want to print String values one way, does that you mean you should > print them that way as well? If you were specifically working around issues of quoting, maybe there would have been room for an alternative design where an Identifier datatype had two constructors one for simple strings and one for quoted ones. In a nutshell, wl-pprint seems to have got the interface 'right' for my tastes. I like having both named primitive printers and a Pretty class. If I want printers for ShowS types or for Docs that don't need page formatting I always copy Wl-pprint's interface. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Pretty-printer for Text
On 27 October 2010 20:13, Stephen Tetley wrote: > On 27 October 2010 09:32, Ivan Lazar Miljenovic > wrote: > >> I had to write my own [1] for two reasons: 1) I needed to be able to >> differentiate between quoted and un-quoted values, and 2) some of the >> ways values get pretty-printed are different than just "text . show", >> which is what all the default instances of the Pretty classes are >> (with the exception of String). It's this second point that I would >> wonder how many people would use a default Pretty class: just because >> I want to print String values one way, does that you mean you should >> print them that way as well? > > If you were specifically working around issues of quoting, maybe there > would have been room for an alternative design where an Identifier > datatype had two constructors one for simple strings and one for > quoted ones. Well, in my case it's because Dot attributes need to have their values in quotes when they contain spaces, etc. As such, you have these situations: * ` DotNode 1 [Label $ StrLabel "foo"] ' is printed as ` 1 [label=foo] ' * ` DotNode 2 [Label $ StrLabel "bar baz"] ' is printed as ` 2 [label="bar baz"] ' Now, I _could_ have just quoted everything, but I tried to make the generated Dot code as "correct" as possible. > In a nutshell, wl-pprint seems to have got the interface 'right' for > my tastes. I like having both named primitive printers and a Pretty > class. If I want printers for ShowS types or for Docs that don't need > page formatting I always copy Wl-pprint's interface. OK, I'll keep the class in as well. What about my other queries (e.g. to keep SimpleDoc or not)? -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Does it deserve to be a hackage package?
Christopher Done writes: > On 27 October 2010 10:13, Dmitry V'yal wrote: >> While ago I had a question about opening the url in the default browser from >> haskell program. I didn't get any immediate answers so I wrote my own >> solution. On Linux it uses xdg-open and on Windows - ShellExecute Api. > >> Does it deserve to be a hackage package? > > If it's not in an existing small library, yes. If I have to have a > dependency on gtk2hs just to do that, I'd rather have a small library. > Does it work on OS X? If not, I'm sure someone would submit a patch > for that. This can also be used for opening the file browser and such, > right? It's APIs in GIO library (a sub-library in gtk2hs), you just need depend on GIO don't need depend any other library. Dmitry, it's unnecessary since GIO can do better with same experience both Windows and Linux, don't need any external program help. Infact, GIO not just call default browser for url, it can call any program to open any format. Example, you install many different PDF-Viewer in your system, it will return a Application list for *.pdf format...etc. Good news is, gtk2hs-0.12.0 has ready for release, we will wait one week, if no user report any bug of gtk2hs darcs, we will release. Then you can use it. Cheers, -- Andy ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] what is the status of haskell's mail libraries?
On Wed, Oct 27, 2010 at 10:39 AM, Henk-Jan van Tuyl wrote: > On Wed, 27 Oct 2010 04:46:07 +0200, Michael Snoyman > wrote: > >> I just release mime-mail[1], which can construct multipart messages. > > Note, that this will not run on Windows, as it gives command > /usr/sbin/sendmail The sendmail feature will not work on Windows (and you're right, I should document that more clearly). However, rendering of email messages is completely cross-platform, and there was some talk of getting either HaskellNet or SMTPClient to work with mime-mail, which would allow direct sending of email via SMTP. Michael ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Haskell and a complete mail client lib?
Günther Schmidt writes: > Hi all, > > do we Haskellers have a complete Mail client library? > > One that goes beyond an unstructured byte string? I want mail-client library too, for my gtk2hs project (http://www.flickr.com/photos/48809...@n02/) If still haven't complete mail-client library when i want build mail-client, i will write one. Please let me know if someone working on mail-client library, i want play. :) Cheers, -- Andy ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] who's in charge?
Hi all, this may be an odd question to some, but I think it's actually quite an un-extraordinary one. Who's in charge? Of Haskell I mean. If there was some alien from Planet Java to land on Planet Haskell and demand to be taken to our leader, whom would we take him to? Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] who's in charge?
2010/10/27 Günther Schmidt : > Hi all, > > this may be an odd question to some, but I think it's actually quite an > un-extraordinary one. > > Who's in charge? > > Of Haskell I mean. If there was some alien from Planet Java to land on > Planet Haskell and demand to be taken to our leader, whom would we take him > to? The Haskell' committee? -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] who's in charge?
Hi Ivan, there is a committee? Günther Am 27.10.10 12:37, schrieb Ivan Lazar Miljenovic: 2010/10/27 Günther Schmidt: Hi all, this may be an odd question to some, but I think it's actually quite an un-extraordinary one. Who's in charge? Of Haskell I mean. If there was some alien from Planet Java to land on Planet Haskell and demand to be taken to our leader, whom would we take him to? The Haskell' committee? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] who's in charge?
