Search Results

Search found 5189 results on 208 pages for 'foo wei tau'.

Page 54/208 | < Previous Page | 50 51 52 53 54 55 56 57 58 59 60 61  | Next Page >

• Is it good to subclass a class only to separate some functional parts?

  - by prostynick

  Suppose we have abstract class A (all examples in C#) public abstract class A { private Foo foo; public A() { } public void DoSomethingUsingFoo() { //stuff } public void DoSomethingElseUsingFoo() { //stuff } //a lot of other stuff... } But we are able to split it into two classes A and B: public abstract class A { public A() { } //a lot of stuff... } public abstract class B : A { private Foo foo; public B() : base() { } public void DoSomethingUsingFoo() { //stuff } public void DoSomethingElseUsingFoo() { //stuff } //nothing else or just some overrides of A stuff } That's good, but we are 99.99% sure, that no one will ever subclass A, because functionality in B is very important. Is it still good to have two separate classes only to split some code into two parts and to separate functional elements?

  Read the article

• @import doesn't work when suffix isn't .css?

  - by wamp

  This works: @import "foo.css" This fails: @import "foo.cssabc" Any reason for this?

  Read the article

• How is a functional programming-based javascript app laid out?

  - by user321521

  I've been working with node.js for awhile on a chat app (I know, very original, but I figured it'd be a good learning project). Underscore.js provides a lot of functional programming concepts which look interesting, so I'd like to understand how a functional program in javascript would be setup. From my understanding of functional programming (which may be wrong), the whole idea is to avoid side effects, which are basically having a function which updates another variable outside of the function so something like var external; function foo() { external = 'bar'; } foo(); would be creating a side effect, correct? So as a general rule, you want to avoid disturbing variables in the global scope. Ok, so how does that work when you're dealing with objects and what not? For example, a lot of times, I'll have a constructor and an init method that initializes the object, like so: var Foo = function(initVars) { this.init(initVars); } Foo.prototype.init = function(initVars) { this.bar1 = initVars['bar1']; this.bar2 = initVars['bar2']; //.... } var myFoo = new Foo({'bar1': '1', 'bar2': '2'}); So my init method is intentionally causing side effects, but what would be a functional way to handle the same sort of situation? Also, if anyone could point me to either a python or javascript source code of a program that tries to be as functional as possible, that would also be much appreciated. I feel like I'm close to "getting it", but I'm just not quite there. Mainly I'm interested in how functional programming works with traditional OOP classes concept (or does away with it for something different if that's the case).

  Read the article

• Where to put conditionals in ANSI-syntax SQL queries

  - by RenderIn

  What's the difference between these two queries? I've been resistant to jumping on the ANSI-syntax bandwagon because I have not been able to unravel various syntactical ambiguities. Is 1) returning the product of the join and only then filtering out those joined records which have weight = 500? And is 2) filtering out those prior to the join? Is 2 bad syntax? Why might I use that? 1: SELECT SOMETHING FROM FOO INNER JOIN BAR ON FOO.NAME = BAR.NAME WHERE BAR.WEIGHT < 500 2: SELECT SOMETHING FROM FOO INNER JOIN BAR ON FOO.NAME = BAR.NAME AND BAR.WEIGHT < 500

  Read the article

• Android: making a custom ListView independent of adapters ?

  - by wei

  I am adding a local database as a cache to a remote web service in my android application to answer queries. I used ArrayAdapters before for list views to display the results from the web service. Now with a database cache, the result could be either a Cursor(from database) or a List(from web), which means the adapter can be CursorAdapter or ArrayAdapter too. Creating two adapters for one query doesn't seem to be a good idea. So I am wondering what would be the best way to refactor my current code to add this database feature? Thanks,

  Read the article

• Differentiate generic methods by type parameters only using reflection?

  - by Brian Vallelunga

  I'm trying to use reflection to get a specific MethodInfo of a class, but am unsure how to differentiate between the two following methods: public class Test { public IBar<T1> Foo<T1>(); public IBar<T1, T2> Foo<T1, T2>(); } How can I get a reference to the different Foo methods, assuming I know the number of type parameters? Just calling typeof(Test).GetMethod("Foo") will throw an exception that the method name is ambiguous and there aren't a differing number of parameters to check.

  Read the article

• Why Does Private Access Remain Non-Private in .NET Within a Class?

