Search Results

Search found 913 results on 37 pages for 'haskell multicore'.

Page 34/37 | < Previous Page | 30 31 32 33 34 35 36 37  | Next Page >

  • LinqToSql - Parallel - DataContext and Parallel

    - by Gregoire
    In .NET 4 and multicore environment, does the linq to sql datacontext object take advantage of the new parallels if we use DataLoadOptions.LoadWith? EDIT I know linq to sql does not parallelize ordinary queries. What I want to know is when we specify DataLoadOption.LoadWith, does it use parallelization to perform the match between each entity and its sub entities? Example: using(MyDataContext context = new MyDataContext()) { DataLaodOptions options =new DataLoadOptions(); options.LoadWith<Product>(p=>p.Category); return this.DataContext.Products.Where(p=>p.SomeCondition); } generates the following sql: Select Id,Name from Categories Select Id,Name, CategoryId from Products where p.SomeCondition when all the products are created, will we have a categories.ToArray(); Parallel.Foreach(products, p => { p.Category == categories.FirstOrDefault(c => c.Id == p.CategoryId); }); or categories.ToArray(); foreach(Product product in products) { product.Category = categories.FirstOrDefault(c => c.Id == product.CategoryId); } ?

    Read the article

  • My OpenCL kernel is slower on faster hardware.. But why?

    - by matdumsa
    Hi folks, As I was finishing coding my project for a multicore programming class I came up upon something really weird I wanted to discuss with you. We were asked to create any program that would show significant improvement in being programmed for a multi-core platform. I’ve decided to try and code something on the GPU to try out OpenCL. I’ve chosen the matrix convolution problem since I’m quite familiar with it (I’ve parallelized it before with open_mpi with great speedup for large images). So here it is, I select a large GIF file (2.5 MB) [2816X2112] and I run the sequential version (original code) and I get an average of 15.3 seconds. I then run the new OpenCL version I just wrote on my MBP integrated GeForce 9400M and I get timings of 1.26s in average.. So far so good, it’s a speedup of 12X!! But now I go in my energy saver panel to turn on the “Graphic Performance Mode” That mode turns off the GeForce 9400M and turns on the Geforce 9600M GT my system has. Apple says this card is twice as fast as the integrated one. Guess what, my timing using the kick-ass graphic card are 3.2 seconds in average… My 9600M GT seems to be more than two times slower than the 9400M.. For those of you that are OpenCL inclined, I copy all data to remote buffers before starting, so the actual computation doesn’t require roundtrip to main ram. Also, I let OpenCL determine the optimal local-worksize as I’ve read they’ve done a pretty good implementation at figuring that parameter out.. Anyone has a clue? edit: full source code with makefiles here http://www.mathieusavard.info/convolution.zip cd gimage make cd ../clconvolute make put a large input.gif in clconvolute and run it to see results

    Read the article

  • The best way to predict performance without actually porting the code?

    - by ardiyu07
    I believe there are people with the same experience with me, where he/she must give a (estimated) performance report of porting a program from sequential to parallel with some designated multicore hardwares, with a very few amount of time given. For instance, if a 10K LoC sequential program was given and executes on Intel i7-3770k (not vectorized) in 100 ms, how long would it take to run if one parallelizes the code to a Tesla C2075 with NVIDIA CUDA, given that all kinds of parallelizing optimization techniques were done? (but you're only given 2-4 days to report the performance? assume that you didn't know the algorithm at all. Or perhaps it'd be safer if we just assume that it's an impossible situation to finish the job) Therefore, I'm wondering, what most likely be the fastest way to give such performance report? Is it safe to calculate solely by the hardware's capability, such as GFLOPs peak and memory bandwidth rate? Is there a mathematical way to calculate it? If there is, please prove your method with the corresponding problem description and the algorithm, and also the target hardwares' specifications. Or perhaps there already exists such tool to (roughly) estimate code porting? (Please don't the answer: 'kill yourself is the fastest way.')