2010/10/27 Günther Schmidt : > Hi Ivan, > > there is a committee? Sure is: http://hackage.haskell.org/trac/haskell-prime/ -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANN: Chart v0.14
I'm pleased to announce v0.14 of the haskell chart library. This is a library for drawing 2D data plots. It's features include + Use of the cairo graphics engine, supporting a variety of output types: ps, pdf, png, and gtk windows. + A variety of plot types, including: points, lines, error bars, candlesticks, bar charts and pie charts. + Strong typing. Charts are parameterized by the types of their coordinates. One benefit of this is that labels etc are automatically generated appropriately for the type of the data. Currently axis types include: Double, Int, Log, LocalTime, and Indexed. + (some) support for interactivity. Charts support dynamic resizing, and mapping from device coordinates back to source values. The library is available on hackage. Additional information including details of the mailing list can be found here: http://dockerz.net/software/chart.html Thanks to Malcolm Wallace, Eugene Kirpichov, and Matt Brown for their contributions to this release. Tim Docker -- New features in v0.14 - * Plot Type: AreaSpots4D Spots with varying area and colour * Plot Type: CandleStick charts A specific type of plot often used in financial markets for stock price series. * Multiline text in Annotation Plots with flexible control over the anchoring. * Picking. The library now contains logic required to map device coordinates back to input elements. This facilitates interactivity. See tests/TestPicking.hs. * Multiple Layers of axis labels This is currently used by the LocalTime axis to show an additional set of context labels - these show the next sensible granularity of time enclosing the more detailed labels and ticks. * Avoid overlapping axis labels The axis rendering code now skips labels where there would be overlaps. This is done dynamically as the chart is rendered. * Code refactor Plots and axes have been split into separate file hierarchies, with one file per type. This makes it easier to understand, and (hopefully) makes it clearer how to add new plot types. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: ANN: Chart v0.14
Good news! Thanks, Tim! I'd like to also note that now the LocalTime axis supports millisecond precision, whereas earlier it only supported second precision. 2010/10/28 Tim Docker : > I'm pleased to announce v0.14 of the haskell chart library. This is a > library for drawing 2D data plots. It's features include > > + Use of the cairo graphics engine, supporting a variety of > output types: ps, pdf, png, and gtk windows. > > + A variety of plot types, including: points, lines, error bars, > candlesticks, bar charts and pie charts. > > + Strong typing. Charts are parameterized by the types of their > coordinates. One benefit of this is that labels etc are > automatically generated appropriately for the type of the > data. Currently axis types include: Double, Int, Log, LocalTime, > and Indexed. > > + (some) support for interactivity. Charts support dynamic > resizing, and mapping from device coordinates back to source > values. > > The library is available on hackage. Additional information including > details of the mailing list can be found here: > > http://dockerz.net/software/chart.html > > Thanks to Malcolm Wallace, Eugene Kirpichov, and Matt Brown for their > contributions to this release. > > Tim Docker > > -- > > New features in v0.14 > - > > * Plot Type: AreaSpots4D > Spots with varying area and colour > > * Plot Type: CandleStick charts > A specific type of plot often used in financial markets for stock > price series. > > * Multiline text in Annotation Plots > with flexible control over the anchoring. > > * Picking. > The library now contains logic required to map device coordinates back > to input elements. This facilitates interactivity. See tests/TestPicking.hs. > > * Multiple Layers of axis labels > This is currently used by the LocalTime axis to show an additional set > of context labels - these show the next sensible granularity of time > enclosing the more detailed labels and ticks. > > * Avoid overlapping axis labels > The axis rendering code now skips labels where there would be > overlaps. This is done dynamically as the chart is rendered. > > * Code refactor > Plots and axes have been split into separate file hierarchies, with one file > per type. This makes it easier to understand, and (hopefully) makes it > clearer how to add new plot types. > > > > > -- > You received this message because you are subscribed to the Google Groups > "Haskell Charts" group. > To post to this group, send email to haskell-cha...@googlegroups.com. > To unsubscribe from this group, send email to > haskell-charts+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/haskell-charts?hl=en. > > -- Eugene Kirpichov Senior Software Engineer, Grid Dynamics http://www.griddynamics.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] cross-platform compile
On Tue, Oct 26, 2010 at 9:51 PM, Hong Yang wrote: > Just curious if Haskell can or will generate cross-platform executable code, > e.g., generate code for Linux from a Windows machine. > > Thanks, > > Hong I don't know about other compilers, but at least GHC is not quite there yet: http://www.haskell.org/pipermail/glasgow-haskell-users/2010-June/018893.html In my experience, compiling for Windows on Linux, setting up the Windows release GHC itself for running on Wine is easy enough. Libraries can be a lot more fiddly - for instance my rather avant-garde msys-on-wine setup didn't play well with the configure script in the network package so I had to install it on msys-on-Windows. Be ready to set up your PATH yourself, fiddle with linker flags, and remember that the gcc version that comes with the current GHC Windows release is still 3.4.5. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [ANNAUNCE] ghcjs-0.1.0 Haskell to Javascript compiler
On 21-10-10 01:01, Victor Nazarov wrote:
I've been working on this for some month and I think now I'm ready to
share the results.
