from:"andrew"

I've got a piece of code that looks like this:

baselineContextSSL :: IO SSLContext
baselineContextSSL = do
ctx - SSL.context
SSL.contextSetDefaultCiphers ctx
#if defined __MACOSX__
SSL.contextSetVerificationMode ctx SSL.VerifyNone
#elif defined __WIN32__
SSL.contextSetVerificationMode ctx SSL.VerifyNone
#else
SSL.contextSetCADirectory ctx /etc/ssl/certs
SSL.contextSetVerificationMode ctx $
SSL.VerifyPeer True True Nothing
#endif
return ctx

all very nice (this being necessary because apparently the non-free
operating systems don't store their certs in a reliably discoverable
place; bummer).

That, however, is not the problem. After all, this sort of thing is what
#ifdefs are for. The problem is needing to get an appropriate symbol
based on what OS you're using defined.

I naively assumed there would be __LINUX__ and __MACOSX__ and __WIN32__
defined by GHC because, well, that's just the sort of wishful thinking
that powers the universe.

So my question is: what's an appropriate Haskell mechanism for building
code that is OS / arch  / distro specific? It's not like I have autoconf
running generating me a config.h I could #include, right?

This feels simple and an appropriate use of CPP; even the symbol names
look just about like what I would have expected; stackoverflow said so,
must be true. Just need to get the right symbol defined at build time.

Any suggestions?

AfC
Sydney



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Re: [Haskell-cafe] ifdef based on which OS you're on

That's interesting. But are there standard values for those functions? I'm 
guessing not, seeing a how they're String and not an ADT.

AfC
Sydney

Artyom Kazak artyom.ka...@gmail.com wrote:


You can know the OS and arch without even resorting to CPP; see  
System.Info  which defines `os` and `arch`.


-- 
Andrew Frederik Cowie
Operational Dynamics

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Re: [Haskell-cafe] optimization of recursive functions

2013-02-15 Thread Andrew Polonsky

Thanks for the exhaustive answer.

Andrew


On Wed, Feb 13, 2013 at 2:57 PM, Alp Mestanogullari alpmes...@gmail.comwrote:

 If a difference appears, I believe
 http://blog.johantibell.com/2010/09/static-argument-transformation.htmlwould 
 be involved. Also, the second map function could be inlined by GHC,
 avoiding calling f through a pointer because at the call site, we know
 what 'f' is (this is also mentionned in the blog post by Johan).


 On Wed, Feb 13, 2013 at 9:55 AM, Andrew Polonsky 
 andrew.polon...@gmail.com wrote:

 Hello,

 Is there any difference in efficiency between these two functions, when
 compiled with all optimizations?

 map f [] = []
 map f (a:as) = f a : map f as

 and

 map f x = map' x where
map' [] = []
map' (a:as) = f a : map' as

 Thanks,
 Andrew

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[Haskell-cafe] tls talking to certificate stores (was Re: ...)

On Fri, 2013-02-15 at 15:12 +, Vincent Hanquez wrote:

 Sorry the answer is out of topic

That's ok.

 Windows certificate and macos X certificate are stored in a reliably 
 discoverable place. That openssl provide no way to get to it is a 
 different story and one reason to have tls.

Is talking to the Windows and Mac OS certificate stores something that
you wrote for the tls library [in Haskell]? If so, is it something that
could be ported for other people to use?

[I assume we can just look at tls's source but I'd certainly welcome a
pointer as to where to look]

AfC
Sydney



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Re: [Haskell-cafe] ifdef based on which OS you're on

On Fri, 2013-02-15 at 15:16 +0100, Krzysztof Skrzętnicki wrote:

 See:
 http://www.haskell.org/cabal/users-guide/developing-packages.html#configurations

That link says os():

Tests if the current operating system is name. The argument is
tested against System.Info.os on the target system. There is
unfortunately some disagreement between Haskell implementations
about the standard values of System.Info.os. Cabal canonicalises
it so that in particular os(windows) works on all
implementations. If the canonicalised os names match, this test
evaluates to true, otherwise false. The match is
case-insensitive.

So this approach is back to relying on System.Info.os either way. What
worries me is the Cabal canonicalises it, which seems to indicate that
there are actually many values that show up in 'os' that need to be
regularized. Anyone have any idea if the Cabal library exposes this
somewhere?

AfC
Sydney



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[Haskell-cafe] optimization of recursive functions

2013-02-13 Thread Andrew Polonsky

Hello,

Is there any difference in efficiency between these two functions, when
compiled with all optimizations?

map f [] = []
map f (a:as) = f a : map f as

and

map f x = map' x where
   map' [] = []
   map' (a:as) = f a : map' as

Thanks,
Andrew
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Re: [Haskell-cafe] Mobile app development?

2013-01-22 Thread Andrew Pennebaker

Can we un-deprecate GHC's ability to compile to C code? C may be the best
option to bridge to mobile, as Android, iOS, and Windows RT do support
C/C++ apps.
On Jan 22, 2013 2:14 PM, Dan Choi dhc...@gmail.com wrote:

What about the option of using Haskell's Parsec or AttoParsec to implement
a Haskell-ish language that compiles down not to machine code but to
Objective C or Android Java? Like how CoffeeScript compiles down to
JavaScript.

On Saturday, January 19, 2013 1:58:03 PM UTC-5, Casey Hawthorne wrote:

You would need native compilers for all the platforms and/or virtual
machine technology.

Might be easier to have the browser connect to a Haskell app.

On Sat, Jan 19, 2013 at 10:42 AM, Andrew Pennebaker
andrew.p...@gmail.com wrote:
There are currently very few options, especially free and open source
options, when it comes to developing cross-platform mobile
applications.
It's basically web apps with JavaScript, or C++. If Haskell supported
app
development on Android, iOS, and Windows RT, that alone would bring in
more
developers.

Similarly, there are very few languages for mobile development that
take
advantage of multiple cores and multiple CPUs. Haskell's `parmap` is an
amazing selling point. Can we please prioritize mobile support? I'd
much
rather write everything in ML than PhoneGap.

--
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www.yellosoft.us

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Re: [Haskell-cafe] XCode Dependency for HP on Mac

2013-01-21 Thread Andrew H Bridge

Tom Murphy amindfv at gmail.com writes:

 
 Is there a way to install HP without XCode? Could there be in the
 future? I'm tired of dealing with Apple's constant upgrade
 requirements, registration requirements, etc., and it seems like a
 small function that XCode actually performs in the Haskell development
 toolchain.
 Again, I'm ignorant of the details and I'm sorry if this is ranty, but
 I'd love to hear your reactions.
 
 Thanks!
 Tom
 

Hi,

I know this is an old thread, but it came up on Google when I was 
searching around for an answer to this. So maybe I can still help 
someone.

10.6 users can use this installer on GitHub 
https://github.com/kennethreitz/osx-gcc-installer. It 
installs gcc and a few other bits and pieces (less than a GB to install). 
Then you can install the Haskell Platform. It's worked for me so far! Enjoy!

Thanks,
Andrew


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Re: [Haskell-cafe] XCode Dependency for HP on Mac

2013-01-21 Thread Andrew H Bridge

Mark Lentczner mark.lentczner at gmail.com writes:

 
 As the README at that repository states, For 10.7 and later Apple now
 distributes a Command Line Tools package on the developer site.
 When I build and release the Haskell Platform, I confirm that works 
 when just this package is installed (rather than all of Xcode).

 [Message continues]
 
 - Mark (HP release manager)
 
 
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Hi Mark,

I will keep you updated, the issue is that I refuse to upgrade to 10.7 or later,
many of the brilliant features from Snow Leopard were entirely ruined and
I still see people complaining about having trouble with it on my model of
MacBook.

