Before there was lens there was lens-family
I'm pleased to announce the second major release of
the lens-family pacakges: lens-family-core-1.0.0 and lens-family-1.0.0.
They can be found at
* http://hackage.haskell.org/package/lens-family-core
*
On Mon, 21 Jan 2013, rocon...@theorem.ca wrote:
On Mon, 21 Jan 2013, Karel Gardas wrote:
On 01/21/13 12:49 AM, rocon...@theorem.ca wrote:
On Sun, 20 Jan 2013, Karel Gardas wrote:
Okay, I patched the settings filed generted by ./configure in the
binary-dist and rank make install which
On Mon, 21 Jan 2013, Karel Gardas wrote:
On 01/21/13 12:49 AM, rocon...@theorem.ca wrote:
On Sun, 20 Jan 2013, Karel Gardas wrote:
Okay, I patched the settings filed generted by ./configure in the
binary-dist and rank make install which completed. However,
pi@raspberrypi /tmp/bindist $
On Wed, 16 Jan 2013, Karel Gardas wrote:
You should not IMHO. My patch should solve all your issues. :-) The only
issue you may get is that your distro ghc will compile for soft-float ABI and
your compiled GHC will compile to hard-float and object files will get mixed
somewhere. But I trust
On Sun, 20 Jan 2013, Karel Gardas wrote:
On 01/20/13 07:17 PM, rocon...@theorem.ca wrote:
On Wed, 16 Jan 2013, Karel Gardas wrote:
You should not IMHO. My patch should solve all your issues. :-) The
only issue you may get is that your distro ghc will compile for
soft-float ABI and your
On Sun, 20 Jan 2013, Karel Gardas wrote:
On 01/20/13 07:50 PM, rocon...@theorem.ca wrote:
Karel, maybe you should try deploying a binary-dist on your panda board?
Sorry? What's binary-dist? And why I should do that? And what
exactly do you mean by deploying? And on what OS? Ubuntu or
On Sun, 20 Jan 2013, Karel Gardas wrote:
On 01/20/13 07:17 PM, rocon...@theorem.ca wrote:
On Wed, 16 Jan 2013, Karel Gardas wrote:
You should not IMHO. My patch should solve all your issues. :-) The
only issue you may get is that your distro ghc will compile for
soft-float ABI and your
On Sun, 20 Jan 2013, Karel Gardas wrote:
On 01/20/13 08:27 PM, rocon...@theorem.ca wrote:
Looks like you do have corrupted settings file. Recover it by adding
HARD following armABI = , so result should be:
ArchARM {armISA = ARMv6, armISAExt = [VFPv2], armABI = HARD}
Okay, I patched the
On Sun, 20 Jan 2013, Karel Gardas wrote:
On 01/20/13 08:27 PM, rocon...@theorem.ca wrote:
Looks like you do have corrupted settings file. Recover it by adding
HARD following armABI = , so result should be:
ArchARM {armISA = ARMv6, armISAExt = [VFPv2], armABI = HARD}
Okay, I patched the
On Thu, 17 Jan 2013, rocon...@theorem.ca wrote:
On Thu, 17 Jan 2013, Austin Seipp wrote:
There have been a few of these bugs recently it seems. If you could:
use the stage1 compiler to compile a simple executable, like 'main =
return ()' or hello world or whatever.
The stage1 compiler can be
On Fri, 18 Jan 2013, Karel Gardas wrote:
On 01/18/13 05:49 PM, rocon...@theorem.ca wrote:
I don't know much about gdb, but
$ /usr/bin/gdb /tmp/Main
GNU gdb (GDB) 7.4.1-debian
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
On Wed, 16 Jan 2013, Karel Gardas wrote:
On 01/16/13 08:12 PM, rocon...@theorem.ca wrote:
On Wed, 16 Jan 2013, Karel Gardas wrote:
Good! So the patch I already provided is working fine at least w.r.t.
change in configure. I've tested it here on my raspbian chroot on
pandaboard where I've
On Thu, 17 Jan 2013, Austin Seipp wrote:
There have been a few of these bugs recently it seems. If you could:
use the stage1 compiler to compile a simple executable, like 'main =
return ()' or hello world or whatever.
