[Haskell-cafe] Cabal fail
How do you make Cabal fail? Let me clarify. I built a package that uses a post-configure hook to do some settings detection. Under certain circumstances, it can fail. When this happens, the hook prints fatal error and quits. Unfortunately, I didn't actually /test/ whether it works. On further investigation, I discovered that the hook considers itself to have failed, but it doesn't bother actually telling Cabal about this. (!) So Cabal still thinks everything went fine. OK, so, let's the correct way to notify Cabal that we need to retry the configure step? I can't figure it out from the minimal documentation in Distribution.Simple. (I'm guessing I need to use a pre-configure hook, since by the time post-configure runs, the configure stage is presumably over...?) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Lazy lists vs generators
Yves Pare`s wrote: I cannot help smiling when I hear Java/C#/Python developers telling about the wondeful features of their languages ;) (- We have generators! We can _yield_ values! [1] - Yeah, so nice... We have simple lists... with lazy evaluation) Just for the record, lazy lists per se are sufficient only for simplest generators. Re-writing an accumulating traversal to accommodate suspension by hand is too ungainly and error prone. Still, if we just add exceptions (the Either monad), we can idiomatically write all the generator examples of Python or Icon, for example. If we do not need effects other than yielding or non-determinism, [Either e a], which is ErrorT e [] a, suffices. If we need IO or mutable state, we should replace [] with LogicT (which is the monad of lazy lists with effect). The following web page talks about lazy lists and generators http://okmij.org/ftp/continuations/generators.html in (perhaps too) great detail. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Class and Instance
Thanks for the feedback. I have two further questions 1. Why is it that the Containers class signature does not allow instances to be list of list? I suspect it is because x is a constructor. 2. How would I change the Containers class signature to allow instances to be lists of lists. Thanks, Pat -- x is a type constructor, not a type class Containers x y where insert :: y - x y - x y remove :: y - x y - x y whatsIn :: x y - [y] instance Containers [] Char where insert y [] = y:[] insert y m = y:m remove _ [] = [] remove x (y:ys) | x == y= remove x ys | otherwise = y : remove x ys whatsIn = id instance Containers [] Integer where insert y [] = y:[] insert y m = y:m remove _ [] = [] remove x (y:ys) | x == y= remove x ys | otherwise = y : remove x ys whatsIn = id -- cannot have containers of containers. -- instance Containers [] [] where -- container.hs:41:23: --`[]' is not applied to enough type arguments -- Expected kind `*', but `[]' has kind `* - *' -- In the instance declaration for `Containers [] []' -- Failed, modules loaded: none. This message has been scanned for content and viruses by the DIT Information Services E-Mail Scanning Service, and is believed to be clean. http://www.dit.ie ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Fixed points
On Fri, Jun 10, 2011 at 21:05, Alexander Solla alex.so...@gmail.com wrote: equivalenceClosure :: (Ord a) = Relation a - Relation a equivalenceClosure = fix (\f - reflexivity . symmetry . transitivity) If you want to learn about fix, this won't help you, but if you're just want the best way to calculate equivalence closures of relations, then it's probably equivalenceClosure = transitivity . symmetry . reflexivity assuming those are the transitive, symmetric and reflexive closure functions. You still need some kind of iteration to get the transitive closure. The algorithm I know of for that is Warshall's Algorithm, which is O(N^3) (possibly with a log N factor for pure data structures). --Max ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Lazy lists vs generators
Le 11/06/2011 11:06, o...@okmij.org a écrit : The following web page talks about lazy lists and generators http://okmij.org/ftp/continuations/generators.html in (perhaps too) great detail. Oleg, when you mention Icon, you might - perhaps - observe that Griswold didn't introduce the co-expressions (this is their terminology, not generators) out of the air, they have been present as the unevaluated expressions in Snobol4. Icon has been built upon the Snobol4 philosophy, although as language it was very different. Another remark about yield in Python. This is not just a non-deterministic return mechanism, but an expression, which yields a value also for the generator code. It becomes thus a reentrant co-procedure, which goes quite a mileage beyond the lazy list model. Jerzy Karczmarczuk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] How do you test a parser?