So for 10.6 users, this 3rd part installer is the only option I could find!

Thanks,
Andrew


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[Haskell-cafe] Mobile app development?

2013-01-19 Thread Andrew Pennebaker

There are currently very few options, especially free and open source
options, when it comes to developing cross-platform mobile applications.
It's basically web apps with JavaScript, or C++. If Haskell supported app
development on Android, iOS, and Windows RT, that alone would bring in more
developers.

Similarly, there are very few languages for mobile development that take
advantage of multiple cores and multiple CPUs. Haskell's `parmap` is an
amazing selling point. Can we please prioritize mobile support? I'd much
rather write everything in ML than PhoneGap.

-- 
Cheers,

Andrew Pennebaker
www.yellosoft.us
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Re: [Haskell-cafe] curl package broken in Windows

2012-11-10 Thread Andrew Pennebaker

Yes, that's a very good point. Did you know that Strawberry Perl includes a
cygwin gcc?

http://strawberryperl.com

Maybe Haskell Platform could do the same.
On Nov 10, 2012 5:28 PM, Stephen Tetley stephen.tet...@gmail.com wrote:

 The only short cut would be to have it in the Platform - otherwise it
 is DIY I'm afraid.

 This is as much Microsoft's fault as Haskell's for not providing a C
 compiler, build tools etc. in the baseline environment.

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Re: [Haskell-cafe] GHC for mobile devices?

2012-11-10 Thread Andrew Pennebaker

I've tried porting GHC to Haiku OS, a Unix-like desktop OS, but the state
of the GHC build system is fairly confusing. The build scripts contain a
Perl script with a bad shebang, and you can't build GHC without already
having a working older version.

If someone can point me to the most recent GHC code that doesn't need
itself to compile, I can work on a Haiku version as practice. I really want
GHC for every possible system.
On Nov 10, 2012 5:49 PM, Kristopher Micinski krismicin...@gmail.com
wrote:

 On Sat, Nov 10, 2012 at 3:50 PM, Casey Basichis caseybasic...@gmail.com
 wrote:
  Hi Kris,
 
  No offense taken, it was an argument that works to shut down constructive
  discussion of how to get Haskell running on mobile, a task which has
  perplexed me for several long days.  I agree most apps are pretty
 terrible,
  at least on iOS though, despite the percentages being wildly off there
 are
  still a few hundred apps that are very well done and thoughtful, none of
  them using Haskell I'm sure.
 

 Yup!  Most of the time apps are merely translated versions of rails
 frontends.  (For better or for worse, I assume that if we were to port
 haskell to work with Android really it would be mostly to appease my
 purity.)

  I'm looking to pass Haskell lists of musical data and return processed
  musical ideas from it (not audio, not realtime).  I was also planning on
  handling a database within Haskell as the information contained would be
  used by the music processing and from what I have read Haskell
 interfaces to
  SQL far more readily than with a C++ orm type solution.  I was planning
 on
  working with Haskells Euterpea as base to build my ideas off of, my I
 might
  end up rolling my own similar library as my aims are a bit different than
  theirs.
 

 I'm not sure I understand completely, but I agree this isn't a bad idea.

  Everything else would be C++, including the interface, audio and dsp
  processing etc.   I already have the C++ stuff running on my phone.  I
 have
  read about the difficulty of getting Haskell working in real world
  scenarios, but as far as I understand my plans for it are fairly well
 suited
  to it.
 

 I don't disagree!

  Since much of the documentation online about Haskell seems to be out of
  date, its tough to get a general feel for whats working.  I see people
  mention that cross-compilation was finished a while back which should
 allow
  for targeting arm but nothing concrete and the website gives conflicting
  info.  I've also considered using GHC to generate C to paste into the
  project but it seems there have been and may be more integrated ways to
 get
  it running.

 I am venturing into my embarrassing lack of knowledge about GHC
 internals here, but how easily would the run time system work on
 Android..?  I had assumed a large part of the effort into getting
 OCaml to work on iPhone went into the runtime system, no?

 If you're (Andrew or anyone) still interested in pursuing this I would
 be interested in helping out, I have some Android internals knowledge
 and would be glad to lend a hand.

 One major thing that seems to be necessary is congealing all the
 (mis/outdated)information into the wiki article on haskell.org.

 kris

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Re: [Haskell-cafe] GHC for mobile devices?

2012-11-10 Thread Andrew Pennebaker

ASM for iOS is possible, so GHC mobile should be possible.

www.shervinemami.info/armAssembly.html#howto
On Nov 10, 2012 5:59 PM, Andrew Pennebaker andrew.penneba...@gmail.com
wrote:

 I've tried porting GHC to Haiku OS, a Unix-like desktop OS, but the state
 of the GHC build system is fairly confusing. The build scripts contain a
 Perl script with a bad shebang, and you can't build GHC without already
 having a working older version.

 If someone can point me to the most recent GHC code that doesn't need
 itself to compile, I can work on a Haiku version as practice. I really want
 GHC for every possible system.
 On Nov 10, 2012 5:49 PM, Kristopher Micinski krismicin...@gmail.com
 wrote:

 On Sat, Nov 10, 2012 at 3:50 PM, Casey Basichis caseybasic...@gmail.com
 wrote:
  Hi Kris,
 
  No offense taken, it was an argument that works to shut down
 constructive
  discussion of how to get Haskell running on mobile, a task which has
  perplexed me for several long days.  I agree most apps are pretty
 terrible,
  at least on iOS though, despite the percentages being wildly off there
 are
  still a few hundred apps that are very well done and thoughtful, none of
  them using Haskell I'm sure.
 

 Yup!  Most of the time apps are merely translated versions of rails
 frontends.  (For better or for worse, I assume that if we were to port
 haskell to work with Android really it would be mostly to appease my
 purity.)

  I'm looking to pass Haskell lists of musical data and return processed
  musical ideas from it (not audio, not realtime).  I was also planning on
  handling a database within Haskell as the information contained would be
  used by the music processing and from what I have read Haskell
 interfaces to
  SQL far more readily than with a C++ orm type solution.  I was planning
 on
  working with Haskells Euterpea as base to build my ideas off of, my I
 might
  end up rolling my own similar library as my aims are a bit different
 than
  theirs.
 

 I'm not sure I understand completely, but I agree this isn't a bad idea.

  Everything else would be C++, including the interface, audio and dsp
  processing etc.   I already have the C++ stuff running on my phone.  I
 have
  read about the difficulty of getting Haskell working in real world
  scenarios, but as far as I understand my plans for it are fairly well
 suited
  to it.
 

 I don't disagree!

  Since much of the documentation online about Haskell seems to be out of
  date, its tough to get a general feel for whats working.  I see people
  mention that cross-compilation was finished a while back which should
 allow
  for targeting arm but nothing concrete and the website gives conflicting
  info.  I've also considered using GHC to generate C to paste into the
  project but it seems there have been and may be more integrated ways to
 get
  it running.

 I am venturing into my embarrassing lack of knowledge about GHC
 internals here, but how easily would the run time system work on
 Android..?  I had assumed a large part of the effort into getting
 OCaml to work on iPhone went into the runtime system, no?

 If you're (Andrew or anyone) still interested in pursuing this I would
 be interested in helping out, I have some Android internals knowledge
 and would be glad to lend a hand.

 One major thing that seems to be necessary is congealing all the
 (mis/outdated)information into the wiki article on haskell.org.

 kris


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[Haskell-cafe] curl package broken in Windows

When I do cabal install curl in Windows, a missing cygwin dll message
pops up, and packages that depend on curl, like shpider, fail to install.

