Re: [Haskell-cafe] How to throw an error if using cabal-install version XYZ?
constraining it to = 1.17 would be better while 1.18 isn't out yet..
On Thu, May 23, 2013 at 1:42 AM, Roman Cheplyaka r...@ro-che.info wrote:
Perhaps I'm missing something, but why not just
cabal-version: =1.18
?
It will constrain the Cabal version, not cabal-install, but judging from
the fix[1] this is what you actually need.
[1]:
https://github.com/haskell/cabal/commit/d148336e97cda2e3585c453cf9af61bc3635131a
Roman
* Ryan Newton rrnew...@gmail.com [2013-05-22 22:50:08-0400]
A cabal-install bug https://github.com/haskell/cabal/issues/1284 was
fixed recently that pertains to building C libraries with profiling.
As a result, I want a certain
packagehttp://hackage.haskell.org/package/atomic-primops-0.1.0.2to
test if cabal-install 0.17.0 is used, and throw a preemptive error.
Otherwise this package fails in weird ways at runtime (it's a nasty
one).
I noticed with some surprise the following sequence:
* $ cabal --version*
* cabal-install version 1.16.0.2*
* using version 1.16.0.3 of the Cabal library*
* $ cabal clean*
* $ cabal install*
* $ cat dist/build/autogen/cabal_macros.h | grep VERSION_Cabal*
* #define VERSION_Cabal 1.17.0*
Alright, so that, in retrospect, makes sense. The version is which *my*
library is linked with is the relevant one, not the one cabal-install was
linked with [1].
So the natural next thought is to move the MIN_VERSION_Cabal test into
Setup.hs, and force cabal to use it by setting the build type to Custom.
But... I just learned from this ticket that the cabal macros are not
available in Setup.hs:
http://hackage.haskell.org/trac/hackage/ticket/326
Uh oh, what's left?
-Ryan
[1] P.S. Personally I'm now using a bash function like below, to force
the
two versions to be the same:
function safe_cabal_install () {
VER=`cabal --version | tail -n1 | awk '{ print $3 }'`
cabal install --constraint=Cabal==$VER $*
}
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Re: [Haskell-cafe] question about type constructors
* TP paratribulati...@free.fr [2013-05-23 00:34:57+0200]
Hi,
In the program I am trying to write, I have a problem that can be reduced to
the following dummy example:
--
{-# LANGUAGE GADTs #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE IncoherentInstances #-}
class PrettyPrint a where
prettify :: a - String
data Gender = Male | Female | Gender3 | Gender4
data Person :: Gender - * where
Person :: String - Person b
Child :: String - Person a - Person b - Person c
instance PrettyPrint (Person a)
instance PrettyPrint (Person Male) where
prettify (Person name) = My name is ++ (show name)
++ and I am a male
prettify (Child name person1 person2) = My name is ++ (show name)
++ and my parents are: ++ (prettify person1) ++ ,
++ (prettify person2)
main = do
let p1 = Person Jim :: Person Male
let p2 = Person Joe :: Person Male
let p3 = Child Jack p1 p2
print $ prettify p1
print $ prettify p2
print $ prettify p3
--
The idea is that I want to implement PrettyPrint only for a subset of the
possible types in Gender (through promotion process). Why? It would be
longer to explain (it is a bit more complicated in my real program).
Anyway, in the program above, I have found that with IncoherentInstances
(and the empty instance definition for (Person a)), it is working, it is
able to use the most specific instance corresponding to the current type (I
don't know exactly why). For example, p1 and p2 are correctly printed above,
because they are of type (Person Male) and because I have implemented
PrettyPrint for (Person Male).
But it does not work for p3, I obtain an error at runtime:
-
$ runghc test.hs
My name is \Jim\ and I am a male
My name is \Joe\ and I am a male
test_typelost.hs: test_typelost.hs:16:10-31: No instance nor default method
for class operation Main.prettify
-
The reason is that the information that p1 and p2 are Male seems to be
lost when we construct the child Child Jack p1 p2, probably because
GHC only sees that in the type signature of Child, we have a more general
(Person a) - (Person b). So he tries to find an implementation of prettify
in PrettyPrint (Person a), but there is none.