The stage1 compiler can be located in the build directory, under
On Wed, 16 Jan 2013, Karel Gardas wrote:
Guys,
I've installed raspbian into ubuntu chroot on my panda. Now to simulate what
GHC detects on your hardware, could you be so kind and send me output of:
uname -m
armv6l
uname -r
3.6.11+
uname -s
Linux
uname -v
#346 PREEMPT Fri Dec
On Wed, 16 Jan 2013, Karel Gardas wrote:
Good! So the patch I already provided is working fine at least w.r.t. change
in configure. I've tested it here on my raspbian chroot on pandaboard where
I've hacked config.guess to print exactly what you get on real rpi.
Now, I'm curious if the hack
On Mon, 14 Jan 2013, Thijs Alkemade wrote:
Op 14 jan. 2013, om 17:30 heeft rocon...@theorem.ca het volgende geschreven:
On Thu, 10 Jan 2013, Karel Gardas wrote:
Hmm, are you using Raspbian? I.e. hard-float abi caught my eye in case of
ARMv6/ARM11 chip here...
I'm afraid LLVM is not well
On Tue, 15 Jan 2013, Thijs Alkemade wrote:
Op 15 jan. 2013, om 17:36 heeft rocon...@theorem.ca het volgende geschreven:
Okay, I tried:
SRC_HC_OPTS= -H64m -Rghc-timing -optc-mfloat-abi=hard -optc-march=armv6
-optc-mfpu=vfp -optlc=-mattr=+vfp2
GhcStage1HcOpts= -O -fllvm
In theory we could try a couple variations of builds at the same time.
But at the moment, I'm running low on ideas on what to try.
I just got the, extensive, raspbian patches for 7.4.1 and I'm going to
browse through them when I get time (apt-get source ghc).
On Tue, 15 Jan 2013, Neil Davies
On Thu, 10 Jan 2013, Karel Gardas wrote:
Hmm, are you using Raspbian? I.e. hard-float abi caught my eye in case of
ARMv6/ARM11 chip here...
I'm afraid LLVM is not well guided in your case so could you be so kind and
test if adding -optlc=-mattr=+vfp2 helps? You need to add it to your
On Sun, 13 Jan 2013, Neil Davies wrote:
Sounds like we're close - I must admit I've slightly lost track of the things
that need to be done.
Can we start collecting the pre-conditionds and steps, when each complete build
takes best part of a day, its difficult to keep the context.
So -
I've tried to build 6.12.3, 7.4.1, 7.4.2, and 7.6.1, with a few various
patches, and I'm stuck in the final stage with errors like:
/usr/bin/ld: error: libraries/ghc-prim/dist-install/build/cbits/debug.o uses
VFP register arguments,
libraries/ghc-prim/dist-install/build/HSghc-prim-0.3.0.0.o
On Thu, 10 Jan 2013, Karel Gardas wrote:
Hmm, are you using Raspbian? I.e. hard-float abi caught my eye in case of
ARMv6/ARM11 chip here...
I'm afraid LLVM is not well guided in your case so could you be so kind and
test if adding -optlc=-mattr=+vfp2 helps? You need to add it to your
On Sat, 12 Jan 2013, rocon...@theorem.ca wrote:
On Thu, 10 Jan 2013, Karel Gardas wrote:
Hmm, are you using Raspbian? I.e. hard-float abi caught my eye in case of
ARMv6/ARM11 chip here...
I'm afraid LLVM is not well guided in your case so could you be so kind and
test if adding
What version of GHC did you build?
On Sat, 12 Jan 2013, Ben Gamari wrote:
Karel Gardas karel.gar...@centrum.cz writes:
On 01/11/13 09:25 PM, rocon...@theorem.ca wrote:
On Thu, 10 Jan 2013, Karel Gardas wrote:
Hmm, are you using Raspbian? I.e. hard-float abi caught my eye in case
of
On Sat, 12 Jan 2013, Ben Gamari wrote:
rocon...@theorem.ca writes:
What version of GHC did you build?
This was building from the ghc-7.4 branch. That being said, after this
build finished I noticed that the resulting stage 2 compiler wasn't
invoking llc with the correct parameters,
On Thu, 10 Jan 2013, Karel Gardas wrote:
Hmm, are you using Raspbian? I.e. hard-float abi caught my eye in case of
ARMv6/ARM11 chip here...