Specs:

* cabal-install 0.14.0
* Cabal 1.14.0
* GHC 7.4.2
* Haskell Platform 2012
* Windows 7 Proffesional x64

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[Haskell-cafe] GHC for mobile devices?

I'd love to use Haskell directly for making mobiles apps. How can we make
this happen, porting GHC to Android, iOS, and Windows Phone?

-- 
Cheers,

Andrew Pennebaker
www.yellosoft.us
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[Haskell-cafe] Motion to unify all the string data types

Frequently when I'm coding in Haskell, the crux of my problem is converting
between all the stupid string formats.

You've got String, ByteString, Lazy ByteString, Text, [Word], and on and
on... I have to constantly lookup how to convert between them, and the
overloaded strings GHC directive doesn't work, and sometimes
ByteString.unpack doesn't work, because it expects [Word8], not [Char].
AAAH!!!

Haskell is a wonderful playground for experimentation. I've started to
notice that many Hackage libraries are simply instances of typeclasses
designed a while ago, and their underlying implementations are free to play
around with various optimizations... But they ideally all expose the same
interface through typeclasses.

Can we do the same with String? Can we pick a good compromise of lazy vs
strict, flexible vs fast, and all use the same data structure? My vote is
for type String = [Char], but I'm willing to switch to another data
structure, just as long as it's consistently used.

-- 
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Re: [Haskell-cafe] GHC for mobile devices?

Awesome! Jeffrey Scofield has ported OCaml to
iOShttp://psellos.com/ocaml/compile-to-iossim.html,
so there's also experience there.

On Fri, Nov 9, 2012 at 11:46 PM, Kristopher Micinski krismicin...@gmail.com
 wrote:

 If you have interest in doing this, I have quite a bit of experience
 in Android hacking at the system level and above and would be glad to
 talk about what might need to happen.  (Though I don't know the GHC
 internals / toolchain so well.)

 One potential choice is Scala, though from my limited experience
 that's a very rough imitation of the uses for Haskell.  (Though,
 obviously it works mostly out of the box because of the JVM compiler
 target..)

 http://www.haskell.org/haskellwiki/Android

 I've been writing up some thoughts on the Android activity lifecycle
 already interpreted with respect to FP, apps are quite functional
 already for a variety of reasons.

 kris

 On Fri, Nov 9, 2012 at 8:51 PM, Andrew Pennebaker
 andrew.penneba...@gmail.com wrote:
  I'd love to use Haskell directly for making mobiles apps. How can we make
  this happen, porting GHC to Android, iOS, and Windows Phone?
 
  --
  Cheers,
 
  Andrew Pennebaker
  www.yellosoft.us
 
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[Haskell-cafe] How do I specify language literals in hsparql?

2012-10-21 Thread Andrew Pennebaker

If the raw SPARQL is rdfs:label D (programming language)@en, what would
the hsparql http://hackage.haskell.org/package/hsparql syntax be?

The docshttps://github.com/robstewart57/hsparql/blob/master/tests/DBPedia.hs
don't
include any language literal examples.

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[Haskell-cafe] Tutorial: Haskell for the Evil Genius

I've gotten mixed feedback from Reddit for my tutorial. It provides an
overview of how functional and declarative programming in Haskell empower
baddies, increasing the accuracy and efficiency of their atomic
superweapons. What do you guys think of my tutorial, Haskell for the Evil
Genius http://www.yellosoft.us/evilgenius/?

Cheers,

Andrew Pennebaker
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Re: [Haskell-cafe] Tutorial: Haskell for the Evil Genius

A summary of the changes I've included so far:


 Under Declarative, you aren't creating a named expression, 2 + 2, really.
 You are redefining (+).


Noted and reflected in the new version.


 Under Lazy, your example of binding fib 30 is not a good example of
 memoization. With memoization you typically call the underlying computation
 the first time, and memoize it for repeated retrieval later, not hardwire
 in
 values at compile time. Here you never ever call the real fib at all. On
 top
 of everything else, it'd be too easy to introduce a typo into one of your
 hardwired constant values.


Noted and reflected in the new version. After several comments to this
effect, I do not want to misrepresent memoization in the tutorial.
Sometimes it is useful to be slightly inaccurate in a tutorial in order to
help bridge the gap between someone with no experience in a something vs
the wealth of knowledge and complexity in the thing itself. This is not one
of those times, and fortunately, fixing the misrepresentation in my
tutorial is as easy as removing the hardcoded call.

One thing I want to double check is that Haskell does, in fact,
automatically memoize all pure function calls. Is this true?

I would still like to provide a performance comparison of the Fibonacci
code with and without memoization, for readers who enjoy numerical
evidence, using the Unix time command, but I don't know how to turn
memoization off. I guess I would have to reimplement the algorithm in a way
that can't make use of memoization. Any suggestions?

Under Infinite, you should use sieve (n:ns) pattern matching instead of
 calling head.


Thank you! I try to make use of Haskell pattern matching wherever I can.
Since I needed to refer to the whole list, as well as the head and tail, I
originally used head instead of pattern matching. Noted and reflected in
the new version.


 Under Type-Safe
 Subtle distinction, but returning () is not the same as returning nothing
 at all.


True. Noted and reflected in the new version. What's the Haskell name for
() again? I fear explaining the exact type information of IO () may be too
much for a brief introduction to Haskell to cover.


 s/ommitted/omitted/


Noted and reflected in the new version.


 You've got an unusual indentation scheme. Consider adopting a more standard
 one for your tutorial.


I'm in the camp of hard tabs rather than soft tabs, and that preference is
probably responsible for much of the difference in indentation scheme.
Unfortunately, HTML is terrible at representing hard tabs in PRE code
with a custom width preference; they all come out looking like some idiot
pressed space bar eight times. I could use JavaScript to remedy this, but
for now, I like to directly copy and paste my working code from .HS files
into PRE tags just in case.

If tabs are *not* the issue, then maybe I'm not indenting far enough to the
right for some tastes? Or maybe it's my tendency to put where on its own
line, something a Perl obfuscater would detest. I dunno. If someone would
suggest a more idiomatic indentation scheme for my code so that I know
exactly what is different, I can take a look.


 In general, monotonically decreasing is not sufficient to prove you will
 hit
 a base case. For example, decreasing by 5 would still be monotonically
 decreasing, and could jump right over your base cases.
 (Not arguing that the code is incorrect, but rather than your explanation
 is
 a little misleading/incomplete.)


Understood. Noted and reflected in the new version.

Incidentally, when will Nat be available in Haskell? The Fibonacci
algorithm is designed to work only over natural numbers, and the best way
to express this in the type system is with Nat. But this type doesn't seem
available out-of-the-box for Haskell users. Unless I'm using my Haskell
Platform (GHC 7.0.3) is slightly outdated. Eh?


 Again, further confusion about what memoization really is.


 Under Records

 Functions are already defined by their data structures; they are already
 semantically bundled... doesn't seem to make sense.


Noted and reflected... I'm trying to convey to an audience largely composed
of Java and C++ fanatics how Haskell records are much better than OOP, how
GADTs are more intuitive, robust, ... OOP doesn't even compare! That's what
I'm trying to get across in that bit. And it's hard to do this in just a
few sentences, especially when the reader isn't even familiar with GADTs in
the first place.

... acts on the specific constructor, blasting fools, murdering crowds...
 makes it sound like fireOn actually has side effects.


A truly fair point. Would you like to contribute a monad for blowing up the
moon?

Another comment:


 As a declarative language, Haskell manipulates expressions, eventually
 reducing expressions to values.


