Search Results

Search found 7689 results on 308 pages for 'template haskell'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 43/308 | < Previous Page | 39 40 41 42 43 44 45 46 47 48 49 50  | Next Page >

  • Different results when applying function to equal values

    - by Johannes Stiehler
    I'm just digging a bit into Haskell and I started by trying to compute the Phi-Coefficient of two words in a text. However, I ran into some very strange behaviour that I cannot explain. After stripping everything down, I ended up with this code to reproduce the problem: let sumTup = (sumTuples°concat) frequencyLists let sumFixTup = (138, 136, 17, 204) putStrLn (show ((138, 136, 17, 204) == sumTup)) putStrLn (show (phi sumTup)) putStrLn (show (phi sumFixTup)) This outputs: True NaN 0.4574206676616167 So although the sumTupand sumFixTup show as equal, they behave differently when passed to phi. The definition of phi is: phi (a, b, c, d) = let dividend = fromIntegral(a * d - b * c) divisor = sqrt(fromIntegral((a + b) * (c + d) * (a + c) * (b + d))) in dividend / divisor

    Read the article

  • Edit Comment Template in Netbeans PHP 6.8

    - by Shiro
    I would like to ask is there any way change the comment code template in Netbeans PHP 6.8 In eclipse, when I type /** ENTER , it would come out the comment template that I set in the setting, like this: /** * Apr 19, 2010 - Shiro * Description * * @return unknown_type */ function test() { } by Default Netbeans only will show the parameter in the function. /** * * @param <type> $order_No * @param <type> $array */ in Netbeans is there any possible I could found any customization about this, anyone know where is the setting for this?

    Read the article

  • perl dancer: passing database info to template

    - by Bubnoff
    Following Dancer tutorial here: http://search.cpan.org/dist/Dancer/lib/Dancer/Tutorial.pod I'm using my own sqlite3 database with this schema CREATE TABLE if not exists location (location_code TEXT PRIMARY KEY, name TEXT, stations INTEGER); CREATE TABLE if not exists session (id INTEGER PRIMARY KEY, date TEXT, sessions INTEGER, location_code TEXT, FOREIGN KEY(location_code) REFERENCES location(location_code)); My dancer code ( helloWorld.pm ) for the database: package helloWorld; use Dancer; use DBI; use File::Spec; use File::Slurp; use Template; our $VERSION = '0.1'; set 'template' => 'template_toolkit'; set 'logger' => 'console'; my $base_dir = qq(/home/automation/scripts/Area51/perl/dancer); # database crap sub connect_db { my $db = qw(/home/automation/scripts/Area51/perl/dancer/sessions.sqlite); my $dbh = DBI->connect("dbi:SQLite:dbname=$db", "", "", { RaiseError => 1, AutoCommit => 1 }); return $dbh; } sub init_db { my $db = connect_db(); my $file = qq($base_dir/schema.sql); my $schema = read_file($file); $db->do($schema) or die $db->errstr; } get '/' => sub { my $branch_code = qq(BPT); my $dbh = connect_db(); my $sql = q(SELECT * FROM session); my $sth = $dbh->prepare($sql) or die $dbh->errstr; $sth->execute or die $dbh->errstr; my $key_field = q(id); template 'show_entries.tt', { 'branch' => $branch_code, 'data' => $sth->fetchall_hashref($key_field), }; }; init_db(); true; Tried the example template on the site, doesn't work. <% FOREACH id IN data.keys.nsort %> <li>Date is: <% data.$id.sessions %> </li> <% END %> Produces page but with no data. How do I troubleshoot this as no clues come up in the console/cli? Thanks Bubnoff

    Read the article

  • Has anyone ever encountered a Monad Transformer in the wild?

    - by martingw
    In my area of business - back office IT for a financial institution - it is very common for a software component to carry a global configuration around, to log it's progress, to have some kind of error handling / computation short circuit... Things that can be modelled nicely by Reader-, Writer-, Maybe-monads and the like in Haskell and composed together with monad transformers. But there seem to some drawbacks: The concept behind monad transformers is quite tricky and hard to understand, monad transformers lead to very complex type signatures, and they inflict some performance penalty. So I'm wondering: Are monad transformers best practice when dealing with those common tasks mentioned above?

    Read the article

  • What exactly is a Monad?