I'm afraid LLVM is not well guided in your case so could you be so kind and
test if adding -optlc=-mattr=+vfp2 helps? You need to add it to your
Thanks for the advice; However, it had little effect.
I now have the errors:
===--- building final phase
make -r --no-print-directory -f ghc.mk phase=final all
LD libraries/ghc-prim/dist-install/build/HSghc-prim-0.3.0.0.o
/usr/bin/ld: error:
This is the settingings file:
$ cat settings
[(GCC extra via C opts, -fwrapv),
(C compiler command, /usr/bin/gcc),
(C compiler flags, -fno-stack-protector -Wl,--hash-size=31
-Wl,--reduce-memory-overheads),
(ar command, /usr/bin/ar),
(ar flags, q),
(ar supports at file, YES),
(touch
On Thu, 3 Jan 2013, Thijs Alkemade wrote:
I believe I had the same problem, which disappeared after upgrading llvm from
3.0 to 3.1, and using that instead for ./configure.
Hope this helps,
Thijs
Thanks, using LLVM 3.1 seems to have improved the siutation, but I'm
running into a new error.
I'm trying to build ghc-7.4.1 using ghc-7.4.1 on my raspberry pi (armv6l)
and I get the following error:
inplace/bin/ghc-stage1 -H32m -O-package-name ghc-prim-0.2.0.0
-hide-all-packages -i -ilibraries/ghc-prim/. -ilibraries/ghc-prim/dist-install/build
Thanks for your help, but unfortunately this isn't the issue
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 924G 584G 294G 67% /tmp
So there is pleanty of room on temp.
BTW, I also tried building it twice and I got the same error at the same
place.
On Wed, 2 Jan 2013,
Some further information it seems that llc is segfaulting:
pi@raspberrypi /tmp/ghc-7.4.1 $ llc -O3 -relocation-model=static /tmp/ghc7189_0/ghc7189_0.bc -o /tmp/ghc7189_0/ghc7189_0.lm_s
Stack dump:
0. Program arguments: llc -O3 -relocation-model=static /tmp/ghc7189_0/ghc7189_0.bc -o
On Tue, 10 Jul 2012, Sönke Hahn wrote:
Hi!
I've discovered a strange bug that violates simple equational reasoning.
Basically, something similar to this:
let a = f x
in a == f x
While this code as it stands doesn't quite illustrate the referential
transparency error, since == isn't
On Fri, 6 Jul 2012, Dan Burton wrote:
Following the announcement of lens-family, I'm pleased to announce
lens-family-th 0.1.0.0, a Template Haskell library supplying macros to generate
lens-family lenses for fields of data types declared with record syntax.
Be warned that currently, type
On Fri, 6 Jul 2012, Dan Burton wrote:
Following the announcement of lens-family, I'm pleased to announce
lens-family-th 0.1.0.0, a Template Haskell library supplying macros to generate
lens-family lenses for fields of data types declared with record syntax.
Be warned that currently, type
I don't know if it is possible to add haddock to functions whose type
signatures are generated by template haskell.
Could the documentation be an argument of mkLenses?
Does haddock run on the template-haskell expanded code?
--
Russell O'Connor
I'm pleased to announce the first release of lens-family-core and
lens-family.
This package provide first class(†) functional references. In addition to
the usual operations of getting, setting and composition, plus integration
with the state monad, lens families provide some unique features:
I'm pleased to announce the first release of lens-family-core and
lens-family.
This package provide first class(†) functional references. In addition to
the usual operations of getting, setting and composition, plus integration
with the state monad, lens families provide some unique features:
In less than 5 minutes I can solve NP-Complete problems in restaurant
orders:
http://www.reddit.com/comments/24p2c/xkcd_does_anyone_else_feel_compelled_to_solve_this/c24pc5
On Mon, 27 Feb 2012, Arnaud Bailly wrote:
Hello Cafe,
I will be (re)presenting Haskell in a Batlle Language event
On Wed, 21 Dec 2011, Erik Hesselink wrote:
How does this relate to the Maybe lenses in fclabels [1]?
Erik
[1]
http://hackage.haskell.org/packages/archive/fclabels/1.0.4/doc/html/Data-Label-Maybe.html
It appears to be somewhere between similar and the same.