 Huh? In what sense do declarative languages manipulate expressions? Sounds
 like a classic syntax/semantics confusion, especially when interpreters
 and/or lazy evaluation

Re: [Haskell-cafe] Tutorial: Haskell for the Evil Genius


 Experiment #4:

 fib :: Int - Int
 fib n = mem !! n

 mem :: [Int]
 mem = map aux [0..]
 -- remark: even [Int] is not a very efficient data structure for this

 aux 0 = 0
 aux 1 = 1
 aux n = mem!!(n-1) + mem!!(n-2)

 main :: IO ()
 main = mapM_ (print . fib) (replicate 10 30)

 Question: How fast is this compared to #1? Why?


Final remark: Evil geniuses should use the scientific method, not the
 opinionative method.


Noted and reflected in the new version.

Thank you for taking the time to write out a detailed, practical analysis
of the question. Yes, I should assume less and test more. I tried
these outhttps://github.com/mcandre/mcandre/tree/master/haskell/memfibas
requested, and came up with results demonstrating that Haskell, does
not, as I mistakenly interpreted, automatically memoize all function calls.
Which makes sense, otherwise memory would quickly run out.

I found some useful reference code on the Haskell Wiki and constructed my
own memoized Fibonacci function using the MemoTrie library, which,
fortunately, is builtin with Haskell Platform and therefore does not
require the tutorial reader to install additional code.

The new version of the tutorial includes an ordinary recursive Fibonacci
function (fib1.hs), and the same code but renamed to fib', memoized using
the memo function from the MemoTrie library (fib2.hs), and exposed as fib.
Unix time information provides real numbers for comparison: The memoized
version is clearly much faster.

I rewrote the section, deleting the part that stated memoization was
automatic, and added text describing how Haskell makes memoization easy.
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Re: [Haskell-cafe] Tutorial: Haskell for the Evil Genius


 But, Haskell records aren't better than OOP.

 I am not trying to be controversial here -- Haskell records would
 naturally implement prototype-based OOP, like JavaScript uses, if they
 (Haskell records) weren't so useless.  This is basically why lenses were
 designed (i.e., to make consistent syntax for getters and setters)


Hey, I don't want the tutorial to be controversial either, especially since
my word choice of words like better are highly subjective. I find
it extraordinarily empowering that Haskell's type system allows programmers
to use a wide variety of programming paradigms: functional, declarative,
imperative, lazy, eager, parallel, quantum, matrix, CUDA, multithreaded,
distributed, logical, object oriented...

When I describe Haskell's type system as better than OOP, what I mean is
this: You can code OOP in Haskell, because the type system can adapt to
that. But it's much harder to go the other way, trying to code GADTs in
Java/C++. In order to get the effect, you'll have to code something as
complex as Scala, at which point you might as well just use Haskell (unless
you really really really need the JVM for compatibility). It's the same
with Lisp or JavaScript or Smalltalk or Ruby: Allowing the programmer to
roll his own paradigm, such as OOP, is more powerful than offering only
that paradigm. More to the point, the monad system enables all of this, and
I'm not sure how to reword this tutorial to reflect that; monads themselves
are generally treated as an advanced lesson, and this one tries to hit the
ground running.

Does anyone know of a brief introductory Haskell tutorial that engages
monads? LYAH covers monads, but it does so after a few chapters of simpler,
pure function Haskell coding. I know of some brief tutorials for monads
that explain them in a variety of creative ways, but they all assume the
reader is at least somewhat familiar with Haskell.
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Re: [Haskell-cafe] Tutorial: Haskell for the Evil Genius


 Everyone in the Haskell cafe probably has a secret dream to give the
 best five minute monad talk.  Challenge: get someone to have a
 competition at one of the conferences where students all give their
 best five minute monad talk and try to find the most comprehensible
 one!


Haha, maybe that's why I'm writing.

Agree on all points, not just this quotation.

Yeah, IO and Maybe are the first monads most new Haskell programmers
encounter.  Perhaps a tour of RVars or the accelerate library would give a
better impression. I bet a lot of students get the concept of pure
functional programming, and if you shock them with: So how would you
implement a PRNG?, they would understand the role monads play.

Given that Maybe and Either don't modify state, nor do they communicate
with outside interfaces, nor do they specify computation ordering, I don't
understand why they're implemented as monads. Why not a primitive typeclass
or even datatype declaration?
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Re: [Haskell-cafe] Tutorial: Haskell for the Evil Genius


 Challenge: get someone to have a competition at one of the conferences
 where students all give their
 best five minute monad talk and try to find the most comprehensible one!


Challenge accepted http://www.yellosoft.us/5min/.
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[Haskell-cafe] How do I generate random numbers using random-fu, with platform-agnostic code?

2012-09-13 Thread Andrew Pennebaker

I can't figure out how to use Data.Random.Source.IO to generate random
numbers in a multiplatform way.

I can generate random numbers in Unix using Data.Random.Source.DevRandom,
and there is an example in the GitHub documentation for Windows using
Data.Random.Source.MWC, but there is no example code for using
Data.Random.Source.IO.

Cheers,

Andrew Pennebaker
www.yellosoft.us
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Re: [Haskell-cafe] createProcess running non-existent programs

2012-08-13 Thread Andrew Cowie

On Sun, 2012-08-12 at 23:18 -0700, Evan Laforge wrote:
 Yes, I ran into the same thing a while back.  The problem is that the
 subprocess has already been forked off before it runs exec() and finds
 out the file doesn't exist.

Given how astonishingly common it is to pass an invalid executable name
and/or path, wouldn't it be worth doing a quick probe to see if the file
exists before createProcess actually forks?

[It's not like the effort the OS is going to do for the stat is going to
be thrown away; whether that call pulls it up off of disk or the one
after the fork that exec will do doesn't matter]

AfC
Sydney



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Re: [Haskell-cafe] What Haskell Records Need

2012-08-02 Thread Andrew Butterfield


On 2 Aug 2012, at 09:25, Erik Hesselink wrote:

 Isn't this exactly the problem solved by all the lens packages?
 Current popular ones are fclabels [0] and data-lens [1].
 
 [0] http://hackage.haskell.org/package/fclabels
 [1] http://hackage.haskell.org/package/data-lens

Not sure what all of these do, but I have a simple solution I use
in my work:
 
 Take the following types from a contrived
 example.
 
 type Salary = Integer
 
 data Job = Job
 { title  :: String
 , salary :: Salary
 }

Rather than setTitle :: String - Job - Job  we lift the first argument
and define

setfTitle  :: (String - String) - Job - Job
setfTitle f jobrec = jobrec{ title = f $ title jobrec }

then setTitle = setfTitle . const

This is all just boilerplate, so we continue

setfSalary :: (Salary - Salary) - Job - Job
setfSalary f jobrec = jobrec{ salary = f $ salary jobrec }

 
 data Person = Person
 { name :: String
 , job  :: Job
 }
 


setfName :: (String - String) - Person - Person
setfName f prec = prec{ name = f $ name prec }

setfJob :: (Job - Job) - Person - Person
setfJob f prec = prec{ job = f $ job prec }

Now we can use function composition to do two levels

setfTitleInPerson :: (String - String) - Person - Person
setfTitleInPerson = setfJob . setfTitle

setTitleInPerson :: String - Person - Person
setTitleInPerson = setfTitleInPerson . const

Simple function composition works to put these together...


I was frustrated by this problem a while back, and decided to approach it 
formally
(I write literate Haskell/LateX documents), and went to work, doing the math
with the intention of writing a suitable combinator, until I discovered I didn't
need one  lifting from  X - R - R   to (X - X) - R - R gave me all I 
needed...