Is there any workaround?
The rule of thumb is that you should never use IncoherentInstances.
The proper way to do it is:
data Person :: Gender - * where
Person :: String - Person b
Child
:: (PrettyPrint a, PrettyPrint b)
= String - Person a - Person b - Person c
Roman
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Re: [Haskell-cafe] HTML framework for web-ui
Hi Heinrich, Looks simple and interesting. I browsed the git, but not much docs yet. Just examples, or have I looked at wrong places? I see that API is still under heavy design. When do you expect the API might stabilize? (BTW, examples in Readme do not work.) vlatko Vlatko Basic wrote: I'd like to start using web pages as the UI for apps. I found out for yesod, snapp and happstack as the candidates. Would you recommend any of them as better for app ui (not classical web pages)? Or maybe another one? Not sure if that's what you are looking for, but with help from Daniel Austin, I'm currently working on a small GUI library that use the web browser to display GUI elements. https://github.com/HeinrichApfelmus/threepenny-gui It's derived from Chris Done's former Ji project. It's not quite ready for public consumption yet, but any feedback is appreciated, of course. Best regards, Heinrich Apfelmus -- http://apfelmus.nfshost.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANNOUNCE: new bridge! (prelude-prime)
I liked Andreas's idea (cited below). Hence the new package
prelude-prime.
https://github.com/feuerbach/prelude-prime
http://hackage.haskell.org/package/prelude-prime
Pull requests are welcome, but let's stick to widely agreed changes
(like the Foldable/Traversable one). I think one of the reasons why
other Preludes haven't been adopted is because they were too radical.
Let's see whether people here can put their code where their mouth is :)
Roman
* Andreas Abel andreas.a...@ifi.lmu.de [2013-05-20 13:26:05+0200]
Maybe instead of fiddling with the current Prelude (which might break
backwards compatibility), we should design a new prelude which is not
automatically loaded but contains roughly the current prelude (with
the list functions generalized to collections) plus the modern type
class stack: Functor, Applicative, Monad, Foldable, Traversable,
Monoid etc.
I am willing to write
{-# LANGUAGE NoImplicitPrelude #-}
import Base
if I get a decent, modern standard set of functions that could be
considered as the base vocabulary of modern Haskell programmers...
I just do not want to think about the democratic process involved in
this design...
Cheers,
Andreas
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Re: [Haskell-cafe] ANNOUNCE: new bridge! (prelude-prime)
I wish it was possible to use an extension
CustomPrelude = Prelude.Prime
In the cabal file
2013/5/23 Roman Cheplyaka r...@ro-che.info
I liked Andreas's idea (cited below). Hence the new package
prelude-prime.
https://github.com/feuerbach/prelude-prime
http://hackage.haskell.org/package/prelude-prime
Pull requests are welcome, but let's stick to widely agreed changes
(like the Foldable/Traversable one). I think one of the reasons why
other Preludes haven't been adopted is because they were too radical.
Let's see whether people here can put their code where their mouth is :)
Roman
* Andreas Abel andreas.a...@ifi.lmu.de [2013-05-20 13:26:05+0200]
Maybe instead of fiddling with the current Prelude (which might break
backwards compatibility), we should design a new prelude which is not
automatically loaded but contains roughly the current prelude (with
the list functions generalized to collections) plus the modern type
class stack: Functor, Applicative, Monad, Foldable, Traversable,
Monoid etc.
I am willing to write
{-# LANGUAGE NoImplicitPrelude #-}
import Base
if I get a decent, modern standard set of functions that could be
considered as the base vocabulary of modern Haskell programmers...
I just do not want to think about the democratic process involved in
this design...