*** Comparison of API
Do you miss null references from your old imperative programming days?
Wish that the worlds best imperative language had null references? Now
your wishes have come true with the new partial-lens package!
partial-lens augment edwardk's data-lens package with partial lens.
Partial lenses are
Do you miss null references from your old imperative programming days?
Wish that the worlds best imperative language had null references? Now
your wishes have come true with the new partial-lens package!
partial-lens augment edwardk's data-lens package with partial lens.
Partial lenses are
On Tue, 20 Sep 2011, Alexander Solla wrote:
On Tue, Sep 20, 2011 at 1:22 PM, Jake McArthur jake.mcart...@gmail.com wrote:
On Tue, Sep 20, 2011 at 3:48 PM, Chris Smith cdsm...@gmail.com wrote:
But it would be the *wrong* thing to use as a desugaring for list range
notation.
On Sat, 27 Aug 2011, Sönke Hahn wrote:
Hi!
I was reading through the Typeclassopedia ([1]) and I was wondering which
type could be an instance of Pointed, but not of Applicative. But I can't
think of one. Any ideas?
(Identity :+: Store s) is a comonad that is also instance of Pointed, but
On Wed, 31 Aug 2011, rocon...@theorem.ca wrote:
On Sat, 27 Aug 2011, Sönke Hahn wrote:
Hi!
I was reading through the Typeclassopedia ([1]) and I was wondering which
type could be an instance of Pointed, but not of Applicative. But I can't
think of one. Any ideas?
(Identity :+: Store s)
On Tue, 11 Jan 2011, Simon Marlow wrote:
Thanks for this. I distilled your example into a shell script that uses git,
and demonstrates that git gets the merge wrong:
http://hpaste.org/42953/git_mismerge
I've posted an annotation at
On Thu, 2 Dec 2010, Petr Pudlak wrote:
Hi,
recently, I was studying how cartesian closed categories can be used to
describe typed functional languages. Types are objects and morphisms are
functions from one type to another.
Since I'm also interested in systems with dependent types, I
Multiplate is a lightweight generic library for mutually recursive data
types that won't make Conor lose his lunch.
Multiplate is an alternative extension of the Uniplate/Compos core design
to support mutually recursive datatypes in a way that is as powerful as
Compos, almost as easy to use
On Thu, 11 Nov 2010, Dan Doel wrote:
intensional equality: two values are provably equal if they evaluate to the
same normal form
extensional equality: this incorporates non-computational rules, like the
point-wise equality of functions.
Now, in a type theory where equality is
See http://www.haskell.org/pipermail/haskell/2006-September/018497.html
On Fri, 12 Nov 2010, Petr Pudlak wrote:
On Fri, Nov 12, 2010 at 07:52:53PM +0100, Petr Pudlak wrote:
Hi, I was playing with the following example I found in D.A.Turner's paper
Total Functional Programming:
data Bad a =
On Sat, 6 Nov 2010, Sebastian Fischer wrote:
Hello,
I'm curious and go a bit off topic triggered by your statement:
On Nov 6, 2010, at 12:49 PM, rocon...@theorem.ca wrote:
An applicative functor morphism is a polymorphic function,
eta : forall a. A1 a - A2 a between two applicative functors
An applicative functor morphism is a polymorphic function,
eta : forall a. A1 a - A2 a between two applicative functors A1 and A2
that preserve pure and *:
eta (pure c) = pure c
eta (f * x) = eta f * eta x
What do you guys call such a thing? My leading candidate is idomatic
transformation.
I was one of the people on #haskell discussing this with Anupam.
Note that that when you remove the signature of d, the result complies and
ghci will state the inferred type of d is exactly the signature that you
are not allowed to write.
In my opinion, this is a bug in the Haskell 98 report
On Fri, 14 May 2010, Derek Elkins wrote:
You did it wrong. All you did was Church encode the Either type.