 Since I've used record syntax, I get
 getter/accessor functions (title, salary,
 name, job) for free. Now suppose I want to
 create an aggregate getter function: return
 the salary of a given person. Piece of cake,
 it's just function composition
 
 getSalary :: Person - Salary
 getSalary = salary . job
 
 Done! Now suppose I want to write a
 setter/mutator function for the same nested
 field
 
 setSalaryMessy :: Salary - Person - Person
 setSalaryMessy newSalary person =
 person {
  job = (job person) {
salary = newSalary
  }
 }
 
 Ouch! And that's not even very deeply nested.
 Imagine 4 or 5 levels deep. It really makes
 Haskell feel clunky next to `a.b.c.d = val`
 that you see in other languages. Of course
 immutability means that the semantics of
 Haskell are quite different (we're creating
 new values here, not updating old ones) but
 it's still common to model change using these
 kinds of updates.
 
 What if along with the free getters that
 the compiler generates when we use record
 syntax, we also got semantic editor
 combinator (SEC) functions[0] that could be
 used as follows?
 
 setSalary newSalary = job' $ salary' (const newSalary)
 
 giveRaise amount = job' $ salary' (+amount)
 
 givePercentRaise percent = job' $ salary' (*(1+percent))
 
 For each field x, the compiler generates a
 function x' (the tic is mnemonic for change).
 These little functions aren't hard to write,
 but they're classic boilerplate.
 
 job' :: (Job - Job) - Person - Person
 job' f person = person {job = f $ job person}
 
 salary' :: (Salary - Salary) - Job - Job
 salary' f job = job { salary = f $ salary job}
 
 These type of utility functions are a dream
 when working with any reference type or
 State Monad.
 
 modify $ givePercentRaise 0.25
 
 The compiler could also generate polymorphic
 SEC functions for polymorphic fields.
 Further, the compiler could disallow using
 old-style update syntax for fields whose SEC
 update function is not in scope, giving us
 fine-grained control over access and update.
 On the other hand we currently have to create
 new functions to achieve this (exporting the
 getter means exporting the ability to update
 as well, currently).
 
 Of course this doesn't address the
 namespacing issues with records, but it is
 likely nicely orthogonal to other proposals
 which do.
 
 Also note that there's a package on hackage [1]
 that will generate SEC functions using TH.
 It's nice, but I prefer the style of field
 names used above for updaters (field' vs
 editField).
 
 Let me know what you think. I'll write up an
 official proposal if there's a bit of
 general interest around this.
 
 Thanks for reading,
 
 --Jonathan
 
 [0] - http://conal.net/blog/posts/semantic-editor-combinators
 [1] -
 http://hackage.haskell.org/packages/archive/sec/0.0.1/doc/html/Data-SemanticEditors.html
 
 
 
 
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Andrew Butterfield

Re: [Haskell-cafe] What Haskell Records Need

2012-08-02 Thread Andrew Butterfield

Ah yes - the joy of Haskell

It so easy to roll your own, rather than search to find someone else's
(better/more elegant) solution...   :-)


On 2 Aug 2012, at 11:41, Erik Hesselink wrote:

 On Thu, Aug 2, 2012 at 12:30 PM, Andrew Butterfield
 andrew.butterfi...@scss.tcd.ie wrote:
 
 On 2 Aug 2012, at 09:25, Erik Hesselink wrote:
 
 Isn't this exactly the problem solved by all the lens packages?
 Current popular ones are fclabels [0] and data-lens [1].
 
 [0] http://hackage.haskell.org/package/fclabels
 [1] http://hackage.haskell.org/package/data-lens
 
 Not sure what all of these do, but I have a simple solution I use
 in my work:
 
 They do exactly that. They create 'lenses' which are
 getters/setters/modifiers combined, and allow you to compose these to
 get/set/modify deep inside nested data types. Look at the examples in
 the fclabels documentation [2] for more details.
 
 [2] 
 http://hackage.haskell.org/packages/archive/fclabels/1.1.4/doc/html/Data-Label.html


Andrew Butterfield Tel: +353-1-896-2517 Fax: +353-1-677-2204
Lero@TCD, Head of Foundations  Methods Research Group
Director of Teaching and Learning - Undergraduate,
School of Computer Science and Statistics,
Room G.39, O'Reilly Institute, Trinity College, University of Dublin
  http://www.scss.tcd.ie/Andrew.Butterfield/



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Re: [Haskell-cafe] ANN: Portackage - a hackage portal

2012-06-15 Thread Andrew Seniuk

Now all packages, including those without exposed modules, are
included. Also, I've attempted to parse the author lists into JSON
arrays. Due to the free format of many fields in the .cabal package
descriptions, including author list, there are many exceptional cases
where they are ill-parsed, but at least the JSON file is well-formed
and validates at jsonlint.com.

Once more:

JSON Schema:
http://www.fremissant.net/portackage/packages.schema.json.txt

Hopefully compressed JSON data:
http://www.fremissant.net/portackage/packages.php

Raw JSON data in case the compressed doesn't work:
http://www.fremissant.net/portackage/packages.json

The hackage data updated as of yesterday (June 14). Will work on daily
incremental updates from Hackage RSS feed soon.

-Andrew

On Thu, Jun 14, 2012 at 7:05 PM, Andrew Seniuk ras...@gmail.com wrote:
 I discovered http://jsonlint.com/ and got it to validate. :)

 On Thu, Jun 14, 2012 at 6:18 PM, Andrew Seniuk ras...@gmail.com wrote:
 Hi ___,

 Thank you for your suggestion to provide JSON, which seconds Derek's
 earlier suggestion. I have anonymised your name since you wrote to me
 but didn't CC the list. :)

 As much as I wish the web interface was up to snuff, it is really too
 slow. While I continue to try to resolve that, there is something like
 a JSON feed available now. I'm new to these things and may be doing it
 wrong. Any advice would be appreciated, either in accelerating the web
 interface or in providing the JSON. I have no idea whether it parses
 or not.

 JSON Schema:
 http://www.fremissant.net/portackage/packages.schema.json.txt

 Hopefully compressed JSON data:
 http://www.fremissant.net/portackage/packages.php

 Raw JSON data in case the compressed doesn't work:
 http://www.fremissant.net/portackage/packages.json

 The hackage data updated as of today (June 14).

 For now this is only the packages which expose modules (i.e. not
 including binary packages). No particular reason, I just ran out of
 time this afternoon and thought I'd post what I've got.

 The fields present in the JSON are those available on the HTML table
 version. There are several dozen other fields which come up more or
 less infrequently in the Hackage packages, and they could all be
 included. The complete list of modules is included (rather than the
 summary versions used in the HTML table version).

 A next step would be for the server to incrementally update the JSON
 data based on the Hackage RSS feed.

 Kind Regards,
 Andrew

 On Wed, Jun 13, 2012 at 7:58 AM, ___ wrote:
 Hi Andrew

 Portackage is a great site for browsing packages, but it's really
 really slow for filtering per column. What about offering an
 additional non-javascript version of the pages -- searching with plain
 text in a browser works quite well.

 On 4/30/12, Andrew Seniuk ras...@gmail.com wrote:
 Oops, the three links in summary are:

 module tree: http://fremissant.net/portackage/modules.php
 library packages: http://fremissant.net/portackage/portackage.php
 other packages: http://fremissant.net/portackage/binary.php

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Re: [Haskell-cafe] ANN: Portackage - a hackage portal

2012-06-14 Thread Andrew Seniuk

Hi ___,

Thank you for your suggestion to provide JSON, which seconds Derek's
earlier suggestion. I have anonymised your name since you wrote to me
but didn't CC the list. :)

As much as I wish the web interface was up to snuff, it is really too
slow. While I continue to try to resolve that, there is something like
a JSON feed available now. I'm new to these things and may be doing it
wrong. Any advice would be appreciated, either in accelerating the web
interface or in providing the JSON. I have no idea whether it parses
or not.