Cheers,
Andreas
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Re: [Haskell-cafe] ANNOUNCE: new bridge! (prelude-prime)
HI, Am Donnerstag, den 23.05.2013, 12:38 +0400 schrieb Anton Kholomiov: I wish it was possible to use an extension CustomPrelude = Prelude.Prime In the cabal file as far as I know, GHC simply issues an implicit import Prelude without package qualifiers. So you can get what you want by not depending on base, but rather have prelude-prime re-export all modules from base plus its own Preldue. A more modular variant would be to have a package preludeless-base which re-exports all modules from base but the prelude. Then you can select which prelude you want simply by depending on preludeless-base (instead of base) plus a package (say prelude-prime) which exports a module named Prelude. If prelude-prime itself wants to use base, it can still use package-qualified imports. Or it could itself be based on preludeless-base. Greetings, Joachim -- Joachim nomeata Breitner Debian Developer nome...@debian.org | ICQ# 74513189 | GPG-Keyid: 4743206C JID: nome...@joachim-breitner.de | http://people.debian.org/~nomeata signature.asc Description: This is a digitally signed message part ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: new bridge! (prelude-prime)
On Thu, May 23, 2013 at 11:38 AM, Anton Kholomiov anton.kholom...@gmail.com wrote: I wish it was possible to use an extension CustomPrelude = Prelude.Prime In the cabal file I'm not necessarily opposed to this idea, but I'd like to point out that it can have a negative impact on readability of an individual module, since you can't tell which Prelude is being used. This is the same argument used for putting LANGUAGE pragmas in a modules instead of listing them in a cabal file. I think in the case of an alternate Prelude, the argument is stronger, since language extensions often don't change the meaning of code, but instead allow previously invalid code to be valid. Michael ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: new bridge! (prelude-prime)
On 23 May 2013 11:26, Joachim Breitner m...@joachim-breitner.de wrote: So you can get what you want by not depending on base, but rather have prelude-prime re-export all modules from base plus its own Preldue. How would you re-export all base's modules from the prelude-prime package? I didn't know this was already possible. Bas ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: new bridge! (prelude-prime)
Hi, Am Donnerstag, den 23.05.2013, 11:52 +0200 schrieb Bas van Dijk: On 23 May 2013 11:26, Joachim Breitner m...@joachim-breitner.de wrote: So you can get what you want by not depending on base, but rather have prelude-prime re-export all modules from base plus its own Preldue. How would you re-export all base's modules from the prelude-prime package? I didn't know this was already possible. manually... you create a .hs file for every module in base, which imports the module in base (using a package-qualified import), gives it a qualified name and puts that name in the export list. Greetings, Joachim -- Joachim nomeata Breitner Debian Developer nome...@debian.org | ICQ# 74513189 | GPG-Keyid: 4743206C JID: nome...@joachim-breitner.de | http://people.debian.org/~nomeata signature.asc Description: This is a digitally signed message part ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: new bridge! (prelude-prime)
On 23 May 2013 11:54, Joachim Breitner m...@joachim-breitner.de wrote: Hi, Am Donnerstag, den 23.05.2013, 11:52 +0200 schrieb Bas van Dijk: On 23 May 2013 11:26, Joachim Breitner m...@joachim-breitner.de wrote: So you can get what you want by not depending on base, but rather have prelude-prime re-export all modules from base plus its own Preldue. How would you re-export all base's modules from the prelude-prime package? I didn't know this was already possible. manually... you create a .hs file for every module in base, which imports the module in base (using a package-qualified import), gives it a qualified name and puts that name in the export list. I see. Thanks for the clarification. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] question about type constructors
Roman Cheplyaka wrote:
The rule of thumb is that you should never use IncoherentInstances.
The proper way to do it is:
data Person :: Gender - * where
Person :: String - Person b
Child
:: (PrettyPrint a, PrettyPrint b)
= String - Person a - Person b - Person c
Thanks a lot. Now I am using FlexibleContexts, and it works correctly (see
code below). I think I have understood the problem.
However, I have still one question. In the code below, I have added data
constructors Child2, Child3 (imagining a world where every people has
three children). The problem is that I am compelled to repeat the context
(PrettyPrint (Person a), PrettyPrint (Person b)) for each one of the
constructors. Is there any way to specify the context only once? I have
tried using forall, but without any success.