    Read the article

  • jQuery Autocomplete plug-in search configuration

    - by dev.e.loper
    I'm looking into using jQuery autocomplete plug-in to implement user lookup by first or last name. It looks like by default autocomplete looks up words by character sequence no matter its occurrence in a word. So if you have data such as: javascript, asp, haskell and you type in 'as' you will get all three. I would like it to at least match beginning of the word. So in above example you get only 'asp'. Is there a way to configure jQuery Autocomplete plug-in to do this? Ultimately it would be even better to match by beginning of first or last name like it is in Gmail.

    Read the article

  • Higher-order type constructors and functors in Ocaml

    - by sdcvvc
    Can the following polymorphic functions let id x = x;; let compose f g x = f (g x);; let rec fix f = f (fix f);; (*laziness aside*) be written for types/type constructors or modules/functors? I tried type 'x id = Id of 'x;; type 'f 'g 'x compose = Compose of ('f ('g 'x));; type 'f fix = Fix of ('f (Fix 'f));; for types but it doesn't work. Here's a Haskell version for types: data Id x = Id x data Compose f g x = Compose (f (g x)) data Fix f = Fix (f (Fix f)) -- examples: l = Compose [Just 'a'] :: Compose [] Maybe Char type Natural = Fix Maybe -- natural numbers are fixpoint of Maybe n = Fix (Just (Fix (Just (Fix Nothing)))) :: Natural -- n is 2 -- up to isomorphism composition of identity and f is f: iso :: Compose Id f x -> f x iso (Compose (Id a)) = a

    Read the article

  • What's the best name for a non-mutating "add" method on an immutable collection?

    - by Jon Skeet
    Sorry for the waffly title - if I could come up with a concise title, I wouldn't have to ask the question. Suppose I have an immutable list type. It has an operation Foo(x) which returns a new immutable list with the specified argument as an extra element at the end. So to build up a list of strings with values "Hello", "immutable", "world" you could write: var empty = new ImmutableList<string>(); var list1 = empty.Foo("Hello"); var list2 = list1.Foo("immutable"); var list3 = list2.Foo("word"); (This is C# code, and I'm most interested in a C# suggestion if you feel the language is important. It's not fundamentally a language question, but the idioms of the language may be important.) The important thing is that the existing lists are not altered by Foo - so empty.Count would still return 0. Another (more idiomatic) way of getting to the end result would be: var list = new ImmutableList<string>().Foo("Hello"); .Foo("immutable"); .Foo("word"); My question is: what's the best name for Foo? EDIT 3: As I reveal later on, the name of the type might not actually be ImmutableList<T>, which makes the position clear. Imagine instead that it's TestSuite and that it's immutable because the whole of the framework it's a part of is immutable... (End of edit 3) Options I've come up with so far: Add: common in .NET, but implies mutation of the original list Cons: I believe this is the normal name in functional languages, but meaningless to those without experience in such languages Plus: my favourite so far, it doesn't imply mutation to me. Apparently this is also used in Haskell but with slightly different expectations (a Haskell programmer might expect it to add two lists together rather than adding a single value to the other list). With: consistent with some other immutable conventions, but doesn't have quite the same "additionness" to it IMO. And: not very descriptive. Operator overload for + : I really don't like this much; I generally think operators should only be applied to lower level types. I'm willing to be persuaded though! The criteria I'm using for choosing are: Gives the correct impression of the result of the method call (i.e. that it's the original list with an extra element) Makes it as clear as possible that it doesn't mutate the existing list Sounds reasonable when chained together as in the second example above Please ask for more details if I'm not making myself clear enough... EDIT 1: Here's my reasoning for preferring Plus to Add. Consider these two lines of code: list.Add(foo); list.Plus(foo); In my view (and this is a personal thing) the latter is clearly buggy - it's like writing "x + 5;" as a statement on its own. The first line looks like it's okay, until you remember that it's immutable. In fact, the way that the plus operator on its own doesn't mutate its operands is another reason why Plus is my favourite. Without the slight ickiness of operator overloading, it still gives the same connotations, which include (for me) not mutating the operands (or method target in this case). EDIT 2: Reasons for not liking Add. Various answers are effectively: "Go with Add. That's what DateTime does, and String has Replace methods etc which don't make the immutability obvious." I agree - there's precedence here. However, I've seen plenty of people call DateTime.Add or String.Replace and expect mutation. There are loads of newsgroup questions (and probably SO ones if I dig around) which are answered by "You're ignoring the return value of String.Replace; strings are immutable, a new string gets returned." Now, I should reveal a subtlety to the question - the type might not actually be an immutable list, but a different immutable type. In particular, I'm working on a benchmarking framework where you add tests to a suite, and that creates a new suite. It might be obvious that: var list = new ImmutableList<string>(); list.Add("foo"); isn't going to accomplish anything, but it becomes a lot murkier when you change it to: var suite = new TestSuite<string, int>(); suite.Add(x => x.Length); That looks like it should be okay. Whereas this, to me, makes the mistake clearer: var suite = new TestSuite<string, int>(); suite.Plus(x => x.Length); That's just begging to be: var suite = new TestSuite<string, int>().Plus(x => x.Length); Ideally, I would like my users not to have to be told that the test suite is immutable. I want them to fall into the pit of success. This may not be possible, but I'd like to try. I apologise for over-simplifying the original question by talking only about an immutable list type. Not all collections are quite as self-descriptive as ImmutableList<T> :)