OK, so suppose you sit down and write a complicated string parser. Now how do you test that it works correctly? One way is to run the parser over a large corpus of real world samples. This has a number of problems: * If the parser is for a grammar you just invented yourself, presumably no real world corpus exists yet. * This tests that the most commonly used features work OK, but might not test whether more obscure features work right. * There's no really obvious way to check that what the parser returns is /correct/. You've got the input, but there's nothing to compare with. * This probably doesn't test whether the parser /fails/ for invalid input, since a real world corpus would presumably consist entirely of valid input. Most people's library of choice appears to be QuickCheck. But while it's not hard to have QuickCheck generate random strings and confirm that the returned parse tree (if any) doesn't violate any invariants, it's not so easy to check that the parse tree is actually what it should be. On top of that, depending on what the grammar is, the vast majority of random strings are probably just parse failures. Even if they aren't, there are probably specific constructs that are special-cased in the parser, which are very unlikely to appear by chance. (Things like keyword names, special combinations of punctuation, etc.) You can try to write your own text generator that constructs text more closely approximating what your parser is supposed to parse. But then how do you tell whether your generator is right? If you have a function that turns a parse tree back into text again, you can try verifying that a round-trip is the identity function. Except perhaps sometimes it isn't. Perhaps a given expression has more than one equivalent representation. A round-trip from string and back again is even less likely to be stable. So what's the best way to attack this problem? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Vi mode in ghci?
readline has keyboard shortcuts to change from emacs mode to vi and a separate to go back. Find out what they are and check if they work on haskeline, you got me wondering but i have no ghci access from here. Definitely easier than editing a config. Cheers, D. On Sat, Jun 11, 2011 at 00:08, Marc Weber marco-owe...@gmx.de wrote: You can also get vim-addon-async [1] and run ghci inside Vim. Then you can use all Vim goodness. [1]: requires client-server. Tested on Linux and Mac http://github.com/MarcWeber/vim-addon-async Marc Weber ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Class and Instance
The problem is that [] alone is not a concrete type - that is what the error is
saying, that [] needs to be applied to another type to yield a concrete type.
IE, you need a list of something, not just the idea of a list. That something
can be polymorphic, so the following works (note the [a]):
class Containers x y where
insert :: y - x y - x y
{-remove :: y - x y - x y
whatsIn :: x y - [y]-}
instance Containers [] [a] where
insert x y = x:y
On Jun 11, 2011, at 5:49 AM, Patrick Browne wrote:
Thanks for the feedback. I have two further questions
1. Why is it that the Containers class signature does not allow
instances to be list of list? I suspect it is because x is a constructor.
2. How would I change the Containers class signature to allow instances
to be lists of lists.
Thanks,
Pat
-- x is a type constructor, not a type
class Containers x y where
insert :: y - x y - x y
remove :: y - x y - x y
whatsIn :: x y - [y]
instance Containers [] Char where
insert y [] = y:[]
insert y m = y:m
remove _ [] = []
remove x (y:ys) | x == y= remove x ys
| otherwise = y : remove x ys
whatsIn = id
instance Containers [] Integer where
insert y [] = y:[]
insert y m = y:m
remove _ [] = []
remove x (y:ys) | x == y= remove x ys
| otherwise = y : remove x ys
whatsIn = id
-- cannot have containers of containers.
-- instance Containers [] [] where
-- container.hs:41:23:
--`[]' is not applied to enough type arguments
-- Expected kind `*', but `[]' has kind `* - *'
-- In the instance declaration for `Containers [] []'
-- Failed, modules loaded: none.
This message has been scanned for content and viruses by the DIT Information
Services E-Mail Scanning Service, and is believed to be clean.
http://www.dit.ie
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Re: [Haskell-cafe] How do you test a parser?
On 11/06/11 14:10, Andrew Coppin wrote: OK, so suppose you sit down and write a complicated string parser. Now how do you test that it works correctly? If you have a function that turns a parse tree back into text again, you can try verifying that a round-trip is the identity function. Except perhaps sometimes it isn't. Perhaps a given expression has more than one equivalent representation. A round-trip from string and back again is even less likely to be stable. So what's the best way to attack this problem? _ If your parse tree has a show instance (or better yet, a pretty-print function) then you can generate random parse trees, print them, and then show that the parse returns an equal tree. However if you want to have useful error messages or a wider range of representations than just those generated by show then you will need to write a QuickCheck variant on the show function that emits all these variations, which is likely to be rather more work. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] In ML books; functors only consume produce structures; whereas, functions CP values.