Thanks,
TP
-
{-# LANGUAGE GADTs #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE FlexibleContexts #-}
class PrettyPrint a where
prettify :: a - String
data Gender = Male | Female | Gender3 | Gender4
data Person :: Gender - * where
Person :: String - Person b
Child1 :: (PrettyPrint (Person a)
, PrettyPrint (Person b)
) = String - Person a - Person b - Person c
Child2 :: (PrettyPrint (Person a)
, PrettyPrint (Person b)
) = String - Person a - Person b - Person c
Child3 :: (PrettyPrint (Person a)
, PrettyPrint (Person b)
) = String - Person a - Person b - Person c
instance PrettyPrint (Person Male) where
prettify (Person name) = My name is ++ (show name)
++ and I am a male
prettify (Child1 name person1 person2) = My name is ++ (show name)
++ and my parents are: ++ (prettify person1) ++ ,
++ (prettify person2)
main = do
let a = Person Jim :: Person Male
let b = Person Joe :: Person Male
let c = Child1 Jack a b :: Person Male
print $ prettify a
print $ prettify b
print $ prettify c
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Re: [Haskell-cafe] question about type constructors
* TP paratribulati...@free.fr [2013-05-23 13:23:36+0200]
Roman Cheplyaka wrote:
The rule of thumb is that you should never use IncoherentInstances.
The proper way to do it is:
data Person :: Gender - * where
Person :: String - Person b
Child
:: (PrettyPrint a, PrettyPrint b)
= String - Person a - Person b - Person c
Thanks a lot. Now I am using FlexibleContexts, and it works correctly (see
code below). I think I have understood the problem.
However, I have still one question. In the code below, I have added data
constructors Child2, Child3 (imagining a world where every people has
three children). The problem is that I am compelled to repeat the context
(PrettyPrint (Person a), PrettyPrint (Person b)) for each one of the
constructors. Is there any way to specify the context only once? I have
tried using forall, but without any success.
No, because the type variables are independent across different
constructors. They are (implicitly) existentially quantified, which
becomes clearer if you rewrite your type as
data Person (c :: Gender)
= forall a b . (PrettyPrint (Person a), PrettyPrint (Person b))
= Child1 String (Person a) (Person b)
| forall a b . (PrettyPrint (Person a), PrettyPrint (Person b))
= Child2 String (Person a) (Person b)
| ...
What you can do is factor out the Child type as
data Child where
Child :: ( PrettyPrint (Person a)
, PrettyPrint (Person b)
) = String - Person a - Person b - Child
data Person a where
Child1 :: Child - Person c
Child2 :: Child - Person c
Child3 :: Child - Person c
-
{-# LANGUAGE GADTs #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE FlexibleContexts #-}
class PrettyPrint a where
prettify :: a - String
data Gender = Male | Female | Gender3 | Gender4
data Person :: Gender - * where
Person :: String - Person b
Child1 :: (PrettyPrint (Person a)
, PrettyPrint (Person b)
) = String - Person a - Person b - Person c
Child2 :: (PrettyPrint (Person a)
, PrettyPrint (Person b)
) = String - Person a - Person b - Person c
Child3 :: (PrettyPrint (Person a)
, PrettyPrint (Person b)
) = String - Person a - Person b - Person c
instance PrettyPrint (Person Male) where
prettify (Person name) = My name is ++ (show name)
++ and I am a male
prettify (Child1 name person1 person2) = My name is ++ (show name)
++ and my parents are: ++ (prettify person1) ++ ,
++ (prettify person2)
main = do
let a = Person Jim :: Person Male
let b = Person Joe :: Person Male
let c = Child1 Jack a b :: Person Male
print $ prettify a
print $ prettify b
print $ prettify c
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Re: [Haskell-cafe] ANNOUNCE: new bridge! (prelude-prime)
On Thu, May 23, 2013 at 3:07 AM, Roman Cheplyaka r...@ro-che.info wrote: Pull requests are welcome, but let's stick to widely agreed changes (like the Foldable/Traversable one). I think one of the reasons why other Preludes haven't been adopted is because they were too radical. * Andreas Abel andreas.a...@ifi.lmu.de [2013-05-20 13:26:05+0200] Maybe instead of fiddling with the current Prelude (which might break backwards compatibility), we should design a new prelude which is not automatically loaded but contains roughly the current prelude (with the list functions generalized to collections) plus the modern type class stack: Functor, Applicative, Monad, Foldable, Traversable, Monoid etc. Is this strategy adequate for attacking the issue of the type class stack, though? Defining, say, a new Monad class with the desired Functor constraint wouldn’t be of much use, as everything else on Hackage (and on the GHC libraries!) would still use the “real” Monad. I still see value in this package — a conservative extension to the Prelude would certainly come in handy. Thanks! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: new bridge! (prelude-prime)