    - by WeNeedAnswers
    Can someone please explain to me what a Monad is. I think I grasp Monoids and I grasp that they basically control the input of state into a system. I just look at the text in Haskell and glaze over. A simple example in python would be great. My current understanding is that a Monoid is a procedural piece of code that needs to be read from top to bottom in sequence with the output being the input for the function. I think that I may even got that wrong, but hey I am here to learn.

    Read the article

  • C++ non-member functions for nested template classes

    - by beldaz
    I have been writing several class templates that contain nested iterator classes, for which an equality comparison is required. As I believe is fairly typical, the comparison is performed with a non-member (and non-friend) operator== function. In doing so, my compiler (I'm using Mingw32 GCC 4.4 with flags -O3 -g -Wall) fails to find the function and I have run out of possible reasons. In the rather large block of code below there are three classes: a Base class, a Composed class that holds a Base object, and a Nested class identical to the Composed class except that it is nested within an Outer class. Non-member operator== functions are supplied for each. These classes are in templated and untemplated forms (in their own respective namespaces), with the latter equivalent to the former specialised for unsigned integers. In main, two identical objects for each class are compared. For the untemplated case there is no problem, but for the templated case the compiler fails to find operator==. What's going on? #include <iostream> namespace templated { template<typename T> class Base { T t_; public: explicit Base(const T& t) : t_(t) {} bool equal(const Base& x) const { return x.t_==t_; } }; template<typename T> bool operator==(const Base<T> &x, const Base<T> &y) { return x.equal(y); } template<typename T> class Composed { typedef Base<T> Base_; Base_ base_; public: explicit Composed(const T& t) : base_(t) {} bool equal(const Composed& x) const {return x.base_==base_;} }; template<typename T> bool operator==(const Composed<T> &x, const Composed<T> &y) { return x.equal(y); } template<typename T> class Outer { public: class Nested { typedef Base<T> Base_; Base_ base_; public: explicit Nested(const T& t) : base_(t) {} bool equal(const Nested& x) const {return x.base_==base_;} }; }; template<typename T> bool operator==(const typename Outer<T>::Nested &x, const typename Outer<T>::Nested &y) { return x.equal(y); } } // namespace templated namespace untemplated { class Base { unsigned int t_; public: explicit Base(const unsigned int& t) : t_(t) {} bool equal(const Base& x) const { return x.t_==t_; } }; bool operator==(const Base &x, const Base &y) { return x.equal(y); } class Composed { typedef Base Base_; Base_ base_; public: explicit Composed(const unsigned int& t) : base_(t) {} bool equal(const Composed& x) const {return x.base_==base_;} }; bool operator==(const Composed &x, const Composed &y) { return x.equal(y); } class Outer { public: class Nested { typedef Base Base_; Base_ base_; public: explicit Nested(const unsigned int& t) : base_(t) {} bool equal(const Nested& x) const {return x.base_==base_;} }; }; bool operator==(const Outer::Nested &x, const Outer::Nested &y) { return x.equal(y); } } // namespace untemplated int main() { using std::cout; unsigned int testVal=3; { // No templates first typedef untemplated::Base Base_t; Base_t a(testVal); Base_t b(testVal); cout << "a=b=" << testVal << "\n"; cout << "a==b ? " << (a==b ? "TRUE" : "FALSE") << "\n"; typedef untemplated::Composed Composed_t; Composed_t c(testVal); Composed_t d(testVal); cout << "c=d=" << testVal << "\n"; cout << "c==d ? " << (c==d ? "TRUE" : "FALSE") << "\n"; typedef untemplated::Outer::Nested Nested_t; Nested_t e(testVal); Nested_t f(testVal); cout << "e=f=" << testVal << "\n"; cout << "e==f ? " << (e==f ? "TRUE" : "FALSE") << "\n"; } { // Now with templates typedef templated::Base<unsigned int> Base_t; Base_t a(testVal); Base_t b(testVal); cout << "a=b=" << testVal << "\n"; cout << "a==b ? " << (a==b ? "TRUE" : "FALSE") << "\n"; typedef templated::Composed<unsigned int> Composed_t; Composed_t c(testVal); Composed_t d(testVal); cout << "c=d=" << testVal << "\n"; cout << "d==c ? " << (c==d ? "TRUE" : "FALSE") << "\n"; typedef templated::Outer<unsigned int>::Nested Nested_t; Nested_t e(testVal); Nested_t f(testVal); cout << "e=f=" << testVal << "\n"; cout << "e==f ? " << (e==f ? "TRUE" : "FALSE") << "\n"; // Above line causes compiler error: // error: no match for 'operator==' in 'e == f' } cout << std::endl; return 0; }