On Fri, Jun 10, 2011 at 07:53:58PM -0700, KC wrote: I've never seen such an easy description in Haskell books. Is there more going on with Haskell functors? Note that ML functors and Haskell functors are different things. ML functors are parameterized modules. Haskell functors are types which are instances of the Functor class. I think 'functor' is a bad name for the ML concept, but of course I'm somewhat biased. -Brent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] GHC7 build problem
Trying to compile GHC7 from source (as the ubuntu repository is still on GHC6), I came across the following error in the final phase: libraries/base/GHC/ST.lhs:78:1: You cannot SPECIALISE `forever' because its definition has no INLINE/INLINABLE pragma (or its defining module `Control.Monad' was compiled without -O) This was after: git clone [...] ./sync-all get perl boot ./configure make Is there some problem with trying to build GHC7 on a machine with GHC6, or did I just get the build procedure wrong (the last line of the error looks like a hint that I did). -- Scott Lawrence signature.asc Description: OpenPGP digital signature ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How do you test a parser?
Choices, choices. The first one is to use unit tests. Look at the grammar and make sure the obvious stuff fails or succeeds. a + b, a :+ b, etc. You can do this at the Haskell level with parser objects. Next you can write small samples to test things the unit tests did not. Compare the output to known results. There are numerous examples of this in the open source world you can either reuse or crib from. Personally I think QuickCheck is more work than it is worth here. On Jun 11, 2011, at 8:18, Paul Johnson p...@cogito.org.uk wrote: On 11/06/11 14:10, Andrew Coppin wrote: OK, so suppose you sit down and write a complicated string parser. Now how do you test that it works correctly? If you have a function that turns a parse tree back into text again, you can try verifying that a round-trip is the identity function. Except perhaps sometimes it isn't. Perhaps a given expression has more than one equivalent representation. A round-trip from string and back again is even less likely to be stable. So what's the best way to attack this problem? _ If your parse tree has a show instance (or better yet, a pretty-print function) then you can generate random parse trees, print them, and then show that the parse returns an equal tree. However if you want to have useful error messages or a wider range of representations than just those generated by show then you will need to write a QuickCheck variant on the show function that emits all these variations, which is likely to be rather more work. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How do you test a parser?
On Sat, Jun 11, 2011 at 10:06 AM, Sean Perry sha...@speakeasy.net wrote: Choices, choices. The first one is to use unit tests. Look at the grammar and make sure the obvious stuff fails or succeeds. a + b, a :+ b, etc. You can do this at the Haskell level with parser objects. Next you can write small samples to test things the unit tests did not. Compare the output to known results. There are numerous examples of this in the open source world you can either reuse or crib from. Don't just test the obvious things. If the parse tree is truly a tree, it is an initial algebra and amenable to case analysis as an initial algebra. In other words, you can do a proof by induction, just by checking all the base cases. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How do you test a parser?
On Sat, 11 Jun 2011 10:34:47 -0700 Alexander Solla alex.so...@gmail.com wrote: On Sat, Jun 11, 2011 at 10:06 AM, Sean Perry sha...@speakeasy.net wrote: Choices, choices. The first one is to use unit tests. Look at the grammar and make sure the obvious stuff fails or succeeds. a + b, a :+ b, etc. You can do this at the Haskell level with parser objects. Next you can write small samples to test things the unit tests did not. Compare the output to known results. There are numerous examples of this in the open source world you can either reuse or crib from. Don't just test the obvious things. If the parse tree is truly a tree, it is an initial algebra and amenable to case analysis as an initial algebra. In other words, you can do a proof by induction, just by checking all the base cases. Wouldn't also be reasonable for the test cases to be generated from the grammar automagically ? Seems much more useful than attempting to do it by hand. Seems like something which would have already been done, i.e. there's already a tool out there that does that ? Brian ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Announcing: hashtables-1.0.0.0
Hi all, I’m very pleased to announce today the release of the first version of hashtables, a Haskell library for fast mutable hash tables. The hashtables library contains three different mutable hash table implementations in the ST monad, as well as a type class abstracting out the functions common to each and a set of wrapper functions to use the hash tables in the IO monad. It's also substantially faster than Data.HashTable. For more information, including performance benchmarks vs. some of the other common Haskell associative datatypes, please see my blog post: http://gregorycollins.net/posts/2011/06/11/announcing-hashtables Although I’ve made substantial efforts to test this code prior to release, it is a version 1.0. Please send bug reports to the hashtables github issues page: https://github.com/gregorycollins/hashtables/issues. Thanks! G -- Gregory Collins g...@gregorycollins.net ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Announcing: hashtables-1.0.0.0
This is awesome, thanks Greg! I definitely have some code locally that could benefit from a better hashtable implementation. Michael On Sat, Jun 11, 2011 at 9:20 PM, Gregory Collins g...@gregorycollins.net wrote: Hi all, I’m very pleased to announce today the release of the first version of hashtables, a Haskell library for fast mutable hash tables. The hashtables library contains three different mutable hash table implementations in the ST monad, as well as a type class abstracting out the functions common to each and a set of wrapper functions to use the hash tables in the IO monad. It's also substantially faster than Data.HashTable. For more information, including performance benchmarks vs. some of the other common Haskell associative datatypes, please see my blog post: http://gregorycollins.net/posts/2011/06/11/announcing-hashtables Although I’ve made substantial efforts to test this code prior to release, it is a version 1.0. Please send bug reports to the hashtables github issues page: https://github.com/gregorycollins/hashtables/issues. Thanks! G -- Gregory Collins g...@gregorycollins.net ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How do you test a parser?