    Read the article

  • Nginx A/B testing

    - by Alex
    Hey, I'm trying to do A/B testing and I'm using Nginx fo this purpose. My Nginx config file looks like this: events { worker_connections 1024; } error_log /usr/local/experiments/apps/reddit_test/error.log notice; http { rewrite_log on; server { listen 8081; access_log /usr/local/experiments/apps/reddit_test/access.log combined; location / { if ($remote_addr ~ "[02468]$") { rewrite ^(.+)$ /experiment$1 last; } rewrite ^(.+)$ /main$1 last; } location /main { internal; proxy_pass http://www.reddit.com/r/lisp; } location /experiment { internal; proxy_pass http://www.reddit.com/r/haskell; } } } This is kind of working, but css and js files woon't load. Can anyone tell me what's wrong with this config file or what would be the right way to do it? Thanks, Alex

    Read the article

  • Rewriting UNIX cal(1)

    - by dharmatech
    Hello, Today I was testing out SRFI 19 and wrote a simple version of the UNIX cal(1) command. Here's a version in R6RS Scheme which runs in Ikarus and Ypsilon. A few example runs. Schemers: How would you write it? Use your favorite implementation. Ruby and Python: I'm guessing that y'all have elegant date and time libraries. I'm sure you can put the Schemers to shame. ;-) Let's see what ya got. I'd also like to see Haskell and golfed versions. Is there a Stack Overflow tag for re-implementations of UNIX commands? :-) Ed

    Read the article

  • Decision Tree code golf

    - by Chris Jester-Young
    In Google Code Jam 2009, Round 1B, there is a problem called Decision Tree that lent itself to rather creative solutions. Post your shortest solution; I'll update the Accepted Answer to the current shortest entry on a semi-frequent basis, assuming you didn't just create a new language just to solve this problem. :-P Current rankings: 107 Perl 121 PostScript (binary) 136 Ruby 154 Arc 160 PostScript (ASCII85) 170 PostScript 192 Python 199 Common Lisp 214 LilyPond 222 JavaScript 273 Scheme 280 R 312 Haskell 314 PHP 339 m4 346 C 406 Fortran 462 Java 476 Java (well, kind of) 718 OCaml 759 F# 1741 sed C++ not qualified for now

    Read the article

  • functional-style datatypes in Python

    - by Danny Roberts
    For anyone who's spent some time with sml, ocaml, haskell, etc. when you go back to using C, Python, Java, etc. you start to notice things you never knew were missing. I'm doing some stuff in Python and I realized what I really want is a functional-style datatype like (for example) datatype phoneme = Vowel of string | Consonant of voice * place * manner datatype voice = Voiced | Voiceless datatype place = Labial | Dental | Retroflex | Palatal | Velar | Glottal datatype manner = Stop | Affricate | Fricative | Nasal | Lateral type syllable = phoneme list Does anyone have a particular way that they like to simulate this in Python?