    Read the article

  • how to sort Gridview rows by a unbound Template column

    - by Nickson
    i want to sort my Gridview rows by a template column that is not bound to any database field. This template coulmn just has a label whose text i set in code depending on a value in a different column that is databound. So am stuck on how to set its sortExpression since its not linked to an column.

    Read the article

  • Retrieving the URL in Django template language

    - by Vernon
    In a Django template, how could I refer to the URL. I want to use it in static pages, to avoid having live links to the current page. Is there a way to do this with the Django template language or do I have to use JavaScript to do it? I would like to do something like {% if current_url == "/about/" %} About {% else %} <a href='/about/'>About</a> {% endif %} I'm using it for a simple blog, so there are no views written for those pages.

    Read the article

  • Haskell: grid in wxHaskell

    - by snorlaks
    Hello, Could someone explain me what this code does line by line ? how t ounderstand excactly first line with declaration ? what does it mean: [Prop (Grid ())]? thanks for help gridCtrl :: Window a -> [Prop (Grid ())] -> IO (Grid ()) gridCtrl parent props = feed2 props 0 $ initialWindow $ \id rect -> \props flags -> do g <- gridCreate parent id rect flags gridCreateGrid g 0 0 0 set g props return g

    Read the article

  • How does functional programming work?

    - by Headcrab
    I'm used to imperative/OO programming (know C, C++, Python, PHP, etc.). I wanted to get into functional programming but there are some things unclear to me. Take for example the languages F# and Haskell: How do you implement loops? By recursion? Eew. What about conditions? How can you get by without variables? I mean.. What do we have RAM for.. storing variables, right?

    Read the article

  • Format date in String Template email

    - by Gearóid
    I'm creating an email using String Template but when I print out a date, it prints out the full date (eg. Wed Apr 28 10:51:37 BST 2010). I'd like to print it out in the format dd/mm/yyyy but don't know how to format this in the .st file. I can't modify the date individually (using java's simpleDateFormatter) because I iterate over a collection of objects with dates. Is there a way to format the date in the .st email template?

    Read the article

  • XSLT modify node before applying template

    - by Grigory
    I have an XSL code that processes some nodes and if some condition is true, before doing apply-template select="." i need to modify current node(add and attribute). How can i add an attribute to the node before calling apply-template select=".", or it is not possible at all ?

    Read the article

  • UIHint can not resolve template in abstract models

    - by Reza Owliaei
    Assume an abstract model like this: public abstract class MyClass : BaseEntity { [UIHint("File")] public long? DocumentFileId { get; set; } } The problem is Cannot resolve template 'File', while there is File.cshtml in View editor templates. The point is, if I don't define MyClass as an abstract class, error will be solved. My question is, why editor template can not resolve in abstract classes, and how can I handle it?

    Read the article

  • How do I get Cabal to bypass my Windows proxy settings?

    - by Brent.Longborough
    When retrieving packages with Cabal, I frequently get errors with this message: user error (Codec.Compression.Zlib: premature end of compressed stream) It looks like Cabal is using my Windows Networking proxy settings (for Privoxy). From digging around Google, Cabal or its libraries appear to have (had) a problem in this area. Possible solutions I can see are: Turn off proxying while using Cabal (not very keen on this one); or Get a patch and start hacking. I'm hesitant to go down this path, as I'm a complete Haskell noob and I'm not yet comfortable with Darcs; or Give it the magic "can I haz no proxy" parameter. Hence the question.

    Read the article

  • C++ string template library

    - by Gopalakrishnan Subramani
    I want simple C++ string based template library to replace strings at runtime. For example, I will use string template = "My name is {{name}}"; At runtime, I want the name to be changed based on actual one. I found one example, www.stringtemplate.org but I little scared when its talks about antlr etc.