Your bind is still doing a case-analysis. All you have to do is use
ContT r (Either e). The bind implementation for ContT is completely
independent of the underlying monad. It doesn't
On Fri, 16 Apr 2010, jerzy.karczmarc...@info.unicaen.fr wrote:
Somebody finally decided to ridiculise the system. If you want a good laugh,
see the patent 6,368,227. The search site is here:
As I recall some (patent?) laywer was simply teaching his kid how the
patent process worked, so the
On Thu, 15 Apr 2010, Maciej Piechotka wrote:
Are
f 0 = 1
f n = f (n - 1) + f (n - 2)
and
g 0 = 1
g n | n 0 = g (n - 1) + g (n - 2)
| n 0 = g (n + 2) - g (n + 1)
The same (morally) function?
Are:
f x = 2*x
and
f x = undefined
The same function
Try using the (x == y) == (f x = g
On Wed, 14 Apr 2010, Ashley Yakeley wrote:
On 2010-04-14 14:58, Ashley Yakeley wrote:
On 2010-04-14 13:59, rocon...@theorem.ca wrote:
There is some notion of value, let's call it proper value, such that
bottom is not one.
In other words bottom is not a proper value.
Define a proper value
On Wed, 14 Apr 2010, Ashley Yakeley wrote:
Joe Fredette wrote:
this is bounded, enumerable, but infinite.
The question is whether there are types like this. If so, we would need a new
class:
class Finite a where
allValues :: [a]
instance (Finite a,Eq b) = Eq (a - b) where
p == q
On Wed, 14 Apr 2010, Ashley Yakeley wrote:
On 2010-04-14 03:41, rocon...@theorem.ca wrote:
For example (Int - Bool) is a perfectly fine Compact set that isn't
finite
Did you mean Integer - Bool? Int - Bool is finite, but large.
Yes, I meant Integer - Bool.
--
Russell O'Connor
On Wed, 14 Apr 2010, Ashley Yakeley wrote:
On 2010-04-14 13:03, Alexander Solla wrote:
If you're willing to accept that distinct functions can represent the
same moral function, you should be willing to accept that different
bottoms represent the same moral value.
Bottoms should not be
On Thu, 13 Aug 2009, rocon...@theorem.ca wrote:
Actually you need five versions: The pure version, the pre-order traversal,
the post-order traversal, the in-order traversal, and the reverse in-order
traversal. And that is just looking at syntax. If you care about your
semantics you could
On Wed, 12 Aug 2009, Peter Verswyvelen wrote:
I kind of agree with the DDC authors here; in Haskell as soon as a
function has a side effect, and you want to pass that function to a
pure higher order function, you're stuck, you need to pick the monadic
version of the higher order function, if it
On Thu, 6 Aug 2009, Jeff Heard wrote:
I was wondering if Data.Colour supported Double-valued colour
components 1.0 or less than 0. I'm looking to create an HDR image
processing library, and Haskell has one of the most extensive and
correct colour models around, thanks to Russell. With 16bpcc
On Thu, 6 Aug 2009, rocon...@theorem.ca wrote:
On Thu, 6 Aug 2009, Jeff Heard wrote:
I was wondering if Data.Colour supported Double-valued colour
components 1.0 or less than 0. I'm looking to create an HDR image
processing library, and Haskell has one of the most extensive and
correct
Max Rabkin wrote:
On Sat, Jul 4, 2009 at 8:38 PM, Andrew
Coppinandrewcoppin at btinternet.com wrote:
A few reasons:
1. I never knew it existed. ;-)
A good reason. However, it's good to do a quick search over Hackage
before uploading (or before writing) so you know what's out there.
Also,
On Thu, 9 Jul 2009, rocon...@theorem.ca wrote:
You can use by lib without worrying about the CIE. You can use my library
without ever importing or using the word CIE. However, the CIE stuff is
there for those who need it.
Perhaps I (maybe with some help) need to make a tutorial on the
I wanted to pass this idea around the cafe to get some thoughts before
submitting a trac on this topic.
I'd like to see the mtl removed from the Haskell Platform.
The mtl was a tremendous step forward when it was developed. However, we
have learned a few things about monad transformers since
On Wed, 25 Mar 2009, Thomas Hartman wrote:
With the state version, there's a lot of behind-the-scenes magic, and
as we've seen, things can go wrong.
Also, the issue isn't infinite lists, but lists that are longer than
the sum of the partitions provided. The state monad partition version
goes
I also recommend reading
http://www.haskell.org/haskellwiki/IO_Semantics (mostly because I wrote
it). Feel free to improve upon it.