    Read the article

  • Including two signatures, both with a 'type t' [Standard ML]

    - by Andy Morris
    A contrived example: signature A = sig type t val x: t end signature B = sig type t val y: t end signature C = sig include A B end Obviously, this will cause complaints that type t occurs twice in C. But is there any way to express that I want the two ts to be equated, ending up with: signature C = sig type t val x: t val y: t end I tried all sorts of silly syntax like include B where type t = A.t, which unsurprisingly didn't work. Is there something I've forgotten to try? Also, I know that this would be simply answered by checking the language's syntax for anything obvious (or a lack of), but I couldn't find a complete grammar anywhere on the internet. (FWIW, the actual reason I'm trying to do this is Haskell-style monads and such, where a MonadPlus is just a mix of a Monad and an Alternative; at the moment I'm just repeating the contents of ALTERNATIVE in MONAD_PLUS, which strikes me as less than ideal.)

    Read the article

  • Install a vimball from the command line.

    - by Robert Massaioli
    As this post points out you can install Vimballs using the normal: vim somevimball.vba :so % :q But if you want to install a from the command line how do you do it? I ran a 'man vim' and it seems like the best "from source install" option was the '-S' option so I tried to install haskellmode with it: wget 'http://projects.haskell.org/haskellmode-vim/vimfiles/haskellmode-20090430.vba' vim -S haskellmode-20090430.vba and that failed to work. It gave me the following error: Error detected while processing function vimball#Vimball: line 10: (Vimball) The current file does not appear to be a Vimball! press ENTER or type command to continue It should be noted that using the first method I was able to successfully install the vimball. I have tried the second method on a few other vimballs and it has failed every time. Is there a way to install a vimball from the command line? It seems like a useful sort of task. Oh, and I am running the following version of vim: Version: 2:7.2.330-1ubuntu3 Thanks.

    Read the article

  • What kind of knowledge do you need to invent a new programming language?

    - by systempuntoout
    I just finished to read "Coders at works", a brilliant book by Peter Seibel with 15 interviews to some of the most interesting computer programmers alive today. Well, many of the interviewees have (co)invented\implemented a new programming language. Some examples: Joe Armstrong: Inventor of Erlang L. Peter Deutsch: implementer of Smalltalk-80 Brendan Eich: Inventor of JavaScript Dan Ingalls: Smalltalk implementor and designer Simon Peyton Jones: Coinventor of Haskell Guy Steele: Coinventor of Scheme Is out of any doubt that their minds have something special and unreachable, and i'm not crazy to think i will ever able to create a new language; i'm just interested in this topic. So, imagine a funny\grotesque scenario where your crazy boss one day will come to your desk to say "i want a new programming language with my name on it..take the time you need and do it", which is the right approach to studying this fascinating\intimidating\magic topic? What kind of knowledge do you need to model, design and implement a brand new programming language?

    Read the article

  • What kind of knowledge you need to invent a new programming language?

    - by systempuntoout
    I just finished to read "coders at works", a brilliant book by Peter Seibel with 15 interviews to some of the most interesting computer programmers alive today. Well, many of the interviewees have (co)invented\implemented a new programming language. For example: * Joe Armstrong: Inventor of Erlang * L. Peter Deutsch: implementer of Smalltalk-80 * Brendan Eich: Inventor of JavaScript * Dan Ingalls: Smalltalk implementor and designer * Simon Peyton Jones: Coinventor of Haskell * Guy Steele: Coinventor of Scheme Is out of any doubt that their minds have something special and unreachable, and i'm not crazy to think i will ever able to create a new language; i'm just interested in this topic. So, imagine a funny\grotesque scenario where your crazy boss one day will come to your desk to say "i want a new programming language with my name on it..take the time you need and do it", what will you start to study? What kind of knowledge do you need to model, design and implement a brand new programming language?