  - by AMissico

  While cleaning some code today written by someone else, I changed the access modifier from Public to Private on a class variable/member/field. I expected a long list of compiler errors that I use to "refactor/rework/review" the code that used this variable. Imagine my surprise when I didn't get any errors. After reviewing, it turns out that another instance of the Class can access the private members of another instance declared within the Class. Totally unexcepted. Is this normal? I been coding in .NET since the beginning and never ran into this issue, nor read about it. I may have stumbled onto it before, but only "vaguely noticed" and move on. Can anyone explain this behavoir to me? Am I doing something wrong? I found this behavior in both C# and VB.NET. The code seems to take advantage of the ability to access private variables. Sincerely, Totally Confused Class Foo Private _int As Integer Private _foo As Foo Private _jack As Jack Private _fred As Fred Public Sub SetPrivate() _foo = New Foo _foo._int = 3 'TOTALLY UNEXPECTED _jack = New Jack '_jack._int = 3 'expected compile error because Foo doesn't know Jack _fred = New Fred '_fred._int = 3 'expected compile error because Fred hides from Foo End Sub Private Class Fred Private _int As Integer End Class End Class Class Jack Private _int As Integer End Class

  Read the article

• string parsing and substring in c

  - by Josh

  I'm trying to parse the string below in a good way so I can get the sub-string stringI-wantToGet: const char *str = "Hello \"FOO stringI-wantToGet BAR some other extra text"; str will vary in length but always same pattern - FOO and BAR What I had in mind was something like: const char *str = "Hello \"FOO stringI-wantToGet BAR some other extra text"; char *probe, *pointer; probe = str; while(probe != '\n'){ if(probe = strstr("\"FOO")!=NULL) probe++ else probe = ""; // Nulterm part if(pointer = strchr(probe, ' ')!=NULL) pointer = '\0'; // not sure here, I was planning to separate it with \0's } Any help will be appreciate it.

  Read the article

• How to set a __str__ method for all ctype Structure classes?

  - by Reuben Thomas

  [Since asking this question, I've found: http://www.cs.unc.edu/~gb/blog/2007/02/11/ctypes-tricks/ which gives a good answer.] I just wrote a __str__ method for a ctype-generated Structure class 'foo' thus: def foo_to_str(self): s = [] for i in foo._fields_: s.append('{}: {}'.format(i[0], foo.\_\_getattribute__(self, i[0]))) return '\n'.join(s) foo.\_\_str__ = foo_to_str But this is a fairly natural way to produce a __str__ method for any Structure class. How can I add this method directly to the Structure class, so that all Structure classes generated by ctypes get it? (I am using the h2xml and xml2py scripts to auto-generate ctypes code, and this offers no obvious way to change the names of the classes output, so simply subclassing Structure, Union &c. and adding my __str__ method there would involve post-processing the output of xml2py.)

  Read the article

• jQueryUI: how can I custom-format the Autocomplete plug-in results?

  - by dev.e.loper

  I'm using jQuery UI Autocomplete plug-in. Is there a way to highlight search character sequence in drop-down results? For example, if I have data: "foo bar" it and I search for "foo" I get "foo bar" in drop down.

  Read the article

• Java init method

  - by Johan Sjöberg

  What's a good way to make sure an init method is invoked in java? The alternatives I see are Don't test it, let the method fail by itself, likely by a NullPointerException Test if method was initialized or throw public void foo() { if (!inited) { throw new IllegalArgumentException("not initalized"); } ... } Delagate public void foo() { if (!inited) { throw new IllegalArgumentException("not initalized"); } fooInternal(); } private void fooInternal(){ ... }; Always init, and make init a noop otherwise public void foo() { init(); ... } public void init() { if(!inited) { ... } } Silently init public void foo() { if (!inited) { init(); } ... } Most of these approaches are very verbose and decreases overall readability.