JSON Schema:
http://www.fremissant.net/portackage/packages.schema.json.txt

Hopefully compressed JSON data:
http://www.fremissant.net/portackage/packages.php

Raw JSON data in case the compressed doesn't work:
http://www.fremissant.net/portackage/packages.json

The hackage data updated as of today (June 14).

For now this is only the packages which expose modules (i.e. not
including binary packages). No particular reason, I just ran out of
time this afternoon and thought I'd post what I've got.

The fields present in the JSON are those available on the HTML table
version. There are several dozen other fields which come up more or
less infrequently in the Hackage packages, and they could all be
included. The complete list of modules is included (rather than the
summary versions used in the HTML table version).

A next step would be for the server to incrementally update the JSON
data based on the Hackage RSS feed.

Kind Regards,
Andrew

On Wed, Jun 13, 2012 at 7:58 AM, ___ wrote:
 Hi Andrew

 Portackage is a great site for browsing packages, but it's really
 really slow for filtering per column. What about offering an
 additional non-javascript version of the pages -- searching with plain
 text in a browser works quite well.

 On 4/30/12, Andrew Seniuk ras...@gmail.com wrote:
 Oops, the three links in summary are:

 module tree: http://fremissant.net/portackage/modules.php
 library packages: http://fremissant.net/portackage/portackage.php
 other packages: http://fremissant.net/portackage/binary.php

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 Haskell-Cafe@haskell.org
 http://www.haskell.org/mailman/listinfo/haskell-cafe



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Re: [Haskell-cafe] ANN: Portackage - a hackage portal

2012-06-14 Thread Andrew Seniuk

I discovered http://jsonlint.com/ and got it to validate. :)

On Thu, Jun 14, 2012 at 6:18 PM, Andrew Seniuk ras...@gmail.com wrote:
 Hi ___,

 Thank you for your suggestion to provide JSON, which seconds Derek's
 earlier suggestion. I have anonymised your name since you wrote to me
 but didn't CC the list. :)

 As much as I wish the web interface was up to snuff, it is really too
 slow. While I continue to try to resolve that, there is something like
 a JSON feed available now. I'm new to these things and may be doing it
 wrong. Any advice would be appreciated, either in accelerating the web
 interface or in providing the JSON. I have no idea whether it parses
 or not.

 JSON Schema:
 http://www.fremissant.net/portackage/packages.schema.json.txt

 Hopefully compressed JSON data:
 http://www.fremissant.net/portackage/packages.php

 Raw JSON data in case the compressed doesn't work:
 http://www.fremissant.net/portackage/packages.json

 The hackage data updated as of today (June 14).

 For now this is only the packages which expose modules (i.e. not
 including binary packages). No particular reason, I just ran out of
 time this afternoon and thought I'd post what I've got.

 The fields present in the JSON are those available on the HTML table
 version. There are several dozen other fields which come up more or
 less infrequently in the Hackage packages, and they could all be
 included. The complete list of modules is included (rather than the
 summary versions used in the HTML table version).

 A next step would be for the server to incrementally update the JSON
 data based on the Hackage RSS feed.

 Kind Regards,
 Andrew

 On Wed, Jun 13, 2012 at 7:58 AM, ___ wrote:
 Hi Andrew

 Portackage is a great site for browsing packages, but it's really
 really slow for filtering per column. What about offering an
 additional non-javascript version of the pages -- searching with plain
 text in a browser works quite well.

 On 4/30/12, Andrew Seniuk ras...@gmail.com wrote:
 Oops, the three links in summary are:

 module tree: http://fremissant.net/portackage/modules.php
 library packages: http://fremissant.net/portackage/portackage.php
 other packages: http://fremissant.net/portackage/binary.php

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 http://www.haskell.org/mailman/listinfo/haskell-cafe



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Re: [Haskell-cafe] High memory usage with 1.4 Million records?

2012-06-08 Thread Andrew Myers

Thanks for the responses everyone, I'll try them out and see what happens :)
Andrew

On Fri, Jun 8, 2012 at 4:40 PM, Johan Tibell johan.tib...@gmail.com wrote:

 Hi Andrew,

 On Thu, Jun 7, 2012 at 5:39 PM, Andrew Myers asm...@gmail.com wrote:
  Hi Cafe,
  I'm working on inspecting some data that I'm trying to represent as
 records
  in Haskell and seeing about twice the memory footprint than I was
  expecting.  I've got roughly 1.4 million records in a CSV file (400M on
  disk) that I parse in using bytestring-csv.  bytestring-csv returns a
  [[ByteString]] (wrapped in `type`s) which I then convert into a list of
  records that have the following structure:
 
  3  Int
  1 Text Length 3
  1 Text Length 11
  12 Float
  1 UTCTime
 
  All fields are marked strict and have {-# UNPACK #-} pragmas (I'm
 guessing
  that doesn't do anything for non primitives).  (Side note, is there a
 way to
  check if things are actually being unpacked?)

 GHC used to complain when you use UNPACK with something that can't be
 unpacked, but that warning seems to have been (accidentally) removed
 in 7.4.1.

 The rule for unpacking is:

 * all product types (i.e. types with only one constructor) can be
 unpacked. This includes Int, Char, Double, etc and tuples or records
 their-of.
 * sum types (i.e. data types with more than one constructor) and
 polymorphic fields can't be unpacked.

  My back of the napkin memory estimates based on the assumption that
 nothing
  is being unpacked (and my very spotty understanding of Haskell data
  structures):
 
  Platform: 64 Bit Linux
  #  Type (Sizeof type (occasionally a guess))
 
  3 * Int (8)
  14 * Char (4) -- Text is some kind of bytestring but I'm guessing it
 can't
  be worse than the same number of Char?
  12  * Float (4)
  18 * sizeOf (ptr) (8)
  UTC:  -- From what I can gather through :info in ghci
  4 * (ptr) (8)
  2 * Integer (16) -- Shouldn't be overly large, times are within 2012

 All fields in a constructor are word aligned. This means that all
 primitive types take 8 bytes on a 64-bit platform, including Char and
 Float. You might find the following blog posts by me useful in
 computing the size of data structures:


 http://blog.johantibell.com/2011/06/memory-footprints-of-some-common-data.html
 http://blog.johantibell.com/2011/06/computing-size-of-hashmap.html
 http://blog.johantibell.com/2011/11/slides-from-my-guest-lecture-at.html

 Here's some more on the topic:


 http://stackoverflow.com/questions/3254758/memory-footprint-of-haskell-data-types

 http://stackoverflow.com/questions/657/how-to-find-out-ghcs-memory-representations-of-data-types

  I've written a small driver test program that just parses the CSV, finds
 the
  minimum value for a couple of the Float fields, and exits.  In the
 process
  monitor the memory usage is 6.9G before the program exits.  I've tried
  profiling with +RTS -hc but it ran for 3 hours without finishing, it
  normally finishes within 4 minutes.  Anyone have any ideas for me?
 Things
  to try?
  Thanks,
  Andrew

 You could try to use a 32-bit GHC, which would use about half the
 memory. You're at the limit of the size of data that you can
 comfortably fit in memory on a normal desktop machine, so it might be
 time to consider a streaming approach.

 -- Johan

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[Haskell-cafe] High memory usage with 1.4 Million records?