--
Russell O'Connor http://r6.ca/
``All talk about `theft,''' the general counsel of the American Graphophone
Company wrote,
On Fri, 23 Jan 2009, Luke Palmer wrote:
For example, it is possible to prove that foldr mappend mempty (x:xs) =
foldr1 mappend (x:xs). Which means that anywhere in the source where we see
the former, we can clean it up to the latter. However, if monad laws
don't apply to partial values, then
On Sat, 24 Jan 2009, Lennart Augustsson wrote:
You can dream up any semantics you like about bottom, like it has to
be () for the unit type.
But it's simply not true. I suggest you do some cursory study of
denotational semantics and domain theory.
Ordinary programming languages include
On Sat, 24 Jan 2009, Jake McArthur wrote:
What you said makes little sense to me either. ;) But I will try to fit the
pieces together as best I can.
It appears to me that you may be talking about isomorphisms between the
concepts we try to map to data types and the data representations
On Sun, 25 Jan 2009, Lauri Alanko wrote:
On Fri, Jan 23, 2009 at 08:10:38PM -0500, rocon...@theorem.ca wrote:
I'd like to argue that laws, such as monoid laws, do not apply to partial
values. But I haven't thought my position through yet.
Before you do, you may want to read Fast and Loose
On Fri, 23 Jan 2009, Derek Elkins wrote:
mempty `mappend` undefined = undefined (left identity monoid law)
The above definition doesn't meet this, similarly for the right identity
monoid law. That only leaves one definition, () `mappend` () = () which
does indeed satisfy the monoid laws.
So
Thanks for letting me reflect on this.
I assume that my final program (my final value) is always a total value.
Anything else is an error. Therefore, if we required relaxed monoid laws
of the form
x `mappend` mzero = x
then we could safely substitute (x `mappend` mzero) by x without
On Sun, 18 Jan 2009, Ross Paterson wrote:
Anyone can check out the darcs repos for the libraries, and post
suggested improvements to the documentation to librar...@haskell.org
(though you have to subscribe). It doesn't even have to be a patch.
Sure, it could be smoother, but there's hardly a
On Sat, 17 Jan 2009, David Menendez wrote:
instance Applicative f = Applicative (Backwards f) where
pure = B . pure
f * x = B (unB f ** unB x)
probably should be f * x = B (unB x ** unB f)
anyhow, this should be part of Control.Applicative.
This may be terminological confusion. I
What I don't understand is why Monoid and Monad are objectionable, while
Hash, Vector, Boolean, and Integer are (presumably) not objectionable.
They all appear equally technical to me.
--
Russell O'Connor http://r6.ca/
``All talk about `theft,''' the
On Fri, 2 Jan 2009, Achim Schneider wrote:
There are no lazy monads. Monads imply explicit sequencing... writing
I think this is an extremely bad thing to say and is a source of
misunderstanding about monads and evaluation. Most monads _are_ lazy, and
it is important to understand that
On Fri, 24 Oct 2008, Sebastian Sylvan wrote:
It would be nice if we could customize the gamma curve. Different devices have
different gamma.
Some hardware even approximates the gamma curve with piecewise linear
functions. This can make a
massive difference if you, e.g. degamma the image
On Fri, 24 Oct 2008, Sebastian Sylvan wrote:
Another useful predefined space which I didn't see is the YCoCg space, which is
used in lots of
compression schemes (like H.264 IIRC).
YCoCg, like HLS and HSV, seems to not really be a colour space because it
isn't well specified. A
http://hackage.haskell.org/cgi-bin/hackage-scripts/package/colour-0.0.0
I hope for this library to become the standard colour library for Haskell.
Most software does not properly blend colours because they fail to
gamma-correct the colours before blending. Hopefully by using this
library,
On Tue, 17 Oct 2006, John Meacham wrote:
On Mon, Oct 09, 2006 at 03:54:41PM +0100, Ian Lynagh wrote:
It might be possible, but it sounds tricky. I guess it would have to go
something like try inlining this, run the simplifier, see if it got
small enough, if not back out, which could waste a
Although this doesn't answer your question, I think it is releated. When
implementing SHA, I need to create a recursive function to append the
length of a string to the string. This function needed to be strict,
because it needed to accumulted the length of the string, and it needed to
be
On Mon, 16 Oct 2006, Simon Marlow wrote:
There's one restriction that I know of: you should be careful not to cast a
function value to a non-function type (except a polymorphic type), because
the two have incompatible representations when it comes to seq and case.
