On Sunday, 3. March 2013 21:11:21 Roman Cheplyaka wrote:
> Admittedly, programming with callbacks is not very pleasant. So we have
> an excellent alternative — the continuation monad transformer!
>
> This nested code
>
> something1 $ \x -> do
> something2 $ \y -> do
>
Hello all,
this was previously posted on Haskell Beginners, but only partially answered.
In Sound.ALSA.Sequencer, there are a number of functions which together set up
a midi environement (client, port, queue). They all have a type, where the
last argument has a type like:
(something.T -> IO a
On Sunday, 24. February 2013 16:04:11 Tillmann Rendel wrote:
> Both approaches are essentially equivalent, of course: Before
> considering the very same nonterminal again, we should have consumed at
> least one token.
I see. Thanks
So for the laymen:
expr ::= expr "+" expr
is a problem, becaus
On Wednesday, 20. February 2013 09:59:47 Tillmann Rendel wrote:
>
> So the grammar is:
>
>Exp ::= Int
>
> | Exp "+" Exp
> >
> > My naive parser enters an infinite recursion, when I try to parse "1+2".
> > I do understand why:
> >
> > "hmm, this expression could be a plus, but the
09:59:47 Tillmann Rendel wrote:
> Hi,
>
> Martin Drautzburg wrote:
> > As an exercise I am writing a parser roughly following the expamples in
> > Graham Hutton's book. The language contains things like:
> >
> > data Exp = Lit Int -- literal integer
> >
Hello all,
this was previously asked on haskell-beginners, but only partially answered.
As an exercise I am writing a parser roughly following the expamples in Graham
Hutton's book. The language contains things like:
data Exp = Lit Int -- literal integer
| Plus Exp Exp
My naive parser
On Thursday, 24. June 2010 00:04:18 Alexander Solla wrote:
> On Jun 23, 2010, at 1:50 PM, Martin Drautzburg wrote:
> > I said that a rhythm is a series of Moments (or Beats), each
> > expressed as
> > fractions of a bar. But each Moment also has volume. So I could
> > m
Hello all,
I am currently playing with Paul Hudak's Euterpea (a music program, formely
called Haskore) and I am trying to teach it about rhythm.
I said that a rhythm is a series of Moments (or Beats), each expressed as
fractions of a bar. But each Moment also has volume. So I could model rhythm
Hello all
The standard map function applies a single function to a list of arguments.
But what if I want to apply a list of functions to a single argument. I can
of course write such a function, but I wonder if there is a standard way of
doing this,
Related to that is the problem, that the fun
On Tuesday, 15. June 2010 19:43:26 Steve Schafer wrote:
> On Tue, 15 Jun 2010 19:23:35 +0200, you wrote:
> >When I know my supplies I want to know what I can produce. When I know
> > what I want to produce I want to know what supplies I need for that. Both
> > kinds of questions should be answered
On Mon, Jun 14, 2010 at 11:16 AM, Martin Drautzburg
>
> wrote:
> > Hello all,
> >
> > this is a problem which has haunted me for some time. If this is simply
> > hillarious, please tell me so. Or it may be some well known unsolvable
> > problem...
> >
>
Hello all,
this is a problem which has haunted me for some time. If this is simply
hillarious, please tell me so. Or it may be some well known unsolvable
problem...
An assembly process takes inputs and produces outputs. I could say a Process
is a function
canProduce :: [Input]->[Output]->Bool
Hello all,
I need your advice about how to browse code which was written by someone else
(Paul Hudak's Euterpea, to be precise, apx. 1 LOC). I had set some hopes
on leksah, and it indeed shows me the interfaces, but I have not yet
convinced it to show me more than that.
I ran haddock over
On Saturday, 12. June 2010 19:06:39 Darrin Chandler wrote:
> On Sat, Jun 12, 2010 at 12:34:37PM -0400, aditya siram wrote:
> > It's weird I was just thinking about LP in Haskell this morning. Check
> > out John Milliken's dbus-core [1] written entirely in noweb.
Okay I'll check out noweb.
My per
Hello all,
Is literate programming something you guys actually do (I only know that Paul
Hudak does), or is it basically a nice idea from days gone by?
In case you do, then how do you do it? Do you use lhs2TeX or what? Do you
use "bird" style of full-blown LaTeX?
Does any of you use leksah? I
On Friday, 11. June 2010 00:12:03 Daniel Fischer wrote:
Thanks Daniel.
> Upgrade. We're at 6.12 now!
Did that. Everything is available now.
I am still having trouble with the test function. First it seems I need
braces, so I can mix == and <*>.
test :: Num a
=> (a -> a) -> (a -> a) -> (a
On Thursday, 10. June 2010 22:10:08 Maciej Piechotka wrote:
Wow!
this is somewhat above my level. I guess I need to go back to the books. I'll
document my ignorance nontheless.
> data Named a = Named String a
>
> instance Functor Named where
> f `fmap` (Named s v) = Named s (f v)
>
okay so
On Thursday, 10. June 2010 00:08:34 Luke Palmer wrote:
> Or just:
>
> apply = val_of
> So, to summarize: if you have something that isn't a function and you
> want to use it like a function, convert it to a function (using
> another function :-P). That's all. No syntax magic, just say what
> y
On Monday, 7. June 2010 23:28:08 Evan Laforge wrote:
> I just meant you could add instances:
>
> instance Functor (Named a) where fmap f named = named { val_of = f
> (val_of named) }
> instance Applicative (Named a) where ... likewise, but maybe not a
> great fit unless you have a "no name" for 'p
Hello all,
I like some of the naming conventions in haskell quite a lot, like calling a
list of something "xs", or function which takes a function as a
parameter "..By" as in sortBy or groupBy.
If I have a function, say "compute" whose last parameter is some value ...
and I create another funct
On Friday, 4. June 2010 18:02:15 Daniel Fischer wrote:
> On Friday 04 June 2010 17:37:16, Martin Drautzburg wrote:
> > Dear all,
> >
> > If I have a problem where I have to select from a set of operations, how
> > would I print the result?
> >
> > Example: I
Dear all,
If I have a problem where I have to select from a set of operations, how would
I print the result?
Example: If I can chose from (x+y), (x*y), (x^2+y)...
and I feed them all into my problem solver
and it finds that "(x*y) is right", how can I print that string?
--
Martin
_
Inspired by this post I looked at the language shootout. There is one thing
which strikes me: On
http://shootout.alioth.debian.org/u64/performance.php?test=spectralnorm#about
It sais for the spectralnorm benchmark that both Haskel GHC #4 and HaskellGHC
produce "bad output". For GHC I connt see
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