Re: [Haskell-cafe] ANN: unordered-containers - a new, faster hashing-based containers library
Hi Johan, this work is highly appreciated, thanks! * Johan Tibell johan.tib...@gmail.com [2011-02-18 17:38:51-0800] Hi all, I am delighted to announce the release of preview versions of two new packages: unordered-containers 0.1 Efficient hashing-based container types. http://hackage.haskell.org/package/unordered-containers hashable 1.1 Efficient hashing of common types. http://hackage.haskell.org/package/hashable These packages address a need for faster container types in Haskell, especially for string types like ByteString and Text. The package achieves better performance by using hashing and a Patricia trie (also known as a radix tree), instead of a balanced tree, in its implementation. -- Roman I. Cheplyaka :: http://ro-che.info/ Don't worry what people think, they don't do it very often. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] linear and dependent types
On Saturday 19 February 2011 1:11:23 AM Vasili I. Galchin wrote: BTW I was thinking of http://www.ats.org when I asked this question. Technically speaking, if one considers ATS to be dependently typed, then one might as well also consider GHC to be dependently typed (with the right extensions enabled). ATS would easily be a nicer language in that respect, though. -- Dan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Unable to get parallelism using `par`
On 17/02/2011 05:20 PM, Brandon Moore wrote: If you are using ghc 7.01, you need to compile with -rtsopts for the compiled program to parse +RTS options. That's true. I don't know of any way to provide a default value at compile time. That would be -with-rtsopts=-N2 (or whatever) http://www.haskell.org/ghc/docs/7.0-latest/html/users_guide/runtime-control.html#id3095435 But note that with GHC 7.x, the RTS *automatically* chooses the correct number of threads now. You no longer need to specify this manually (unless you specifically want to use some other number of threads for some reason). ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Unable to get parallelism using `par`
But note that with GHC 7.x, the RTS *automatically* chooses the correct number of threads now. You no longer need to specify this manually (unless you specifically want to use some other number of threads for some reason). Is that stated in the changelog or documentation somewhere? Do you still have to specify -threaded at compile-time? (Sorry for the dup Andrew, missed the 'reply all' button :\) -- Edward Amsden Undergraduate Computer Science Rochester Institute of Technology www.edwardamsden.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Update2
Ok so I wrote and update function update :: Node - [Node] It takes in a Node and returns a list of the Nodes that result from assigning True to an unassigned atom in one case and False in the other (ie. a case split). The list returned has two nodes as elements. One node contains the formula with an atom assigned True and the model updated with this assignment, and the other contains the formula with the atom assigned False and the model updated to show this. The lists of unassigned atoms of each node are also updated accordingly. This function makes use of an assign function to make the assignments. It also uses the chooseAtom function to select the literal to assign. update :: Node - [Node] update (formula, (atoms, model)) = [(assign (chooseAtom atoms, True) formula, (remove (chooseAtom atoms) atoms, ((chooseAtom atoms,True)) `insert` model)) , (assign (chooseAtom atoms, False) formula, (remove (chooseAtom atoms) atoms, ((chooseAtom atoms, False) `insert` model)) )] Now I have to do the same thing but this time I must implement a variable selection heuristic.this should replace the chooseAtom and I'm supposed to write a function update2 using it type Atom = String type Literal = (Bool,Atom) type Clause = [Literal] type Formula = [Clause] type Model = [(Atom, Bool)] type Node = (Formula, ([Atom], Model)) update2 :: Node - [Node] update2 = undefined So my question is how can I create a heurestic and to implement it into the update2 function ,that shoud behave identical to the update function ? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] skin info of haskellwiki
Hi, I would like to use a copy of the hawiki skin for http://ampersand.sf.org my projects mediawiki . I like the way the front page of www.haskell.org works. It uses a mediawiki skin, that is customized for the haskellwiki. However, it used to be http://www.haskell.org/haskellwiki/HaskellWiki:Site_software published , but I find broken links. Is there anyone that could help me out? thanks! -- View this message in context: http://haskell.1045720.n5.nabble.com/skin-info-of-haskellwiki-tp3392503p3392503.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell for children? Any experience?