Great stuff! I've been looking for something like this for a long time.
If you add "|| transport.status == 0" to line 90 of
examples/rts-common.js, it also works on a local file system.
I played around with it a bit to see how easy it was to call JavaScript
from Haskell, and it turned out to be straightforward. With a little
guessing, I constructed a JavaScript representation of a thunk, which
evaluates its string argument as a JavaScript expression and returns the
resulting string to Haskell. This thunk can be passed to the
JavaScript-compiled Haskell function. To pass it around in Haskell and
force its evaluation, I constructed a simple monad.
Now, on your web page, you can do something like:
and in a Haskell module:
validate :: JS ()
validate =
do { inputValue <- eval "document.getElementById('inputField').value"
; exec $
"document.getElementById('inputField').style.backgroundColor="++
color inputValue
}
where color str = if and (map isDigit str) then "'white'" else "'red'"
This example creates a text field that turns red if it contains any
non-digit characters. It is on-line at
http://tryout.oblomov.com/ghcjs/ghcjs.html (Note: I only tested it on
Firefox on a Mac)
All used files are in a zip file at
http://tryout.oblomov.com/ghcjs/ghcjs.zip (validate is in Test.hs, the
JS monad in JS.hs, and the JavaScript for execHaskell in util.js)
Cheers,
Martijn Schrage -- Oblomov Systems
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[Haskell-cafe] ANN: timeplot-0.2.1, a tool for visualizing time series from log files.
Hi cafe, I'm pleased to announce timeplot-0.2.1. http://hackage.haskell.org/package/timeplot This is a tool for visualizing time series from log files. I'm myself using it for diagnosing performance of distributed systems: I aggregate their logs and plot various things, such as the number of tasks executing on each machine of the cluster, or quantiles of database query times, etc. See pretty pictures on haskellwiki: http://www.haskell.org/haskellwiki/Timeplot This version has several changes, which together raised the program's usefulness for me tremendously: - The program now builds and works on Windows! You just need gtk2hs. I got rid of strptime and pcre dependencies (strptime is built from bundled and patched source, and I use regex-tdfa by Chris Kuklewicz). - Support for millisecond precision on charts (thanks to the new 0.14 version of Tim Docker's excellent Chart library) - Support for millisecond precision in input (because I re-did strptime to compile from scratch with support for the %OS pattern, which recognizes fractional seconds) - Support for selecting a range of the input (however, non-interactively) with "-fromTime/-toTime" - Support for "duration" plots: given an event track (where events of something beginning or ending are recorded), you can produce all kinds of plots over the durations of these events. - Support for colored "status" plots: now event tracks represent not purely the presence or absence of an active event, but an event track can be colored, representing several states of a subsystem or subprocess. Please use the program and provide feedback :) I have a hope that it could become a reasonably widely used tool for the kinds of tasks that I use it for. -- Eugene Kirpichov Senior Software Engineer, Grid Dynamics http://www.griddynamics.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] who's in charge?
2010/10/27 Ivan Lazar Miljenovic : > 2010/10/27 Günther Schmidt : >> Hi all, >> >> this may be an odd question to some, but I think it's actually quite an >> un-extraordinary one. >> >> Who's in charge? >> >> Of Haskell I mean. If there was some alien from Planet Java to land on >> Planet Haskell and demand to be taken to our leader, whom would we take him >> to? > > The Haskell' committee? They're just figureheads for a shadowy cabal :-D -- Dougal Stanton dou...@dougalstanton.net // http://www.dougalstanton.net ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] who's in charge?
On Wed, 27 Oct 2010 14:13:31 +0100, you wrote: >They're just figureheads for a shadowy cabal :-D You mean the Haskelluminati? -Steve Schafer ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [ANNAUNCE] ghcjs-0.1.0 Haskell to Javascript compiler
I ran into a problem with line 31 of examples/rts-common.js when running on
Chrome:
>var word16addCarry = function function(a, b, c) {
Shouldn't that be:
>var word16addCarry = function(a, b, c) {
With that change it runs fine for me (GHC 6.12.3). Chrome also wasn't happy
loading from the local file system (Cross origin requests are only supported
for HTTP), so I just used happstack to test:
>import Happstack.Server
>main = simpleHTTP nullConf (fileServe [] "./")
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Re: [Haskell-cafe] who's in charge?
Who's in charge? If you mean the language, then the Haskell-prime committee is in charge. If you mean the compiler everyone uses (de-facto), then the two Simons are in charge. If you mean the website, online resources, and money earned from GSoC or donated, then there is a committee being set up right now to decide policy on those kinds of things. If you mean academic research into Haskell, then of course no-one is in charge, and everyone does what they see fit (and can get funding for). But there is a steering committee for the annual Haskell Symposium. There are also other bodies like the Industrial Haskell Group, who will typically have some small committee in charge of their (more restricted) focus area. Regards, Malcolm ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] who's in charge?