2012-06-07 Thread Andrew Myers

Hi Cafe,
I'm working on inspecting some data that I'm trying to represent as records
in Haskell and seeing about twice the memory footprint than I was
expecting.  I've got roughly 1.4 million records in a CSV file (400M on
disk) that I parse in using bytestring-csv.  bytestring-csv returns a
[[ByteString]] (wrapped in `type`s) which I then convert into a list of
records that have the following structure:

 3  Int
 1 Text Length 3
 1 Text Length 11
 12 Float
 1 UTCTime

All fields are marked strict and have {-# UNPACK #-} pragmas (I'm guessing
that doesn't do anything for non primitives).  (Side note, is there a way
to check if things are actually being unpacked?)

My back of the napkin memory estimates based on the assumption that nothing
is being unpacked (and my very spotty understanding of Haskell data
structures):

Platform: 64 Bit Linux
#  Type (Sizeof type (occasionally a guess))

3 * Int (8)
14 * Char (4) -- Text is some kind of bytestring but I'm guessing it can't
be worse than the same number of Char?
12  * Float (4)
18 * sizeOf (ptr) (8)
UTC:  -- From what I can gather through :info in ghci
4 * (ptr) (8)
2 * Integer (16) -- Shouldn't be overly large, times are within 2012

List: (Pointer to element and next cons cell)
1408113 * 8 * 2

=
2513G + 21.5M
So even if the original bytestring file is being kept entirely in memory
somehow that's not more than 3G.

I've written a small driver test program that just parses the CSV, finds
the minimum value for a couple of the Float fields, and exits.  In the
process monitor the memory usage is 6.9G before the program exits.  I've
tried profiling with +RTS -hc but it ran for 3 hours without finishing, it
normally finishes within 4 minutes.  Anyone have any ideas for me?  Things
to try?
Thanks,
Andrew
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Re: [Haskell-cafe] Haskell source AST zipper with state

2012-05-03 Thread Andrew Seniuk

On Thu, May 3, 2012 at 2:22 AM, Niklas Broberg niklas.brob...@gmail.com wrote:
 On Thu, May 3, 2012 at 2:52 AM, Andrew Seniuk ras...@gmail.com wrote:

 Note that the Annotated version of the HSE parser/AST will probably
 not provide enough generality for the sorts of attributes you want to 
 store...

 I do hope you're wrong on that! The annotations are fully general (and have
 been all along), so you can store whatever you like there(*). They are
 *used* for source locations by the parser, but that's just one possibility.

 (*) The only requirement is that you need to store values of the same type
 throughout the syntax tree - but Either or Maybe should do the trick there.

Sorry Niklas! Thanks for the mild correction. (Wish I'd understood
that when trying to compute the semilattice joins I needed.)

Any recommendations for a zipper (or other traversal) library for use with HSE?

Andrew

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Re: [Haskell-cafe] Haskell source AST zipper with state

2012-05-02 Thread Andrew Seniuk

On Wed, May 2, 2012 at 7:20 PM, Tony Morris tonymor...@gmail.com wrote:
 Is there a library to traverse a source AST keeping state?

Hi Tony, I was able to do this [1] using haskell-src-exts and a state
monad.  AST traversal is possible due to HSE deriving instances for
Data in all its datatype declarations, but the traversals were of a
generic variety, rather than zippers.  I read Scrap Your Zippers [2]
and looked at various other generic zipper libs, but in the end I
managed without zippers.  Note that most zipper libs require instance
declarations for all the syntax datatypes -- Scrap Your Zippers only
requires the Data instances that HSE comes with, not sure why I was
unable to use it, probably just inexperience.

Note that the Annotated version of the HSE parser/AST will probably
not provide enough
 generality for the sorts of attributes you want to store (it's for
source locations, unless something changed in the most recent
release).

Best of luck, and I'll be interested to hear other responses!

-Andrew

[1] http://hackage.haskell.org/freesect (in particular FreeSect*.hs)
[2] https://www.cs.indiana.edu/~adamsmd/papers/scrap_your_zippers/

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Re: [Haskell-cafe] [Haskell] ANN: Portackage - a hackage portal

2012-04-30 Thread Andrew Seniuk

First let me mention, there is now a complete modules tree with API
links (in a very preliminary state), at
http://fremissant.net/portackage/modules.php and the package view is
still http://fremissant.net/portackage

On Mon, Apr 30, 2012 at 11:35 AM, Simon Michael si...@joyful.com wrote:
 Great work! Thanks.

 Does it include only packages without executables ? Eg I see
 hledger-lib but not the hledger or gist packages. It would be nice
 to have all of hackage there.

Simon, thank you. And, yes, as a temporary measure, I elided the
packages that expose no modules, to try to tame the slowness a bit. I
could provide them on a similar, separate page, until figure out some
optimisations.

Derek, if you're reading, sorry if I seemed defensive there before. :)

Okay, this bagel is screaming Eat Me!!...

Kind Reg'ds,
Andrew

On Mon, Apr 30, 2012 at 11:35 AM, Simon Michael si...@joyful.com wrote:
 Great work! Thanks.

 Does it include only packages without executables ? Eg I see hledger-lib but
 not the hledger or gist packages. It would be nice to have all of hackage
 there.

 Best - Simon


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Re: [Haskell-cafe] [Haskell] ANN: Portackage - a hackage portal

2012-04-30 Thread Andrew Seniuk

...and the binary packages (those exposing no modules) are now up at
http://fremissant.net/portackage/binary.php

Not nice to have them in a separate table, but for now that's the case. :(

So the three links in summary:

module tree: http://fremissant.net/portackage/modules.php
library packages: http://fremissant.net/portackage/binary.php
other packages: http://fremissant.net/portackage/portackage.php

On Mon, Apr 30, 2012 at 1:42 PM, Andrew Seniuk ras...@gmail.com wrote:
 First let me mention, there is now a complete modules tree with API
 links (in a very preliminary state), at
 http://fremissant.net/portackage/modules.php and the package view is
 still http://fremissant.net/portackage

 On Mon, Apr 30, 2012 at 11:35 AM, Simon Michael si...@joyful.com wrote:
 Great work! Thanks.

 Does it include only packages without executables ? Eg I see
 hledger-lib but not the hledger or gist packages. It would be nice
 to have all of hackage there.

 Simon, thank you. And, yes, as a temporary measure, I elided the
 packages that expose no modules, to try to tame the slowness a bit. I
 could provide them on a similar, separate page, until figure out some
 optimisations.

 Derek, if you're reading, sorry if I seemed defensive there before. :)

 Okay, this bagel is screaming Eat Me!!...

 Kind Reg'ds,
 Andrew

 On Mon, Apr 30, 2012 at 11:35 AM, Simon Michael si...@joyful.com wrote:
 Great work! Thanks.

 Does it include only packages without executables ? Eg I see hledger-lib but
 not the hledger or gist packages. It would be nice to have all of hackage
 there.

 Best - Simon


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Re: [Haskell-cafe] [Haskell] ANN: Portackage - a hackage portal

2012-04-30 Thread Andrew Seniuk

Oops, the three links in summary are:

module tree: http://fremissant.net/portackage/modules.php
library packages: http://fremissant.net/portackage/portackage.php
other packages: http://fremissant.net/portackage/binary.php

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Re: [Haskell-cafe] [Haskell] ANN: Portackage - a hackage portal

2012-04-28 Thread Andrew Seniuk

 On Apr 27, 2012 6:18 PM, Andrew Seniuk ras...@gmail.com wrote:
 Oh, the idea wasn't that you would make the app, but that by providing a web
 service interface you would make it easier for me or anyone else to make an
 app or other alternative interface.  It would also reduce bandwidth usage
 over screen scraping.