    Read the article

  • Are some data structures more suitable for functional programming than others?

    - by Rob Lachlan
    In Real World Haskell, there is a section titled "Life without arrays or hash tables" where the authors suggest that list and trees are preferred in functional programming, whereas an array or a hash table might be used instead in an imperative program. This makes sense, since it's much easier to reuse part of an (immutable) list or tree when creating a new one than to do so with an array. So my questions are: Are there really significantly different usage patterns for data structures between functional and imperative programming? If so, is this a problem? What if you really do need a hash table for some application? Do you simply swallow the extra expense incurred for modifications?

    Read the article

  • In what areas might the use of F# be more appropriate than C#?

    - by Peter McGrattan
    Over the last few years F# has evolved into one of Microsoft's fully supported languages employing many ideas incubated in OCaml, ML and Haskell. Over the last several years C# has extended it's general purpose features by introducing more and more functional language features: LINQ (list comprehension), Lamdas, Closures, Anonymous Delegates and more... Given C#'s adoption of these functional features and F#'s taxonomy as an impure functional language (it allows YOU to access framework libraries or change shared state when a function is called if you want to) there is a strong similarity between the two languages although each has it's own polar opposite primary emphasis. I'm interested in any successful models employing these two languages in your production polyglot programs and also the areas within production software (web apps, client apps, server apps) you have written in F# in the past year or so that you would previously have written in C#. EDIT: Edited based on feedback from close votes with the intent of reducing perceived ambiguity.

    Read the article

  • Why darcs instead of git?

    - by Ctrl Alt D-1337
    Using pure functional languages can have a lot of benefits over using impure imperatives but low level systems languages will generally allow you to achieve much greater performance especially when they are imperative because it allows you to specify the exact steps in how the cpu should compute the result. If there is ever list of tools where high performance is an absolute must then I would put source version controls systems right at the top of that list and git achieves this very well but performance is not it's only advantage over many other other types of version control systems anyway. The git team are handling the unsafe c code very well and I never worry about my type system or any other features of the language it is written in so why is it that there is a lot of haskell developers that must use darcs when they will only be using the finished product?

    Read the article

  • What's the best way to do literate programming in Python on Windows?

    - by JasonFruit
    I've been playing with various ways of doing literate programming in Python. I like noweb, but I have two main problems with it: first, it is hard to build on Windows, where I spend about half my development time; and second, it requires me to indent each chunk of code as it will be in the final program --- which I don't necessarily know when I write it. I don't want to use Leo, because I'm very attached to Emacs. Is there a good literate programming tool that: Runs on Windows Allows me to set the indentation of the chunks when they're used, not when they're written Still lets me work in Emacs Thanks! Correction: noweb does allow me to indent later --- I misread the paper I found on it. By default, notangle preserves whitespace and maintains indentation when expanding chunks. It can therefore be used with languages like Miranda and Haskell, in which indentation is significant That leaves me with only the "Runs on Windows" problem.

    Read the article

  • Common programming mistakes for Scala developers to avoid

    - by jelovirt
    In the spirit of Common programming mistakes for Java developers to avoid? Common programming mistakes for JavaScript developers to avoid? Common programming mistakes for .NET developers to avoid? Common programming mistakes for Haskell developers to avoid? Common programming mistakes for Python developers to avoid? Common Programming Mistakes for Ruby Developers to Avoid Common programming mistakes for PHP developers to avoid? what are some common mistakes made by Scala developers, and how can we avoid them? Also, as the biggest group of new Scala developers come from Java, what specific pitfalls they have to be aware of? For example, one often cited problem Java programmers moving to Scala make is use a procedural approach when a functional one would be more suitable in Scala. What other mistakes e.g. in API design newcomers should try to avoid.

    Read the article

  • Programming challenge: can you code a hello world program as a Palindrome?