Hi Malcolm, well if I would like to point out that, for instance, Haskell exists for a lot more than 10 years now, and that, while the language per se rocks, and there are cool tools (cabal) and libraries (list, Set, Map), there still isn't even a mail client library, I wonder whom to escalate this to, and who is going to do something about it. I understand some parties wish to avoid success at all costs, while others, commercial users, benefit from the edge haskell gives them already and which probably can help themselves in case of, again, for instance a missing mail client library. And then there is the ones like me, which also want to benefit from the edge Haskell gives them over users of other languages and want to develop Real World Apps and who cannot easily help themselves in case of a missing mail client library. So while there are many aspects of the future of haskell, who effectively is it that steers the boat? Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Pretty-printer for Text
On Tue, Oct 26, 2010 at 9:50 PM, Ivan Lazar Miljenovic wrote: > I'm currently working on a pretty-printer for lazy text [1] values, > basing the API on the wl-pprint [2] package. > > [1]: http://hackage.haskell.org/package/text > [2]: http://hackage.haskell.org/package/wl-pprint > > In terms of API decisions, there are a few things I'm not sure of and > am wondering what other people would prefer: > > * Should the SimpleDoc type still be exported? Or should the > rendering functions just return a Builder or lazy Text value? I'm not really sure what you're asking here, but I find BS Builders pretty convenient to work with. A recent release of 'text' includes a Builder type. > > * Is the Pretty class wanted/needed? If so, should the individual > combinators (int, bool, etc.) be kept or just use "pretty" for > everything? I frequently write a 'Pretty' class when writing complex ASTs, but I have never found it to be a hardship. I prefer using well-named combinators for primitive types. > > * Should String values be catered for or just have everything be Text-based? The OverloadedStrings language extension solves the most common case for wanting to have string-based pretty-printer functions. Antoine ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [ANNAUNCE] ghcjs-0.1.0 Haskell to Javascript compiler
On Wed, Oct 27, 2010 at 4:30 PM, Martijn Schrage wrote:
> On 21-10-10 01:01, Victor Nazarov wrote:
>>
>> I've been working on this for some month and I think now I'm ready to
>> share the results.
>
> Great stuff! I've been looking for something like this for a long time.
>
> If you add "|| transport.status == 0" to line 90 of examples/rts-common.js,
> it also works on a local file system.
>
Thank you, I'll fix it.
> I played around with it a bit to see how easy it was to call JavaScript from
> Haskell, and it turned out to be straightforward. With a little guessing, I
> constructed a JavaScript representation of a thunk, which evaluates its
> string argument as a JavaScript expression and returns the resulting string
> to Haskell. This thunk can be passed to the JavaScript-compiled Haskell
> function. To pass it around in Haskell and force its evaluation, I
> constructed a simple monad.
>
Very cool. I'll incorporate your changes, If you don't mind.
However, I have some minor remarks.
You shouldn't override hscall function, or you may break partial
application implementation. And you shouldn't overide properties of
evalFn, I wonder that this doesn't break your example...
var evalFn = new $hs.Func(1);
evalFn.evaluate(arg) = function(arg) {
var argStr = $hs.fromHaskellString(arg);
var res = eval(argStr);
return $hs.toHaskellString(arg); // This function should be added to
$hs object/namespace
}
> Now, on your web page, you can do something like:
>
>
>
> and in a Haskell module:
>
> validate :: JS ()
> validate =
> do { inputValue <- eval "document.getElementById('inputField').value"
> ; exec $ "document.getElementById('inputField').style.backgroundColor="++
> color inputValue
> }
> where color str = if and (map isDigit str) then "'white'" else "'red'"
>
I think we should do something like this:
data JsObject = ... -- Should be made abstract
and
eval :: String -> [JsObject] -> JS JsObject
So we can pass around javascript-objects in haskell program and bind
them back into javascript calls.
And use some conversion functions in case when we need data:
jsObjectToString :: JsObject -> JS String
jsObjectToInt :: JsObject -> JS Int
--
Victor Nazarov
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Re: [Haskell-cafe] [ANNAUNCE] ghcjs-0.1.0 Haskell to Javascript compiler
On Wed, Oct 27, 2010 at 5:25 PM, Ryan Yates wrote:
> I ran into a problem with line 31 of examples/rts-common.js when running on
> Chrome:
>> var word16addCarry = function function(a, b, c) {
> Shouldn't that be:
>> var word16addCarry = function(a, b, c) {
Yes, that's my fault. I'll fix it.
> With that change it runs fine for me (GHC 6.12.3). Chrome also wasn't happy
> loading from the local file system (Cross origin requests are only supported
> for HTTP), so I just used happstack to test:
>> import Happstack.Server
>> main = simpleHTTP nullConf (fileServe [] "./")
>
>
I wasn't able to run it in Chrome without dedicated HTTP-server, seems
like it is the only way...
--
Victor Nazarov
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Re: [Haskell-cafe] [ANNAUNCE] ghcjs-0.1.0 Haskell to Javascript compiler
> > I wasn't able to run it in Chrome without dedicated HTTP-server, seems > like it is the only way... > > It looks like running Chrome with the flag: -allow-file-access-from-files lets it work. Thanks for making this project, I'm looking forward to more! Ryan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] If Python now has a good email library; how challenging is it to call Python from Haskell?
:) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] If Python now has a good email library; how challenging is it to call Python from Haskell?
How does python having an e-mail library change the situation with calling Python from Haskell? On Wed, Oct 27, 2010 at 10:43 AM, wrote: > :) > > > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] If Python now has a good email library; how challenging is it to call Python from Haskell?
On 27 October 2010 19:46, Thomas DuBuisson wrote: > How does python having an e-mail library change the situation with > calling Python from Haskell? He's commenting, presumably, on the apparently disparate nature of Haskell email libraries and the fortuitousness therefore of Python having a describadly good email library, not that this changes the difficulties in interfacing with Python in general. On 27 October 2010 19:43, wrote: > :) glguy's Github interfaces with Python; it involves some C, naturally, but it's not complicated: http://github.com/glguy/hpaste ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell and a complete mail client lib?
gue.schmidt: > Hi all, > > do we Haskellers have a complete Mail client library? As always, look on Hackage: http://www.google.com/search?hl=en&as_sitesearch=hackage.haskell.org/package&as_q=email ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] If Python now has a good email library; how challenging is it to call Python from Haskell?
Are there any C libraries that you can use? I did a google search on email client in c and failed in an epic fashion but I figure parts of sendmail or mutt could be used. -deech On Wed, Oct 27, 2010 at 12:55 PM, Christopher Done wrote: > On 27 October 2010 19:46, Thomas DuBuisson > wrote: > > How does python having an e-mail library change the situation with > > calling Python from Haskell? > > He's commenting, presumably, on the apparently disparate nature of > Haskell email libraries and the fortuitousness therefore of Python > having a describadly good email library, not that this changes the > difficulties in interfacing with Python in general. > > On 27 October 2010 19:43, wrote: > > :) > > glguy's Github interfaces with Python; it involves some C, naturally, > but it's not complicated: http://github.com/glguy/hpaste > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: If Python now has a good email library; how challenging is it to call Python from Haskell?
Am 27.10.10 19:43, schrieb cas...@istar.ca: :) Well I was considering using a foreign library too for email. It creates a whole lot of dependencies, so I'd prefer to be able to do it entirely in Haskell instead. I was also wondering if it's possible to create a DSL for the email stuff and then use different interpreters for such terms which could evaluate to calling foreign lib (on Windows possibly MAPI). Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Need programming advice for Network Protocol Parsing
Hi all, I'd like to write a client app that communicates with a server over TCP/IP. My question is in regard which parser to use for the servers responses. I'm quite familiar with parsec (2.x) but I'm not sure if it's the right choice for this. The code would necessarily constantly be switching between checking for input, interpreting and then responding. Any suggestions? Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] If Python now has a good email library; how challenging is it to call Python from Haskell?
Don't know, but probably challenging enough to make it worth challenging the assumption that Python now has a good email library. >From a cursory look at the 3.0 library documentation, it looks to me like IMAP support still means the old imaplib module. That's pretty rudimentary, compared to the HaskellNet IMAP support. Donn Cave, d...@avvanta.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Need programming advice for Network Protocol Parsing
2010/10/27 Günther Schmidt : > My question is in regard which parser to use for the servers responses. I'm > quite familiar with parsec (2.x) but I'm not sure if it's the right choice > for this. The code would necessarily constantly be switching between > checking for input, interpreting and then responding. Attoparsec is kind of made for this: http://hackage.haskell.org/package/attoparsec ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell and a complete mail client lib?
2010/10/27 Don Stewart : > gue.schmidt: >> Hi all, >> >> do we Haskellers have a complete Mail client library? > > As always, look on Hackage: > > > http://www.google.com/search?hl=en&as_sitesearch=hackage.haskell.org/package&as_q=email Besides the tagged packages, there are a few other places one could look if one searched the package listings carefully: - http://hackage.haskell.org/package/HaskellNet - http://hackage.haskell.org/package/postmaster - http://hackage.haskell.org/package/pop3-client Are any of these *complete*? Dunno. But I suspect you do not actually need to do everything one could possibly do with email. -- gwern http://www.gwern.net ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] If Python now has a good email library; how challenging is it to call Python from Haskell?
On Oct 27, 2010, at 12:43 PM, cas...@istar.ca wrote: > :) I will point out that "Python Haskell Interface" has an excellent axiom. Unfortunately, my attempt to write a nice wrapper around the Python FFI foundered years ago chasing segfaults. It doesn't seem like it should be too hard, if you get the reference counting right - and tie everything to the GIL (ick). ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] who's in charge?