On Sat, Jun 11, 2011 at 7:10 AM, Andrew Coppin andrewcop...@btinternet.comwrote: If you have a function that turns a parse tree back into text again, you can try verifying that a round-trip is the identity function. Except perhaps sometimes it isn't. Perhaps a given expression has more than one equivalent representation. A round-trip from string and back again is even less likely to be stable. I find that this kind of testing works quite nicely in practice with QuickCheck, in the sense that it does a good job of finding bugs in both the unparser and the parser. It's possible, but unlikely, that you'll have a bug in the parser and a bug in the unparser that cancel one another out. Generate the ASTs; parse . unparse ought to be id, or perhaps t = t . parse . unparse for some simple transformation 't'. For example, if the parser annotates AST nodes with source positions, you may need 't' to strip them out. Kevin -- Kevin Charter kevin.char...@acm.org ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Fixed points
On Sat, Jun 11, 2011 at 3:19 AM, Max Rabkin max.rab...@gmail.com wrote: On Fri, Jun 10, 2011 at 21:05, Alexander Solla alex.so...@gmail.com wrote: equivalenceClosure :: (Ord a) = Relation a - Relation a equivalenceClosure = fix (\f - reflexivity . symmetry . transitivity) If you want to learn about fix, this won't help you, but if you're just want the best way to calculate equivalence closures of relations, then it's probably equivalenceClosure = transitivity . symmetry . reflexivity assuming those are the transitive, symmetric and reflexive closure functions. You still need some kind of iteration to get the transitive closure. The algorithm I know of for that is Warshall's Algorithm, which is O(N^3) (possibly with a log N factor for pure data structures). Cool, thanks for the suggestion. I was iterating all of them, since an iteration of transitive introduces new pairs to the relation (which are not guaranteed to have symmetric complements in my implementation). I suppose I can get away with not iterating reflexive, for something like an O(n) speed up for each iteration. This is a summary of the code. I haven't done order analysis on it. Relation is a newtype over a Set of pairs: -- | Iterate 'transitivity' to compute the transitive closure for a relation. transitivity :: (Ord a) = Relation a - Relation a transitivity (Relation set) = Relation $ (Set.fold _joinOn set) (set) -- | Compute the reflexive closure for a relation. In other words, take a set -- containing @(a,b)@, @(c,d)@, ... into one containing the originals and -- @(b,a)@, @(d,c)@, and so on. reflexivity :: (Ord a) = Relation a - Relation a reflexivity (Relation set) = Relation $ Set.unions [ set , (Set.map (\(x,_) - (x,x)) set) , (Set.map (\(_,y) - (y,y)) set) ] -- | Compute the symmetric closure for a relation. symmetry :: (Ord a) = Relation a - Relation a symmetry (Relation set) = Relation $ Set.union set (Set.map _symmetry set) _symmetry :: (a, a) - (a, a) _symmetry (a, b) = (b, a) _joinOn :: (Ord a) = (a,a) - Set (a,a) - Set (a,a) _joinOn (a,b) set = let fst' = Set.filter ((b ==) . fst) $ set snd' = Set.filter ((a ==) . snd) $ set in Set.unions [ set , Set.map (\(x,y) - (a,y)) fst' , Set.map (\(x,y) - (x,b)) snd' ] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] GHC7 build problem
Yes, the tree was broken for some time between yesterday and today, and you appear to have gotten unlikely. It should have been fixed now, so you should try again. Cheers, Edward Excerpts from Scott Lawrence's message of Sat Jun 11 12:44:18 -0400 2011: Trying to compile GHC7 from source (as the ubuntu repository is still on GHC6), I came across the following error in the final phase: libraries/base/GHC/ST.lhs:78:1: You cannot SPECIALISE `forever' because its definition has no INLINE/INLINABLE pragma (or its defining module `Control.Monad' was compiled without -O) This was after: git clone [...] ./sync-all get perl boot ./configure make Is there some problem with trying to build GHC7 on a machine with GHC6, or did I just get the build procedure wrong (the last line of the error looks like a hint that I did). ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Fixed points
On Sat, Jun 11, 2011 at 4:21 PM, Alexander Solla alex.so...@gmail.com wrote: _symmetry :: (a, a) - (a, a) _joinOn :: (Ord a) = (a,a) - Set (a,a) - Set (a,a) A note on style: we use variables starting with an underline _ just when they are not used. This kind of use is confusing. Cheers! -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Toy implementation of the STG machine