  Read the article

• Type patterns in Haskell

  - by finnsson

  I'm trying to compile a simple example of generic classes / type patterns (see http://www.haskell.org/ghc/docs/latest/html/users_guide/generic-classes.html) in Haskell but it won't compile. Any ideas about what's wrong with the code would be helpful. According to the documentation there should be a module Generics with the data types Unit, :*:, and :+: but ghc (6.12.1) complaints about Not in scope: data constructor 'Unit' etc. It seems like there's a package instant-generics with the data types :*:, :+: and U but when I import that module (instead of Generics) I get the error Illegal type pattern in the generic bindings {myPrint _ = ""} The complete source code is import Generics.Instant class MyPrint a where myPrint :: a -> String myPrint {| U |} _ = "" myPrint {| a :*: b |} (x :*: y) = "" (show x) ++ ":*:" ++ (show y) myPrint {| a :+: b |} _ = "" data Foo = Foo String instance MyPrint a => MyPrint a main = myPrint $ Foo "hi" and I compile it using ghc --make Foo.hs -fglasgow-exts -XGenerics -XUndecidableInstances P.S. The module Generics export no data types, only the functions: canDoGenerics mkGenericRhs mkTyConGenericBinds validGenericInstanceType validGenericMethodType

  Read the article

• PostgreSQL function question

  - by maxxtack

  CREATE FUNCTION foo() RETURNS text LANGUAGE plperl AS $$ return 'foo'; $$; CREATE FUNCTION foobar() RETURNS text LANGUAGE plperl AS $$ return foo() . 'bar'; $$; I'm trying to compose results using multiple functions, but when i call foobar() i get an empty result.

  Read the article

• Why can't I *override* and *new* a Property (C#) at the same time?

  - by Tim Lovell-Smith

  According to this question it seems like you can do this for Methods. What I want to know is why it doesn't work when I try it with properties. public class Foo { public virtual object Value { get; set; } } public class Foo<T> : Foo { public override object Value { get { return base.Value; } set { base.Value = (T)value; //inject type-checking on sets } } public new T Value { get { return (T)base.Value; } set { base.Value = value; } } } Error message from C# 4.0 RC1 Error 1 The type 'ClassLibrary1.Foo' already contains a definition for 'Value' ClassLibrary1\Class1.cs 31 22 ClassLibrary1

  Read the article

• JQuery checkbox state is updated differently between group click() and $.each(obj.click())

  - by teerapap

  The code below doesn't work in the same behavior. The sequence of click event and calling foo() is different. I want to know why they behave different sequence between call click() and iterate the objects before call click() on each. <script type="text/javascript"> function foo(obj){ alert(obj.id+" ->"+obj.checked); } function clickAll(val){ if (val) { $(":checkbox").click(); } else { $(":checkbox").each(function(i,obj){ obj.click(); }); } } </script> </head> <body> <input type="checkbox" id="check1" onclick="foo(this)" /> a <input type="checkbox" id="check2" onclick="foo(this)" /> b <input type="checkbox" id="check3" onclick="foo(this)" /> c <input type="button" onclick="clickAll(true)" value="click all" /> <input type="button" onclick="clickAll(false)" value="click all each" /> </body>

  Read the article

• How do common web frameworks (Django, Rails, Symfony, etc) handle multiple instances of the same plu

  - by Steven Wei

  Do any of the popular web frameworks solve this problem well? Here's an example: suppose you're running one of these web frameworks and you want to install a blog plugin. Except instead of a single blog, you need to run two separate instances of the blog plugin, and you want to keep them segregated. Or say you want to install multiple instances of a user authentication plugin, because you want to segregate your administrative users from your customer user accounts. Or say you want to install multiple instances of a wiki plugin for different parts of your site, or multiple instances of a comments plugin, or whatever else. It seems to me that at the basic level, each instance of plugin would need to be able to configured with a different set of database tables, and would need to be 'installed' at a different URL path. My experience is mostly with Django and Symfony, and I haven't seen a clean solution to this problem in either of them. They both tend to assume that each plugin (or app, in Django's case) is only ever going to be installed once. I'm curious if the Rails folks have figured out a clean solution to this problem, or any other framework authors (in any language). And if you were going to design a solution to this problem, what would it look like?

  Read the article

• How do I copy an object in Java?

  - by Veera

  Consider the below code: DummyBean dum = new DummyBean(); dum.setDummy("foo"); System.out.println(dum.getDummy()); // prints 'foo' DummyBean dumtwo = dum; System.out.println(dumtwo.getDummy()); // prints 'foo' dum.setDummy("bar"); System.out.println(dumtwo.getDummy()); // prints 'bar' but it should print 'foo' So, I want to copy the 'dum' to dumtwo' and I want to change 'dum' without affecting the 'dumtwo'. But the above code is not doing that. When I change something in 'dum', the same change is happening in 'dumtwo' also. I guess, when I say dumtwo = dum, Java copies the reference only. So, is there any way to create a fresh copy of 'dum' and assign it to 'dumtwo' ?