* Manuel Gómez tar...@gmail.com [2013-05-23 08:33:15-0430] On Thu, May 23, 2013 at 3:07 AM, Roman Cheplyaka r...@ro-che.info wrote: Pull requests are welcome, but let's stick to widely agreed changes (like the Foldable/Traversable one). I think one of the reasons why other Preludes haven't been adopted is because they were too radical. * Andreas Abel andreas.a...@ifi.lmu.de [2013-05-20 13:26:05+0200] Maybe instead of fiddling with the current Prelude (which might break backwards compatibility), we should design a new prelude which is not automatically loaded but contains roughly the current prelude (with the list functions generalized to collections) plus the modern type class stack: Functor, Applicative, Monad, Foldable, Traversable, Monoid etc. Is this strategy adequate for attacking the issue of the type class stack, though? Defining, say, a new Monad class with the desired Functor constraint wouldn’t be of much use, as everything else on Hackage (and on the GHC libraries!) would still use the “real” Monad. No, it definitely isn't. Roman ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] HTML framework for web-ui
Vlatko Basic wrote: Hi Heinrich, Looks simple and interesting. I browsed the git, but not much docs yet. Just examples, or have I looked at wrong places? Thanks! Only examples and Haddock documentation so far, though the latter is extensive. I see that API is still under heavy design. When do you expect the API might stabilize? The current API probably won't change much until the first release, but I can't guarantee anything beyond that. It involves lots of aesthetic decisions. (BTW, examples in Readme do not work.) That would be one of the corners where it's not ready for public consumption yet. ;) Best regards, Heinrich Apfelmus -- http://apfelmus.nfshost.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to throw an error if using cabal-install version XYZ?
Great! Thanks. I adapted that trick and it worked fine:
https://github.com/rrnewton/haskell-lockfree-queue/blob/cb8ca1a5d8b4c02e45eeca54fbc66f0c58aeff56/AtomicPrimops/Setup.hs
On Wed, May 22, 2013 at 11:53 PM, Carter Schonwald
carter.schonw...@gmail.com wrote:
Hey Ryan,
I ran into a related issue, heres a a way you can do this safe IN the
cabal file (or at least you can modify my hack for your purposes)
heres a link to the workaround I did for making LLVM-hs work across =
1.17 and 1.17 cabal, but you could abuse it to make sure setup.hs barfs
on old cabal
https://github.com/bos/llvm/blob/master/base/Setup.hs#L89-L116
heres a quick one off gist that takes my trick and does something helpful
for you variant + makes sure the tool can't build otherwise
https://gist.github.com/cartazio/5632636
I just wrote a snippet that you can just add to your setup.hs and it
should guarantee the setup.hs will barf with a helpful error message on
cabal 1.17.0
On Wed, May 22, 2013 at 10:50 PM, Ryan Newton rrnew...@gmail.com wrote:
A cabal-install bug https://github.com/haskell/cabal/issues/1284 was
fixed recently that pertains to building C libraries with profiling.
As a result, I want a certain
packagehttp://hackage.haskell.org/package/atomic-primops-0.1.0.2to test if
cabal-install 0.17.0 is used, and throw a preemptive error.
Otherwise this package fails in weird ways at runtime (it's a nasty one).
I noticed with some surprise the following sequence:
* $ cabal --version*
* cabal-install version 1.16.0.2*
* using version 1.16.0.3 of the Cabal library*
* $ cabal clean*
* $ cabal install*
* $ cat dist/build/autogen/cabal_macros.h | grep VERSION_Cabal*
* #define VERSION_Cabal 1.17.0*
Alright, so that, in retrospect, makes sense. The version is which *my*
library is linked with is the relevant one, not the one cabal-install was
linked with [1].