    - by Assaf Lavie
    So the puzzle is to write a hello world program in your language of choice, where the program's source file as a string has to be a palindrome. To be clear, the output has to be exactly "Hello, World". Edit: Well, with comments it seems trivial (not that I thought of it myself of course [sigh].. hat tip to cobbal). So new rule: no comments. Edit: I feel kind of bad editing someone else's question to say this, but it will eliminate a lot of non-palindromes that keep popping up, and I'm tired of seeing the same simple mistake over and over. The following is NOT a palindrome: ()() The following IS a palindrome: ())( Brackets, parenthesis, and anything else that must match are a major barrier to palindrome-ing, yes, but that doesn't mean you can ignore them and post non-palindrome answers. Languages represented thus far: C, C++, Bash, elisp, C#, Perl, sh, Windows shell, Java, Common Lisp, Awk, Ruby, Brainfuck, Funge, Python, Machine Language, HQ9+, Assembly, TCL, J, php, Haskell, io, TeX, APL, Javascript, mIRC Script, Basic, Orc, Fortran, Unlambda, Pseudo-code, Befunge, CFML, Lua, INTERCAL, VBScript, HTML, sed, PostScript, GolfScript, REBOL, SQL

    Read the article

  • Very simple, terse and easy GUI programming “frameworks”

    - by jetxee
    Please list GUI programming libraries, toolkits, frameworks which allow to write GUI apps quickly. I mean in such a way, that GUI is described entirely in a human-readable (and human-writable) plain text file (code) code is terse (1 or 2 lines of code per widget/event pair), suitable for scripting structure and operation of the GUI is evident from the code (nesting of widgets and flow of events) details about how to build the GUI are hidden (things like mainloop, attaching event listeners, etc.) auto-layouts are supported (vboxes, hboxes, etc.) As answers suggest, this may be defined as declarative GUI programming, but it is not necessarily such. Any approach is OK if it works, is easy to use and terse. There are some GUI libraries/toolkits like this. They are listed below. Please extend the list if you see a qualifying toolkit missing. Indicate if the project is crossplatform, mature, active, and give an example if possible. Please use this wiki to discuss only Open Source projects. This is the list so far (in alphabetical order): Fudgets Fudgets is a Haskell library. Platform: Unix. Status: Experimental, but still maintained. An example: import Fudgets main = fudlogue (shellF "Hello" (labelF "Hello, world!" >+< quitButtonF)) GNUstep Renaissance Renaissance allows to describe GUI in simple XML. Platforms: OSX/GNUstep. Status: part of GNUstep. An example below: <window title="Example"> <vbox> <label font="big"> Click the button below to quit the application </label> <button title="Quit" action="terminate:"/> </vbox> </window> HTML HTML-based GUI (HTML + JS). Crossplatform, mature. Can be used entirely on the client side. Looking for a nice “helloworld” example. JavaFX JavaFX is usable for standalone (desktop) apps as well as for web applications. Not completely crossplatform, not yet completely open source. Status: 1.0 release. An example: Frame { content: Button { text: "Press Me" action: operation() { System.out.println("You pressed me"); } } visible: true } Screenshot is needed. Phooey Phooey is another Haskell library. Crossplatform (wxWidgets), HTML+JS backend planned. Mature and active. An example (a little more than a helloworld): ui1 :: UI () ui1 = title "Shopping List" $ do a <- title "apples" $ islider (0,10) 3 b <- title "bananas" $ islider (0,10) 7 title "total" $ showDisplay (liftA2 (+) a b) PythonCard PythonCard describes GUI in a Python dictionary. Crossplatform (wxWidgets). Some apps use it, but the project seems stalled. There is an active fork. I skip PythonCard example because it is too verbose for the contest. Shoes Shoes for Ruby. Platforms: Win/OSX/GTK+. Status: Young but active. A minimal app looks like this: Shoes.app { @push = button "Push me" @note = para "Nothing pushed so far" @push.click { @note.replace "Aha! Click!" } } Tcl/Tk Tcl/Tk. Crossplatform (its own widget set). Mature (probably even dated) and active. An example: #!/usr/bin/env wish button .hello -text "Hello, World!" -command { exit } pack .hello tkwait window . tekUI tekUI for Lua (and C). Platforms: X11, DirectFB. Status: Alpha (usable, but API still evolves). An example: #/usr/bin/env lua ui = require "tek.ui" ui.Application:new { Children = { ui.Window:new { Title = "Hello", Children = { ui.Text:new { Text = "_Hello, World!", Style = "button", Mode = "button", }, }, }, }, }:run() Treethon Treethon for Python. It describes GUI in a YAML file (Python in a YAML tree). Platform: GTK+. Status: work in proress. A simple app looks like this: _import: gtk view: gtk.Window() add: - view: gtk.Button('Hello World') on clicked: print view.get_label() Yet unnamed Python library by Richard Jones: This one is not released yet. The idea is to use Python context managers (with keyword) to structure GUI code. See Richard Jones' blog for details. with gui.vertical: text = gui.label('hello!') items = gui.selection(['one', 'two', 'three']) with gui.button('click me!'): def on_click(): text.value = items.value text.foreground = red XUL XUL + Javascript may be used to create stand-alone desktop apps with XULRunner as well as Mozilla extensions. Mature, open source, crossplatform. <?xml version="1.0"?> <?xml-stylesheet href="chrome://global/skin/" type="text/css"?> <window id="main" title="My App" width="300" height="300" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"> <caption label="Hello World"/> </window> Thank your for contributions!