  Read the article

• C++ Constructor Initializer List - using member functions of initialized members

  - by Andy

  I've run into the following a few times with initializer lists and I've never been able to explain it well. Can anyone explain why exactly the following fails (I don't have a compiler to catch typos, so bear with me): class Foo { public: Foo( int i ) : m_i( i ) {} //works with no problem int getInt() {return m_i;} ~Foo {} private: int m_i; }; class Bar { public: Bar() : m_foo( 5 ), //this is ok m_myInt( m_foo.getInt() ) //runtime error, seg 11 {} ~Bar() {} private: Foo m_foo; int m_myInt; }; When trying to call member functions of members initialized higher up the initializer list, I get seg faults. I seem to recall this is a known problem (or perhaps somehow by design) but I've never seen it well described. The attached example is contrived with plain old data types, but substitute the Bar::m_myInt with another object lacking a default (empty) constructor and the issue is more real. Can anyone enlighten me? Thanks!

  Read the article

• R: how can I concatenate a list?

  - by John

  I'm trying to produce a single variable which is a concatenation of two chars e.g to go from "p30s4" "p28s4" to "p30s4 p28s4". I've tried cat and paste as shown below. Both return empty variables. What am I doing wrong? > blah = c("p30s4","p28s4") > blah [1] "p30s4" "p28s4" > foo = cat(blah) p30s4 p28s4 > foo NULL > foo = paste(cat(blah)) p30s4 p28s4 > foo character(0)

  Read the article

• Java: autofiltering list?

  - by Jason S

  I have a series of items arriving which are used in one of my data structures, and I need a way to keep track of those items that are retained. interface Item {} class Foo implements Item { ... } class Baz implements Item { ... } class StateManager { List<Foo> fooList; Map<Integer, Baz> bazMap; public List<Item> getItems(); } What I want is that if I do the following: for (int i = 0; i < SOME_LARGE_NUMBER; ++i) { /* randomly do one of the following: * 1) put a new Foo somewhere in the fooList * 2) delete one or more members from the fooList * 3) put a new Baz somewhere in the bazMap * 4) delete one or more members from the bazMap */ } then if I make a call to StateManager.getItems(), I want to return a list of those Foo and Baz items, which are found in the fooList and the bazMap, in the order they were added. Items that were deleted or displaced from fooList and bazMap should not be in the returned list. How could I implement this? SOME_LARGE_NUMBER is large enough that I don't have the memory available to retain all the Foo and Baz items, and then filter them.

  Read the article

• Manipulating source packages from Hackage how to easy deploy to several windowsboxes?

  - by Jonke

  Recently when I have found good sources packages for ghc 6.12/6.10 on Hackage I've been forced to do some minor or major changes to the cabal files to make those packages to work under windows. Besides to fork and merge my fixes with github, what seems to be the best way/ good enough practice to take these modified builds to a couple of other windows boxes that only has a basic haskell platform installed? I should prefer if I somehow could work with the cabal-install because that is what one normally use. Should one put the modfied build dirs on a shared/networked dir and mount from the targeted windows box? Say something like this: on machine prepare cabal fetch foo cabal unpack foo cd foo edit .cabal and .hs cabal configure cabal build On machine useanddevelopnormal cd machinepreparemount cd foo cabal install

  Read the article

• Python recursion with list returns None

  - by newman

  def foo(a): a.append(1) if len(a) > 10: print a return a else: foo(a) Why this recursive function returns None (see transcript below)? I can't quite understand what I am doing wrong. In [263]: x = [] In [264]: y = foo(x) [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] In [265]: print y None

  Read the article

• awk/sed/bash to merge/concatenate data

  - by Kyle

  Trying to merge some data that I have. The input would look like so: foo bar foo baz boo abc def abc ghi And I would like the output to look like: foo bar baz boo abc def ghi I have some ideas using some arrays in a shell script, but I was looking for a more elegant or quicker solution.

  Read the article

• In what circumstances are instance variables declared as '_var' in 'use fields' private?