So the natural next thought is to move the MIN_VERSION_Cabal test into
Setup.hs, and force cabal to use it by setting the build type to Custom.
But... I just learned from this ticket that the cabal macros are not
available in Setup.hs:
http://hackage.haskell.org/trac/hackage/ticket/326
Uh oh, what's left?
-Ryan
[1] P.S. Personally I'm now using a bash function like below, to force
the two versions to be the same:
function safe_cabal_install () {
VER=`cabal --version | tail -n1 | awk '{ print $3 }'`
cabal install --constraint=Cabal==$VER $*
}
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[Haskell-cafe] How not to force ghci debugger but still know the _result?
Hi, As the subject says, I'd like to use the GHCI debugger to inspect the results of some functions. I tried to set :break-points on these functions and :step through them, but unless I use :force I never get to see the result of these functions. Is it possible to somehow break when the result is evaluated? Please find below a log of my attempts to debug a small example, where during debugging none of the _result values is ever known/shown. Maarten Faddegon -- $ cat bla1.hs blabla:: [Int] - Int bla :: Int - Int papperlap :: Int - Int - Int bla x = x+x papperlap y x = ((y *) . bla) x blabla xs = foldl papperlap 0 xs $ ghci bla1.hs GHCi, version 7.6.3: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. [1 of 1] Compiling Main ( bla1.hs, interpreted ) Ok, modules loaded: Main. *Main :break blabla Breakpoint 0 activated at bla1.hs:7:1-36 *Main :break papperlap Breakpoint 1 activated at bla1.hs:6:1-31 *Main :break bla Breakpoint 2 activated at bla1.hs:5:1-19 *Main blabla [1,2,3] Stopped at bla1.hs:7:1-36 _result :: Int = _ [bla1.hs:7:1-36] *Main :step Stopped at bla1.hs:7:17-36 _result :: Int = _ xs :: [Int] = [1,2,3] [bla1.hs:7:17-36] *Main :step Stopped at bla1.hs:6:1-31 _result :: Int = _ [bla1.hs:6:1-31] *Main :step Stopped at bla1.hs:6:17-31 _result :: Int = _ x :: Int = 3 y :: Int = _ [bla1.hs:6:17-31] *Main :step Stopped at bla1.hs:6:1-31 _result :: Int = _ [bla1.hs:6:1-31] *Main :step Stopped at bla1.hs:6:17-31 _result :: Int = _ x :: Int = 2 y :: Int = _ [bla1.hs:6:17-31] *Main :step Stopped at bla1.hs:6:1-31 _result :: Int = _ [bla1.hs:6:1-31] *Main :step Stopped at bla1.hs:6:17-31 _result :: Int = _ x :: Int = 1 y :: Int = 0 [bla1.hs:6:17-31] *Main :step Stopped at bla1.hs:5:1-19 _result :: Int = _ [bla1.hs:5:1-19] *Main :step Stopped at bla1.hs:5:17-19 _result :: Int = _ x :: Int = 1 [bla1.hs:5:17-19] *Main :step Stopped at bla1.hs:5:1-19 _result :: Int = _ [bla1.hs:5:1-19] *Main :step Stopped at bla1.hs:5:17-19 _result :: Int = _ x :: Int = 2 [bla1.hs:5:17-19] *Main :step Stopped at bla1.hs:5:1-19 _result :: Int = _ [bla1.hs:5:1-19] *Main :step Stopped at bla1.hs:5:17-19 _result :: Int = _ x :: Int = 3 [bla1.hs:5:17-19] *Main :step 0 *Main ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Debugging embedded ruby interpreter
On 05/22/2013 11:36 PM, Simon Marechal wrote: Anyone has an idea on how I should approach this problem ? For future reference : I believe I have found the problem, and it was quite obvious ... When generating Ruby objects from Haskell, they are not referenced by anything in the interpreter. This means they will be collected everytime there is a GC run. I now manually enable / disable / start GC, and things seem to work. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