    Read the article

  • Clojure: Testing every value from map operation for truth

    - by Ralph
    How can I test that every value in the collection returned by map is true? I am using the following: (defn test [f coll] (every? #(identity %) (map f coll))) with the anonymous function #(identity %), but I was wondering if there is a better way. I cannot use (apply and ...) because and is a macro. UPDATE: BTW, I am making my way through The Haskell Road to Logic, Maths, and Programming, by Kees Doets and Jan can Eijck, but doing the exercises in Clojure. It's a very interesting book.

    Read the article

  • Does MATLAB perform tail call optimization?

    - by Shea Levy
    I've recently learned Haskell, and am trying to carry the pure functional style over to my other code when possible. An important aspect of this is treating all variables as immutable, i.e. constants. In order to do so, many computations that would be implemented using loops in an imperative style have to be performed using recursion, which typically incurs a memory penalty due to the allocation a new stack frame for each function call. In the special case of a tail call (where the return value of a called function is immediately returned to the callee's caller), however, this penalty can be bypassed by a process called tail call optimization (in one method, this can be done by essentially replacing a call with a jmp after setting up the stack properly). Does MATLAB perform TCO by default, or is there a way to tell it to?

    Read the article

  • Learning Algorithms and Data Structures Fundamentals

    - by valya
    Can you recommend me a book or (better!) a site with many hard problems and exercises about data structures? I'm already answering project Euler questions, but these questions are about interesting, but uncommon algorithms. I hardly used even a simple tree. Maybe there is a site with exercises like: hey, you need to calculate this: ... . Do it using a tree. Now do it using a zipper. Upload your C (Haskell, Lisp, even Pascal or Fortress go) solution. Oh, your solution is so slow! Self-education is very hard then you trying to learn very common, fundamental things. How can I help myself with them without attending to courses or whatever?

    Read the article

  • What are the common programming mistakes in Python?

    - by Paul McGuire
    I was about to tag the recent question in which the OP accidentally shadowed the builtin operator module with his own local operator.py with the "common-mistakes" tag, and I saw that there are a number of interesting questions posted asking for common mistakes to avoid in Java, Ruby, Scala, Clojure, .Net, jQuery, Haskell, SQL, ColdFusion, and so on, but I didn't see any for Python. For the benefit of Python beginners, can we enumerate the common mistakes that we have all committed at one time or another, in the hopes of maybe steering a newbie or two clear of them? (In homage to "The Princess Bride", I call these the Classic Blunders.) If possible, a little supporting explanation on what the problem is, and the generally accepted resolution/workaround, so that the beginning Pythoner doesn't read your answer and say "ok, that's a mistake, how do I fix it?"

    Read the article

< Previous Page | 30 31 32 33 34 35 36 37  | Next Page >