Jason wrote: I remember when I was a kid, I wanted to be able to write things to disk so badly (I have no idea why), but to me that was what 'real' programming was all about. Actually, that reminds me of one of my motivations for programming when I first started programming (in N80-BASIC on an NEC PC-8001 mkII in Tokyo) in circa 1983. Back then, I first became enamored of the concept of programming upon seeing an Apple II-plus running a music program at a computer show (in Tokyo) in 1981 (just outside, and on the 38th floor of, the Sumitomo Sankaku Building in Shinjuku). There were a number of computers on display at that event, including Commodore 64s and other Apple II-series models, but the one that stood out the most was an Apple II-plus hooked up to an organ keyboard and a color monitor (many of the other computers were attached to monochrome displays). When I played music on the keyboard, vertical color bars appeared on the display, and the idea that an inanimate object could respond in real time to human actions with color and sound somehow felt extremely gratifying. Two years later, in 1983, when I borrowed an NEC PC-8001 mkII (from a computer store in Ginza) (the no longer existent Micom Base Ginza) and wrote a pocket book accounting program in N80-BASIC, I insisted on saving my data to disk. For some reason, the idea of being able to leave an external trace of my program's efforts on a physical medium, where the results would remain even after the computer was turned off, somehow made me feel as if the program had bestowed upon me, the user, the ability to make a difference, however minor, to the outside world as a direct result of programming the computer. For some reason, from my child's eye then (I was 15 years old at the time), this made me feel important. I agree that sound, animations, etc... are very sexy and if done right can increase their enthusiasm many fold, but it also has the ability to turn them off from the simple elegance of what first hooked their interest. So start simple and be attentive to what THEY enjoy and you will give them the most valuable programming knowledge of all: passion. While I understand this approach, when I was first exposed to computer science in college, I thought that, too often, issues of input and output and storage and graphics and sound were ignored in introductory classes. Although such concepts may be trivial from a theoretical viewpoint, from the eye of a child (or even beginning computer science student), they are some of the aspects that can make programming exciting: the ability to cause the computer to reach to human input in real time with color graphics and sound, and to leave a trace of the interaction in the outside world for a future session even after the computer has been turned off. One of the reasons that I started reading, for example, Paul Hudak's _The Haskell School of Expression_ was the author's emphasis on multimedia. One of the reasons that I started programming with N80-BASIC in 1983 was the language's support for color graphics and (albeit elementary) sound. -- Benjamin L. Russell Best of luck and keep us up to date on your blog/reddit posts! -- Jason M. Knight ___ 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] Haskell for children? Any experience?
Chris Smith wrote: Manuel, Wow, that gloss package is really cool, and exactly the sort of thing I was looking for. As I've said before, I don't think I can prevent this from becoming about how to write games eventually. Gloss looks like provides a nice way to approach graphics programming in a simple functional style, with a clean interface consisting entirely of high-level ideas, and which easily switches over to the game interface later. Awesome! Actually, I've been wishing for a high-level way of creating an interactive three-dimensional virtual world in Haskell that doesn't require explicit knowledge of linear algebra. Ideally, I'm looking for a Haskell way of creating a functional counterpart to, say, Open Cobalt (see http://www.opencobalt.org/) that is high-level-enough not to require explicit manipulation of row and column vectors. One of the main problems, however, is the lack of reflection. Ideally, I would like the project to be able to modify its own framework in real time, so that, for example, within the virtual world, users would be able to create portals to other virtual worlds, and then write code while the project was running to change the configuration without restarting the project. Then users would be able to write code in the functional style to change the virtual environment _in situ._ Eventually, the project could be used as the egg for a much larger project that would allow users to work, study, shop, pay bills, and trade, all within a virtual city. Users could program in Haskell in a virtual classroom, write code in real-time to reconfigure the behavior of the classroom, then work on-line (say, by doing translation work) to earn a living, then pay rent or online bills without leaving the virtual world, and, when bored, form parties or alliances with other avatars to complete quests, craft items, or battle mon^H^H^H bugs to earn experience points, blurring the borders between work/study and play. -- Benjamin L. Russell Thank you so much for pointing it out. -- Chris Smith ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Update2
1. Atom: The Atom is the datatype used to describe Atomic Sentences or propositions. These are basically represented as a string. 2. Literal: Literals correspond to either atoms or negations of atoms. In this implementation each literal is represented as a pair consisting of a boolean value, indicating the polarity of the Atom, and the actual Atom. Thus, the literal ‘P’ is represented as (True,P) whereas its negation ‘-P’ as (False,P). 2 3. Clause: A Clause is a disjunction of literals, for example PvQvRv-S. In this implementation this is represented as a list of Literals. So the last clause would be [(True,P), (True,Q), (True,R),(False,S)]. 4. Formula: A Formula is a conjunction of clauses, for example (P vQ)^(RvP v-Q)^(-P v-R). This is the CNF form of a propositional formula. In this implementation this is represented as a list of Clauses, so it is a list of lists of Literals. Our above example formula would be [[(True,P), (True,Q)], [(True,R), (True,P), (False,Q)], [(False, P), (False,P)]]. 5. Model: A (partial) Model is a (partial) assignment of truth values to the Atoms in a Formula. In this implementation this is a list of (Atom, Bool) pairs, ie. the Atoms with their assignments. So in the above example of type Formula if we assigned true to P and false to Q then our model would be [(P, True),(Q, False)] -- View this message in context: http://haskell.1045720.n5.nabble.com/Update2-tp3392490p3392589.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: unordered-containers - a new, faster hashing-based containers library