  - by Pedro Silva

  I'm trying to understand the behavior of the fields pragma, which I find poorly documented, regarding fields prefixed with underscores. This is what the documentation has to say about it: Field names that start with an underscore character are made private to the class and are not visible to subclasses. Inherited fields can be overridden but will generate a warning if used together with the -w switch. This is not consistent with its actual behavior, according to my test, below. Not only are _-prefixed fields visible within a subclass, they are visible within foreign classes as well (unless I don't get what 'visible' means). Also, directly accessing the restricted hash works fine. Where can I find more about the behavior of the fields pragma, short of going at the source code? { package Foo; use strict; use warnings; use fields qw/a _b __c/; sub new { my ( $class ) = @_; my Foo $self = fields::new($class); $self->a = 1; $self->b = 2; $self->c = 3; return $self; } sub a : lvalue { shift->{a} } sub b : lvalue { shift->{_b} } sub c : lvalue { shift->{__c} } } { package Bar; use base 'Foo'; use strict; use warnings; use Data::Dumper; my $o = Bar->new; print Dumper $o; ##$VAR1 = bless({'_b' => 2, '__c' => 3, 'a' => 1}, 'Foo'); $o->a = 4; $o->b = 5; $o->c = 6; print Dumper $o; ##$VAR1 = bless({'_b' => 5, '__c' => 6, 'a' => 4}, 'Foo'); $o->{a} = 7; $o->{_b} = 8; $o->{__c} = 9; print Dumper $o; ##$VAR1 = bless({'_b' => 8, '__c' => 9, 'a' => 7}, 'Foo'); }

  Read the article

• MVC design in Cocoa - are all 3 always necessary? Also: naming conventions, where to put Controller

  - by Nektarios

  I'm new to MVC although I've read a lot of papers and information on the web. I know it's somewhat ambiguous and there are many different interpretations of MVC patterns.. but the differences seem somewhat minimal My main question is - are M, V, and C always going to be necessary to be doing this right? I haven't seen anyone address this in anything I've read. Examples (I'm working in Cocoa/Obj-c although that shouldn't much matter).. 1) If I have a simple image on my GUI, or a text entry field that is just for a user's convenience and isn't saved or modified, these both would be V (view) but there's no M (no data and no domain processing going on), and no C to bridge them. So I just have some aspects that are "V" - seems fine 2) I have 2 different and visible windows that each have a button on them labeled as "ACTIVATE FOO" - when a user clicks the button on either, both buttons press in and change to say "DEACTIVATE FOO" and a third window appears with label "FOO". Clicking the button again will change the button on both windows to "ACTIVATE FOO" and will remove the third "FOO" window. In this case, my V consists of the buttons on both windows, and I guess also the third window (maybe all 3 windows). I definitely have a C, my Controller object will know about these buttons and windows and will get their clicks and hold generic states regarding windows and buttons. However, whether I have 1 button or 10 button, my window is called "FOO" or my window is called "BAR", this doesn't matter. There's no domain knowledge or data here - just control of views. So in this example, I really have "V" and "C" but no "M" - is that ok? 3) Final example, which I am running in to the most. I have a text entry field as my View. When I enter text in this, say a number representing gravity, I keep it in a Model that may do things like compute physics of a ball while taking in to account my gravity parameter. Here I have a V and an M, but I don't understand why I would need to add a C - a controller would just accept the signals from the View and pass it along to the Model, and vice versa. Being as the C is just a pure passthrough, it's really "junk" code and isn't making things any more reusable in my opinion. In most situations, when something changes I will need to change the C and M both in nearly identical ways. I realize it's probably an MVC beginner's mistake to think most situations call for only V and M.. leads me in to next subject 4) In Cocoa / Xcode / IB, I guess my Controllers should always be an instantiated object in IB? That is, I lay all of my "V" components in IB, and for each collection of View objects (things that are related) I should have an instantiated Controller? And then perhaps my Models should NOT be found in IB, and instead only found as classes in Xcode that tie in with Controller code found there. Is this accurate? This could explain why you'd have a Controller that is not really adding value - because you are keeping consistent.. 5) What about naming these things - for my above example about FOO / BAR maybe something that ends in Controller would be the C, like FancyWindowOpeningController, etc? And for models - should I suffix them with like GravityBallPhysicsModel etc, or should I just name those whatever I like? I haven't seen enough code to know what's out there in the wild and I want to get on the right track early on Thank you in advance for setting me straight or letting me know I'm on the right track. I feel like I'm starting to get it and most of what I say here makes sense, but validation of my guessing would help me feel confident..

  Read the article

< Previous Page | 50 51 52 53 54 55 56 57 58 59 60 61  | Next Page >