And of course, you should
On Wed, 11 Oct 2006, Simon Peyton-Jones wrote:
Correct. GHC generates
case (x# =# 0#) of { True - ...; False - ... }
But the argument discount only applies when we have
case y of { ... }
So you really want a discount for the args of a primop.
Do you think it should be that
On Wed, 11 Oct 2006, Simon Peyton-Jones wrote:
The constant-folding rules for the primops are all in
prelude/PrelRules.lhs
in function primOpRules. Please add more rules. For example, I see
that
x +# 0 = x
is not in there!
It is in libraries/base/GHC/Base.lhs
x# +# 0#
On Wed, 11 Oct 2006, Samuel Bronson wrote:
branch. I've got a patch that seems like it ought to do a bettter job,
but it doesn't seem to give the $wrotate functions any discount (the
$wshift functions having been tagged by the {-# INLINE shift #-} pragmas
I added all over). Unfortunately I
On Tue, 10 Oct 2006, Simon Peyton-Jones wrote:
That's precisely what GHC does. My explanation before was too brief,
sorry. The algorithm is described in Secrets of the GHC inliner
http://research.microsoft.com/%7Esimonpj/Papers/inlining/index.htm
But it still only makes a specialised copy if
On Mon, 9 Oct 2006, Simon Peyton-Jones wrote:
Turns out that 'shift' is just too big to be inlined. (It's only called
once, but you have exported it too.)
You can see GHC's inlining decisions by saying -ddump-inlinings.
To make GHC keener to inline, use an INLINE pragma, or increase the
Okay, when I force inlining for shift, (and I even need to do it for
shiftR!) then the code is inlined in C. However this isn't the behaviour I
want. Ideally the inlining should only happen when/because the second
argument of shift is constant and the system knows that it can evaluate the
case
Consider the following GHC code:
module Main where
import GHC.Word
import GHC.Base
import GHC.Prim
import Random
a `shiftRLT` b | b =# 32# = int2Word# 0#
| otherwise = a `uncheckedShiftRL#` b
(W32# x#) `shift` (I# i#)
| i# =# 0#= W32# (narrow32Word# (x#
according to http://darcs.haskell.org/packages/base/GHC/Word.hs, GHC's
rotate is implemented as
(W32# x#) `rotate` (I# i#)
| i'# ==# 0# = W32# x#
| otherwise = W32# ((x# `shiftL32#` i'#) `or32#`
(x# `shiftRL32#` (32# -# i'#)))
where
On Tue, 18 Jul 2006, Duncan Coutts wrote:
On Tue, 2006-07-18 at 09:44 -0400, [EMAIL PROTECTED] wrote:
Would the problematic semantics of seq be resolved if seq did nothing on
function types? That is to say
seq (\x - undefined `asTypeOf` x) y reduced to y
and
seq (undefined `asTypeOf` id) y
On Wed, 19 Jul 2006, Duncan Coutts wrote:
Ah ok, I misunderstood. Well that'd be a bit odd too. No other function
behaves differently on different types except by use of type classes.
I agree it is quite odd, but the seq we have is already quite odd.
Furthermore, the fact is that seq on
Would the problematic semantics of seq be resolved if seq did nothing on
function types? That is to say
seq (\x - undefined `asTypeOf` x) y reduced to y
and
seq (undefined `asTypeOf` id) y also reduced to y
--
Russell O'Connor http://r6.ca/
``All talk
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
How about making default method for asin
asin x = atan(x/sqrt(1-x^2))
Can't be worse than the default for (**) ;-)
- --
Russell O'Connor[EMAIL PROTECTED]
http://www.math.berkeley.edu/~roconnor
))
That's a good idea too.
Is there a reason for defining acosh as above instead of
acosh x = log(x + sqrt(x*x-1))
- --
Russell O'Connor[EMAIL PROTECTED]
http://www.math.berkeley.edu/~roconnor/
``This is not a time, as it is never a time, to seek vengeance, but a
time
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