A couple thoughts: size takes O(n). That's just depressing. Really. Do you think union, intersection, etc. could be supported? Louis Wasserman wasserman.lo...@gmail.com http://profiles.google.com/wasserman.louis ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: unordered-containers - a new, faster hashing-based containers library
On Sat, Feb 19, 2011 at 11:58 AM, Louis Wasserman wasserman.lo...@gmail.com wrote: A couple thoughts: size takes O(n). That's just depressing. Really. This applies to all the container types. We could support O(1) size at the cost of slowing down e.g lookup, insert, and delete a little bit. I haven't measure how much yet. Would it be worth it? Do you think union, intersection, etc. could be supported? Louis Wasserman Definitely. I plan to add most of the Data.Map API. We cannot support the ordered operations (such as min) but we should be able to support the rest. Johan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: unordered-containers - a new, faster hashing-based containers library
On Sat, Feb 19, 2011 at 3:04 PM, Johan Tibell johan.tib...@gmail.com wrote: On Sat, Feb 19, 2011 at 11:58 AM, Louis Wasserman wasserman.lo...@gmail.com wrote: A couple thoughts: size takes O(n). That's just depressing. Really. This applies to all the container types. We could support O(1) size at the cost of slowing down e.g lookup, insert, and delete a little bit. I haven't measure how much yet. Would it be worth it? Getting a bit picky, but for the record, Data.Map and Data.Sequence provide O(1) size, and Data.HashTable I believe stores the information but doesn't expose it from its tiny API. That's not an argument either way for what a HashMap should do, however :-) Cheers, Sterl. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: unordered-containers - a new, faster hashing-based containers library
On 2/18/11 8:38 PM, Johan Tibell wrote: Hi all, I am delighted to announce the release of preview versions of two new packages: unordered-containers 0.1 Efficient hashing-based container types. http://hackage.haskell.org/package/unordered-containers How does, or will, this package differ from Milan Straka's http://hackage.haskell.org/package/hashmap ? -- Live well, ~wren ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: unordered-containers - a new, faster hashing-based containers library
On Sat, Feb 19, 2011 at 4:27 PM, Sterling Clover s.clo...@gmail.com wrote: Getting a bit picky, but for the record, Data.Map and Data.Sequence provide O(1) size, and Data.HashTable I believe stores the information but doesn't expose it from its tiny API. That's not an argument either way for what a HashMap should do, however :-) We could support O(1) size. I have a design that doesn't waste one word per node to store the size. I'll look into it as soon as I have time. Johan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: unordered-containers - a new, faster hashing-based containers library
On Sat, Feb 19, 2011 at 4:49 PM, wren ng thornton w...@freegeek.org wrote: How does, or will, this package differ from Milan Straka's http://hackage.haskell.org/package/hashmap ? It's a continuation of that work. The unordered-containers implementation is more space efficient and a bit faster. Milan also uses a Patricia trie in his implementation. I plan to switch to a hash-array mapped trie (HAMT) in the future. It's about 25% faster for lookups but at the moment quite a bit slower for inserts. Once we got some new faster array copy primops in GHC we can hopefully improve the insert time a lot. A HAMT also has much lower space overhead per entry. Johan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: unordered-containers - a new, faster hashing-based containers library
On Sat, Feb 19, 2011 at 7:27 PM, Sterling Clover s.clo...@gmail.com wrote: On Sat, Feb 19, 2011 at 3:04 PM, Johan Tibell johan.tib...@gmail.com wrote: On Sat, Feb 19, 2011 at 11:58 AM, Louis Wasserman wasserman.lo...@gmail.com wrote: A couple thoughts: size takes O(n). That's just depressing. Really. This applies to all the container types. We could support O(1) size at the cost of slowing down e.g lookup, insert, and delete a little bit. I haven't measure how much yet. Would it be worth it? Getting a bit picky, but for the record, Data.Map and Data.Sequence provide O(1) size, and Data.HashTable I believe stores the information but doesn't expose it from its tiny API. That's not an argument either way for what a HashMap should do, however :-) NB: Data.IntMap, which Data.HashMap is based on, actually only provides O(n) size. -Edward ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: unordered-containers - a new, faster hashing-based containers library
I'd like to complain about that, too ;) Louis Wasserman wasserman.lo...@gmail.com http://profiles.google.com/wasserman.louis On Sat, Feb 19, 2011 at 9:02 PM, Edward Kmett ekm...@gmail.com wrote: On Sat, Feb 19, 2011 at 7:27 PM, Sterling Clover s.clo...@gmail.comwrote: On Sat, Feb 19, 2011 at 3:04 PM, Johan Tibell johan.tib...@gmail.com wrote: On Sat, Feb 19, 2011 at 11:58 AM, Louis Wasserman wasserman.lo...@gmail.com wrote: A couple thoughts: size takes O(n). That's just depressing. Really. This applies to all the container types. We could support O(1) size at the cost of slowing down e.g lookup, insert, and delete a little bit. I haven't measure how much yet. Would it be worth it? Getting a bit picky, but for the record, Data.Map and Data.Sequence provide O(1) size, and Data.HashTable I believe stores the information but doesn't expose it from its tiny API. That's not an argument either way for what a HashMap should do, however :-) NB: Data.IntMap, which Data.HashMap is based on, actually only provides O(n) size. -Edward ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