I'm looking for a simple implementation of the STG machine to do some experiments, preferably implemented in something with memory safety. Performance is totally secondary. I'm also not interested in garbage collection details, but I do want to look at the contents of the various stacks. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Toy implementation of the STG machine
Does Bernie Pope's http://www.haskell.org/haskellwiki/Ministg work for you? On 11 June 2011 21:19, Florian Weimer f...@deneb.enyo.de wrote: I'm looking for a simple implementation of the STG machine to do some experiments, preferably implemented in something with memory safety. Performance is totally secondary. I'm also not interested in garbage collection details, but I do want to look at the contents of the various stacks. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Push the envelope. Watch it bend. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Toy implementation of the STG machine
See also: * STG machine in Coq, http://www.cs.ox.ac.uk/files/3858/pirog-biernacki-hs10.pdf http://www.cs.ox.ac.uk/files/3858/pirog-biernacki-hs10.pdfAlso * ] Jon Mountjoy. The spineless tagless G-machine, naturally. 1998 ACM SIGPLAN International Conference on Functional Programming, SIGPLAN Notices, Vol. 34, No. 1, pages 163–173, Baltimore, Maryland, September 1998. ACM Press. On Sat, Jun 11, 2011 at 4:32 PM, Thomas Schilling nomin...@googlemail.comwrote: Does Bernie Pope's http://www.haskell.org/haskellwiki/Ministg work for you? On 11 June 2011 21:19, Florian Weimer f...@deneb.enyo.de wrote: I'm looking for a simple implementation of the STG machine to do some experiments, preferably implemented in something with memory safety. Performance is totally secondary. I'm also not interested in garbage collection details, but I do want to look at the contents of the various stacks. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Push the envelope. Watch it bend. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] GHC7 build problem
It appears the build is still broken. Sorry! Please stand by, or roll back the last set of commits. Edward Excerpts from Scott Lawrence's message of Sat Jun 11 12:44:18 -0400 2011: Trying to compile GHC7 from source (as the ubuntu repository is still on GHC6), I came across the following error in the final phase: libraries/base/GHC/ST.lhs:78:1: You cannot SPECIALISE `forever' because its definition has no INLINE/INLINABLE pragma (or its defining module `Control.Monad' was compiled without -O) This was after: git clone [...] ./sync-all get perl boot ./configure make Is there some problem with trying to build GHC7 on a machine with GHC6, or did I just get the build procedure wrong (the last line of the error looks like a hint that I did). ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Toy implementation of the STG machine
* Thomas Schilling: Does Bernie Pope's http://www.haskell.org/haskellwiki/Ministg work for you? MiniSTG might do it, I will definitely look at it. The source repository is gone, but there's still a tarball on Hackage. I had hoped for something more interactive, though. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Yesod: How safe are forms?
Hello fellow haskellers, how far does Yesod.Form protect you from invalid input? I'm particularly interested in what happens, when you submit invalid data to select fields or radio groups. Greets, Ertugrul -- nightmare = unsafePerformIO (getWrongWife = sex) http://ertes.de/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Yesod: How safe are forms?
For select/radio, the form will not validate. The same is true for most (all?) other fields. On Sun, Jun 12, 2011 at 2:35 AM, Ertugrul Soeylemez e...@ertes.de wrote: Hello fellow haskellers, how far does Yesod.Form protect you from invalid input? I'm particularly interested in what happens, when you submit invalid data to select fields or radio groups. Greets, Ertugrul -- nightmare = unsafePerformIO (getWrongWife = sex) http://ertes.de/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] GHC7 build problem
On 06/11/11 09:37 PM, Edward Z. Yang wrote: Yes, the tree was broken for some time between yesterday and today, and you appear to have gotten unlikely. It should have been fixed now, so you should try again. It's probably not fixed yet, since even last night build fails on opensolaris builder: http://darcs.haskell.org/ghcBuilder/builders/kgardas-opensolaris-x86-head/256/7.html Thanks, Karel ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