    Read the article

  • How to return number of rows in the template

    - by xRobot
    In my view I return all posts of one blog: posts = Post.objects.filter(blog=blog) and pass it to context. But.. How can I get the number of posts in the template ? This is my template: <h1>Number of posts: {{ ??? }} </h1> {% for post in posts %} {{ post.title }} {{ post.body }} {% endfor %}

    Read the article

  • ghc can't find my cabal installed packages

    - by nont
    I've installed ghc 6.12.3, and then the Haskell Platform. I'm trying to compile a test program: $ ghc test.hs test.hs:3:0: Failed to load interface for `Bindings': Use -v to see a list of the files searched for. so, naturally, I do cabal install Bindings Which works fine, and places the package in ~/.cabal/lib/bindings-0.1.2 The problem is, that when I go to compile again with ghc, it still doesn't find the package I've installed with cabal. compiling in verbose mode gives: ghc -v test.hs Using binary package database: /home/ludflu/ghc/lib/ghc-6.12.3/package.conf.d/package.cache Using binary package database: /home/ludflu/.ghc/x86_64-linux 6.12.3/package.conf.d/package.cache As suggested by another stackoverflow user, I tried: ghc-pkg describe rts > rts.pkg vi rts.pkg # add the /home/ludflu/.cabal/lib to `library-dirs` field ghc-pkg update rts.pkg But to no avail. How to I add the .cabal to the list of package directories to search? Thank you!

    Read the article

  • WPF button template alignment not setting correctly

    - by Dave Colwell
    Hi guys, I have created a button template consisting of a border and a content presenter. A style is then wrapped around this template and applied to a button, when this button is used it is not carrying the values for horizontal and vertical alignment. In the designer the allignments are showing and the button is in the correct place, but when i run the program the button appears to have horizontal alignment = left and vertical alignment = right. Any ideas?

    Read the article

  • Setting the AccountController in ASP.NET MVC 1.0 Template Not to Connect to SQL Server Express

    - by Maxim Z.
    I'm writing a website in ASP.NET MVC, using the ASP.NET MVC 1.0 template that was added to VS2008 for me by the ASP.NET MVC installer. The template automatically adds an AccountController, but its account methods tie into a SQL Server Express entity. I don't have Express installed here. How can I reconfigure it to use my SQL Server 2008 database and to store user info in some columns in a User table I've already created?

    Read the article

  • Lua template processor question

    - by PeterMmm
    I'm going to use that template engine LTP . There is not so much doc available. Now i'm stuck how to pass an environment into the render engine. I have basically this: local ltp = require("ltp.template") ltp.render(io.stdout, 1, "index.dhtm", false, {}, "<?lua", "?>", { total="2400" }) What data structure should be the last parameter (env_code), a string, a table with key=val ?

    Read the article

  • Analysis and Design for Functional Programming

    - by edalorzo
    How do you deal with analysis and design phases when you plan to develop a system using a functional programming language like Haskell? My background is in imperative/object-oriented programming languages, and therefore, I am used to use case analysis and the use of UML to document the design of program. But the thing is that UML is inherently related to the object-oriented way of doing software. And I am intrigued about what would be the best way to develop documentation and define software designs for a system that is going to be developed using functional programming. Would you still use use case analysis or perhaps structured analysis and design instead? How do software architects define the high-level design of the system so that developers follow it? What do you show to you clients or to new developers when you are supposed to present a design of the solution? How do you document a picture of the whole thing without having first to write it all? Is there anything comparable to UML in the functional world?

    Read the article

  • Why are difference lists more efficient than regular concatenation?

    - by Craig Innes
    I am currently working my way through the Learn you a haskell book online, and have come to a chapter where the author is explaining that some list concatenations can be ineffiecient: For example ((((a ++ b) ++ c) ++ d) ++ e) ++ f Is supposedly inefficient. The solution the author comes up with is to use 'difference lists' defined as newtype DiffList a = DiffList {getDiffList :: [a] -> [a] } instance Monoid (DiffList a) where mempty = DiffList (\xs -> [] ++ xs) (DiffList f) `mappend` (DiffList g) = DiffList (\xs -> f (g xs)) I am struggling to understand why DiffList is more computationally efficient than a simple concatenation in some cases. Could someone explain to me in simple terms why the above example is so inefficient, and in what way the DiffList solves this problem?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 39 40 41 42 43 44 45 46 47 48 49 50  | Next Page >