On 10-10-27 06:31 AM, Günther Schmidt wrote: this may be an odd question to some, but I think it's actually quite an un-extraordinary one. Who's in charge? Of Haskell I mean. If there was some alien from Planet Java to land on Planet Haskell and demand to be taken to our leader, whom would we take him to? This is in many ways (more ways than I expect) like: How to do the visitor pattern? If a visitor from Java landed on Haskell and wanted to do the visitor pattern? Of course, to be fair, there are also converses: How to define infix operators in Java? If a visitor from Haskell landed on Java and wanted to define his/her own infix operators? You just can't shoehorn one model into another. You can't shoehorn one language model into another, but more importantly, you can't shoehorn one community model into another. Some people, when confronted with the problem of lacking a library, say "I know, a leader would make sure the library happens". Now they have a bigger problem. The leader might instead make sure that the library will never happen. Python has a leader, no? This leader has suppressed much-needed libraries and much-needed alternative implementations. Examples are cycle-robust GC and stackless function calls. There are libraries on Hackage that I am pretty sure a leader of Haskell would have killed. A leader of Haskell who would take "avoid success at all costs" too seriously would kill all of Hackage and censor the word "Cabal". ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Need programming advice for Network Protocol Parsing
I'm occasionally working on making a friendly yet performant library that simultaneously builds parsers and generators, but it's non-trivial. If you want to see the general idea, there's a Functional Pearl on pickler combinators from a few years back that you can probably play with. But for a real network protocol that you need to implement today, I'd go with attoparsec or Data.Binary. 2010/10/27 Günther Schmidt > Hi all, > > I'd like to write a client app that communicates with a server over TCP/IP. > > My question is in regard which parser to use for the servers responses. I'm > quite familiar with parsec (2.x) but I'm not sure if it's the right choice > for this. The code would necessarily constantly be switching between > checking for input, interpreting and then responding. > > Any suggestions? > > Günther > > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Haskell and a complete mail client lib?
Hi Don, thank your this link. Also thank you for supplying a link to this page http://www.reddit.com/r/haskell_proposals/top/?t=year in another message, some time back. I can see that checking there first would have made my entire post redundant. Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] concurrency vs. I/O in GHC
On 27/10/2010 05:00 PM, John Lato wrote: I am somewhat surprised that all capabilities must be ready for GC; I thought with the parallel GC that wouldn't be necessary. But I don't know much about GC implementations so I try not to let their behavior surprise me too much. GHC has a _parallel_ GC implementation, meaning that the GC event runs in parallel on several cores. But it does not (yet) have _concurrent_ GC, meaning that a GC event can happen at the same time as Haskell threads are running. (Basically, which Haskell code running, the references between objects could change while the GC engine is trying to analyse them, which would be Bad.) I understand that the developers are actively working on fixing this, since it can sometimes have a significant effect on the performance of multicore programs... ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] who's in charge?
On 28/10/2010, at 4:38 AM, Günther Schmidt wrote: > As we are 10+ years now still without one of the most essential libraries any > programming language needs I guess it's not that easy. It has just been > recently that I wanted to do email via haskell. I was very surprised not find > one in place already. There is no standard E-mail library for Ada, Fortran, COBOL, PL/I, or a great many languages. Fortran and COBOL have been around for fifty years, not ten. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] On being called a troll
Hi everyone, this post is to argue my own case. Today I have made the most upsetting experience of being called a troll, twice. I have posted to this list for over 3 years now and until lately it was an enlightening experience. The responses to my questions have usually been helpful and friendly. But for some time now, I have noticed that the tone on this list has changed. It seems to have become ok to respond quite brutally and without regard for the other persons feelings. It also seems to have become ok to chime in. For some reason it has become acceptable to politicalize a subject at the earliest convenience and take the gloves off. I am 42 now and am surprised how much this still hurts, after all I survived the schoolyard bullies and who would have thought that these times would ever come again? I urge you, my fellow haskellers, to show some restraint when we are dealing with one another on this list. And to think twice before you launch a personal attack. Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] who's in charge?
Careful. That might draw some unwarranted comparisons :) -deech 2010/10/27 Richard O'Keefe > > On 28/10/2010, at 4:38 AM, Günther Schmidt wrote: > > As we are 10+ years now still without one of the most essential libraries > any programming language needs I guess it's not that easy. It has just been > recently that I wanted to do email via haskell. I was very surprised not > find one in place already. > > There is no standard E-mail library for Ada, Fortran, COBOL, PL/I, or a > great many > languages. Fortran and COBOL have been around for fifty years, not ten. > > > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Where has GDK.GC gone?