Yes, well as I mentioned in the part of my response you didn't quote,
I agree it would be desireable, and am working on it, but my
motivation was to provide people with something immediately useful.
Once I get something reasonably efficient worked out, I'll look at
uploading the Haskell code to Hackage, providing JSON data, etc..
Meanwhile if someone wanted to work on their own app or interface,
it's not too hard to get CSV from the table.

I made a mistake and the link was down for about 12 hours.  It's back
now, with a number of improvements and up-to-date hackage info.  It is
an expensive page to run, you may get Script not responding pop-ups
depending on your hardware, but I think it's worth it.

http://fremissant.net/portackage

Kind Reg'ds,
Andrew

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Re: [Haskell-cafe] [Haskell] ANN: Portackage - a hackage portal

2012-04-27 Thread Andrew Seniuk

Excuse the delay, I have no home internet.

 On Fri, Apr 27, 2012 at 1:16 AM,  bri...@aracnet.com wrote:
 Great idea.  Maybe the format can start as compactly as possible,
 i.e. 1 entry per line to make it easy to browse as many entries
 as possible in one page.

 It looks as though disabling just the dependencies would go a
 long way to accomplish that.

Yep, and in fact the version I uploaded while reading your
message has the deps column elided (and one or two others).
Enforcing single-line rows is a but a few tweaks away.

The thing is, the module namespace was the main motivator for
this project, so I'm also seeing whether I can get away with a
single view, package-oriented as presently, and still give good
focus to the modules names.

Soon I hope to include accordion views of the module namespace,
with cookie-based (?) persistent state so user's collapse/expand
tree state is preserved.

 I'd like to vote to make the synopsis to be the second column.

 will each column type have an enable/disable ?

I like the idea (although that one wasn't in the upload).
Hopefully when I explore the JavaScript UI tools a bit more,
the columns (key structure) will be totally configurable
by drag-and-drop, with columns sizable, and keys selected from
a listbox. (?) stuff like that

 it's probably best if a click on a specific target, say the actual
 name of the package, sends you to the hackage entry instead of a
 click anywhere on the row.  I find myself clicking on the page
 by accident and it sending me off to some random hackage entry.

:) That's a feature!

But seriously, you're right, and as a bonus the links can be
specific to the columns (package - hackage, modules - API pages,
homepages - hps, maintainer - sendto [1]).

(A 2-finger or Mod- click anywhere on a row might still be nice, but
a bare tap is admittedly way too accident prone with touch input.)

 I really like the idea - makes your hackage surfing
 much more enjoyable !

 Brian

And thank-you for sharing your thoughts! I'm committed to improving
it, until the ideas run out.

 On Fri, Apr 27, 2012 at 4:12 AM, Christoph Breitkopf 
 chbreitk...@googlemail.com wrote:
 this already looks great. So here's my wish-list, in case you have
 too much time on yours hands ;-)

Thanks! Yes I suppose I do have too much time on my hands, but the
pain of that is conterbalanced by all the excitement.

 Quality/popularity indicators (I'm aware that some of these are
 real work and better provided by hackage itself):
 - used by how many other packages (number of edges to that package
in the dependency graph of all packages)
 - haddock coverage, test coverage, etc.
 - like, +1, whatnot button
 - link to issue tracker, if there is one

If there's interest, this could become integrated with hackage
at some point in the future.

Next thing is to get a last upload field which can replace
the version field. The codependency graph :) would be a nice metric
to add, I'll look into it. I remember seeing a package that does
this someplace on hackage. The +1 button is a good one!

In short I'll try to implement all these ideas, thanks to you both
for the encouraging comments.

-Andrew

[1] I omitted the maintainer column, thinking its inclusion might
 be harmful, making the emails so easy for a bot to collect.

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Re: [Haskell-cafe] [Haskell] ANN: Portackage - a hackage portal

2012-04-27 Thread Andrew Seniuk

Hi Derek,

Thanks for your comments. Yes, I am probably going to focus on making
it work as a web service and stay away from platform-specific mobile
apps. Not been thinking mobile much at all, since the quantities of
data are taxing even to my laptop, and also I'm inclined to believe
people are mostly at a laptop or desktop when coding Haskell.

However, I'm planning to try server-side sorting and filtering, and
compare performance. No DB is used on the server yet, but it would be
simple enough I suppose -- all this is quite new territory for me.
Also my shared hosting resource limits may become a problem if this
gets a lot of use.

On the other hand, was planning to use persistence (cookies i guess?)
to save the data on the client, so that patches based on Hackage RSS
could be applied incrementally. Also, I think the sorting could be
faster by sending per-column lists of indices. But maybe it is just
the browser rendering which is taking all the time?

I'll take this opportunity to announce a few improvements:
 - shift-click a row to see the Hackage page (bare click does nothing)
 - per-column filtering widgets

Presently working on getting the last updated column, this
information is not in a .cabal file but I'm hoping it is in the TAR
metadata...

The link again:  http://www.fremissant.net/portackage

A.

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[Haskell-cafe] ANN: Portackage - a hackage portal

Hello,

This is to announce a provisional webpage to summarise hackage.haskell.org.

http://www.fremissant.net/portackage

It is a lot of data, so will be a bit slow to load. Columns can be
sorted by clicking the headers, but this will also take some seconds
on a typical client. The initial sort is by module name.  Clicking a
table row links to the project page on hackage.

Although I believe this is a complete list of all packages/modules in
hackage, it is probably still buggy, so if you see anything amiss
please let me know. Also, a subsequent version in the near future will
update automatically based on the
http://hackage.haskell.org/packages/archive/recent.rss RSS feed, but
for now it's based on a recent snapshot. Haskell code which prepares
the page will be released after a few more days testing and
refinement.

Some previous work [1] provided a list of all modules, but is not
being maintained, and I was unable to rearouse the author's interest.

Feature requests and suggestions are welcome!

Kind Reg'ds,
Andrew Seniuk

[1] http://folk.ntnu.no/hammar/explore-hackage/

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Re: [Haskell-cafe] [Haskell] ANN: Portackage - a hackage portal

Jonathan,

On Thu, Apr 26, 2012 at 4:13 PM, Jonathan Daugherty j...@galois.com wrote:
 Although I believe this is a complete list of all packages/modules in
 hackage, it is probably still buggy, so if you see anything amiss
 please let me know.

 It might not be showing the most recent releases of everything.  As an
 example, it shows a much older version of my vty-ui library (1.0) and
 its metadata, instead of the latest version, 1.5.  As a result the
 version, module list, description, homepage, etc., are not current.

Thank-you, I'd realised this issue but forgot to address it. It is
due to a false assumption on my part that the .cabal entries in the
00-index.tar file were in increasing version order.

I'll address this problem today.

Cheers,
Andrew

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Re: [Haskell-cafe] [Haskell] ANN: Portackage - a hackage portal

Should be fixed in that respect now, thanks again for pointing it out.

On Thu, Apr 26, 2012 at 4:23 PM, Andrew Seniuk ras...@gmail.com wrote:
 Jonathan,

 On Thu, Apr 26, 2012 at 4:13 PM, Jonathan Daugherty j...@galois.com wrote:
 Although I believe this is a complete list of all packages/modules in
 hackage, it is probably still buggy, so if you see anything amiss
 please let me know.

 It might not be showing the most recent releases of everything.  As an
 example, it shows a much older version of my vty-ui library (1.0) and
 its metadata, instead of the latest version, 1.5.  As a result the
 version, module list, description, homepage, etc., are not current.

 Thank-you, I'd realised this issue but forgot to address it. It is
 due to a false assumption on my part that the .cabal entries in the
 00-index.tar file were in increasing version order.

 I'll address this problem today.

 Cheers,
 Andrew

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Re: [Haskell-cafe] ANN: Portackage - a hackage portal