Today I noticed a small but interesting fact: Under Gtk2hs 0.10.x, the module Graphics.UI.Gtk re-exports (amoung countless others) the module Graphics.UI.Gtk.Gdk.GC. However, under Gtk2hs 0.11.x, it does not. After downloading the darcs repo (with took forever, by the way), I discovered that the requisit line still exists in the source code, but it has been commented out. My repeated attempts to force Darcs to tell me exactly which patch did this resulted only in Darcs locking up again and again. (I'm quite surprised at that. Usually all Darcs operations are instantaneous. I guess the local repo is corrupt somehow or something...) So anyway, what I'd like to know is... was this alteration intensional? Or was it just an oversight? PS. The link on the website that says "browse the darcs repo online"? Apache just returns 404 at me. This is not particularly helpful. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] New repo location for the network package
Hi all, To ease my maintenance burden, I've moved the network package repo to: http://github.com/haskell/network Patches are accepted either in the git mbox format, as normal (diff) patch files, or as GitHub pull requests. P.S. If you want to get added to the haskell GitHub organization, just drop me an email. Johan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] On being called a troll
Günther, On 10/27/2010 05:12 PM, you wrote: For some reason it has become acceptable to politicalize a subject at the earliest convenience and take the gloves off. You were the first offender, when you wrote the following: "since there is no mail client library even after 10+ years I suggest to rethink the approach, because frankly, it's not working." Nobody provoked this comment, it was apparently a result of nothing more than your rather immature frustration at being unable to immediately obtain a free library to satisfy your needs with little effort on your part. "Trolling" is one of the kinder words that could be used to describe such behavior. I urge you, my fellow haskellers, to show some restraint when we are dealing with one another on this list. It would help your own credibility if you would acknowledge your own role in the matter before calling for others to show restraint. If you were to follow your own advice, you wouldn't need to be posting comments like this. Anton ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Need programming advice for Network ProtocolParsing
I'm occasionally working on making a friendly yet performant library that simultaneously builds parsers and generators, but it's non-trivial. If you I'm probably missing something in the "friendly yet performant" requirements, but I never quite understood the difficulty: A typical translation of grammar to parser combinators has very little code specific to "parsing" - it is mostly encoding the grammar in a coordination framework that calls on literal parsers at the bottom. Since the coordination framework uses some form of state transformers, exchanging the literal parsers with literal unparsers should turn the grammar parser into a grammar unparser (in essence, the non-terminal code is reusable, the terminal code is specific to the direction of data flow). Add switch-points (where the "mode" can switch from parsing to unparsing and back), and one has syntax-directed editors (here you need to be able to restart the process on arbitrary non-terminals), or expect-like protocol-driven computations (two or more agents with complementary views of which parts of the grammar involve parsing and which unparsing). The non-trivial parts I remember are to ensure that the unparser is directed by the AST (unless you want to generate random sentences from the whole language), just as the parser is directed by the input String, and not biasing the combinator framework towards parsing (which happens all too easily). But then, it has been a long time since I wrote such parser/unparsers (the first before Monads and do-notation became must-have aspects of combinator parsers, when we were free just to "make it work";-). It would be useful to have an overview of the issues that lead to the widespread view of this being non-trivial (other than in the narrow interpretation of "non-trivial" as "needs some code"). I've always wondered why there was so much focus on just parsing in combinator libraries. Just curious, Claus ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] If Python now has a good email library; how challenging is it to call Python from Haskell?
> From: Brandon Moore > On Oct 27, 2010, at 12:43 PM, cas...@istar.ca wrote: > > :) > > I will point out that "Python Haskell Interface" has an excellent axiom. >Unfortunately, my attempt to write a nice wrapper around the Python FFI >foundered years ago chasing segfaults. It doesn't seem like it should be too >hard, if you get the reference counting right - and tie everything to the GIL >(ick). Quite a typo. That should be "an excellent abbreviation" (PHI). Brandon ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Haskell Weekly News: Issue 156 - October 27, 2010
Welcome to issue 156 of the HWN, a newsletter covering developments in the [1]Haskell community in the week of October 17 - 28. I did not manage to filter out good posts from Haskell-Cafe this week. If you see a thread in -cafe that you think would be good to share with the community, please do share it with me. I need to find a better way of keeping up with the mountain of posts to that list. There were a total of 34 new stories posted to the Haskell Reddit channel (+10), 47 new questions taged with Haskell in StackOverflow (+20), and 332 messages posted to Haskell-Cafe (-76). So, what was hot last week? Announcements John Hughes [2]announced that the Functional Programming group at Chalmers is recruiting a postdoctoral researcher for a two year position, starting as soon as possible. Wouter Swierstra [3]called for workshop and co-located event proposals for the ICFP 2011 in Tokyo, Japan. Zhong Shao [4]informed us that the Department of Computer Science at Yale University is seeking applicants for a PostDoc and PhD positions in the broad area of certified software. Josh Tripplett wrote in to tell us about Ore, a [5]packaging system for Ruby inspired by Haskell's Cabal! According to [6]this haskell community calendar, there are 2 events to take note happening next week: The Haskell Communities & Activities Report submission deadline on Nov 1, and BelHac (in Ghent, Belgium) on Nov 5 - 7. Top Reddit Stories * The Haskell Platform is now in Ubuntu Domain: packages.ubuntu.com Score: 58, Comments: 5 On Reddit: http://www.reddit.com/r/haskell/comments/dtffi/the_haskell_platform_is_now_in_ubuntu/ Original: http://packages.ubuntu.com/maverick/haskell-platform * ghcjs: Haskell to Javascript: now released Domain: github.com Score: 36, Comments: 4 On Reddit: http://www.reddit.com/r/haskell/comments/dujnb/ghcjs_haskell_to_javascript_now_released/ Original: http://github.com/sviperll/ghcjs#readme * GHC Blog: New directions for Template Haskell Domain: hackage.haskell.org Score: 32, Comments: 3 On Reddit: http://www.reddit.com/r/haskell/comments/dtav8/ghc_blog_new_directions_for_template_haskell/ Original: http://hackage.haskell.org/trac/ghc/blog/Template%20Haskell%20Proposal * A brief tale of faster equality Domain: serpentine.com Score: 27, Comments: 10 On Reddit: http://www.reddit.com/r/haskell/comments/dt76u/a_brief_tale_of_faster_equality/ Original: http://www.serpentine.com/blog/2010/10/19/a-brief-tale-of-faster-equality/ * MTL 2.0 has been uploaded good bye old mtl, hello monads-fd! Domain: hackage.haskell.org Score: 25, Comments: 6 On Reddit: http://www.reddit.com/r/haskell/comments/dx8ml/mtl_20_has_been_uploaded_good_bye_old_mtl_hello/ Original: http://hackage.haskell.org/package/mtl-2.0.0.0 * Haskell Rapid Transit Domain: mtnviewmark.wordpress.com Score: 23, Comments: 4 On Reddit: http://www.reddit.com/r/haskell/comments/duqp0/haskell_rapid_transit/ Original: http://mtnviewmark.wordpress.com/2010/10/21/haskell-rapid-transit/ * mathblog: A program for creating and managing a static, mathematically-inclined weblog Domain: hackage.haskell.org Score: 20, Comments: 0 On Reddit: http://www.reddit.com/r/haskell/comments/duh1o/mathblog_a_program_for_creating_and_managing_a/ Original: http://hackage.haskell.org/package/mathblog-0.2 * Lazy Type-Level Programming: nice trick by Max Bolingbroke Domain: haskell.org Score: 20, Comments: 1 On Reddit: http://www.reddit.com/r/haskell/comments/duu54/lazy_typelevel_programming_nice_trick_by_max/ Original: http://www.haskell.org/pipermail/haskell-cafe/2010-October/085307.html * Let's build a compiler (in Haskell): Part 12 - Introducing the State Monad Domain: alephnullplex.appspot.com Score: 19, Comments: 14 On Reddit: http://www.reddit.com/r/haskell/comments/du38c/lets_build_a_compiler_in_haskell_part_12/ Original: http://alephnullplex.appspot.com/blog/view/2010/10/19/lbach-introducing-the-state-monad * What's the status of Haskell on the iPhone? Domain: self.haskell Score: 18, Comments: 5 On Reddit: http://www.reddit.com/r/haskell/comments/dsyij/whats_the_status_of_haskell_on_the_iphone/ Original: /r/haskell/comments/dsyij/whats_the_status_of_haskell_on_the_iphone/ Top StackOverflow Questions * Question (votes: 33, answers: 8): Best explanation for Languages without Null Read on SO: http://stackoverflow.com/questions/3989264/best-explanation-for-languages-without-null * Question (votes: 16, answers: 6): Saving my running toplevel for later Read on SO: http://stackoverflow.com/questions/3966925/saving-my-running-toplevel-for-later * Question (votes: 10, answers: 2): What's the difference between undefined in Haskell and null in Java? Read on SO: http://stackoverfl
Re: [Haskell-cafe] On being called a troll
2010/10/27 Günther Schmidt : > Hi everyone, > > this post is to argue my own case. > > Today I have made the most upsetting experience of being called a troll, > twice. > > I have posted to this list for over 3 years now and until lately it was an > enlightening experience. The responses to my questions have usually been > helpful and friendly. > > But for some time now, I have noticed that the tone on this list has > changed. It seems to have become ok to respond quite brutally and without > regard for the other persons feelings. It also seems to have become ok to > chime in. For some reason it has become acceptable to politicalize a subject > at the earliest convenience and take the gloves off. > I'm in favor of keeping personal accusations off of this list. Calling someone a troll on a public list isn't really helpful to the conversation. In extreme cases, I think some folks have the ability to moderate the list - so it isn't like we need to resort to public personal attacks to keep the discussion productive. > I am 42 now and am surprised how much this still hurts, after all I survived > the schoolyard bullies and who would have thought that these times would > ever come again? > > I urge you, my fellow haskellers, to show some restraint when we are dealing > with one another on this list. And to think twice before you launch a > personal attack. > > Günther > > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Red links in the new haskell theme
Hi Cafe, I really liked the new colors of haskell theme, but... Is really red a good color for links? At least for me, red links looks like broken or already visited ones. And the worst is hackage docs. It is really eye tiring to read. It's just a thought. Maybe it just with me. What about you? []s Victor___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Need programming advice for Network ProtocolParsing
On Oct 27, 2010, at 6:23 PM, Claus Reinke wrote: >> I'm occasionally working on making a friendly yet performant library that >> simultaneously builds parsers and generators, but it's non-trivial. If you > > I'm probably missing something in the "friendly yet performant" > requirements, but I never quite understood the difficulty: > > A typical translation of grammar to parser combinators has very > little code specific to "parsing" - it is mostly encoding the grammar > in a coordination framework that calls on literal parsers at the > bottom. Since the coordination framework uses some form of > state transformers, exchanging the literal parsers with literal > unparsers should turn the grammar parser into a grammar > unparser (in essence, the non-terminal code is reusable, the > terminal code is specific to the direction of data flow). On this topic, folks might be interested in the awesome "Invertible Syntax Descriptions" paper presented by Tillmann Rendel and Klaus Ostermann at this year's Haskell Symposium: http://www.informatik.uni-marburg.de/~rendel/unparse/ Cheers, Sterl___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
