state

lazy list computed using mutable state?

由 断了今生、忘了曾经 提交于 2019-12-10 05:24:34
问题 I'd like to figure out in general how to use mutable state in the computation of lazy lists. For instance, here is a naive Sieve of Eratosthenes implemented using a mutable array (source): import Control.Monad.ST import Data.Array.ST import Data.Array.Unboxed import Control.Monad import Data.List prime :: Int -> UArray Int Bool prime n = runSTUArray $ do arr <- newArray ( 2 , n ) True :: ST s ( STUArray s Int Bool ) forM_ ( takeWhile ( \x -> x*x <= n ) [ 2 .. n ] ) $ \i -> do ai <- readArray

Why is this factory returning a $$state object instead of response.data?

由 ∥☆過路亽．° 提交于 2019-12-10 03:21:14
问题 So I have a collection of objects in the server I want to populate an ng-repeat when the page loads. I had a made a factory which fetched the list from a resource on the server, like so: app.factory('objectArray', ['$http', function($http) { // This is returning a $$state object // instead of response.data... return $http.post('/get_collection').then(function(response) { console.log(response.data); return response.data; }); }]); I've had this code work before when using ui-router and the

Haskell : reference to previously updated elements of list within the update function

由 巧了我就是萌 提交于 2019-12-10 02:28:55
问题 Say I have the following definitions data Book = Book {id :: Int, title :: String} type Shelf = [Book] Assuming I have a hypothetical function (upd is for update) updShelf :: Shelf -> Shelf updShelf all@(book : books) = updBook book : updShelf books All fine so far. Now let's say the updateBook function needs to refer to the updated book three books before it i.e updateBook for book at position 5 in bookshelf need to refer to book at position 2 (assume first three books need no such reference

Why use InheritedWidget while we can use Broadcast Streams | StreamBuilder and Static Variables [closed]

由 大憨熊 提交于 2019-12-09 23:58:05
问题 Closed . This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed last year . Why use InheritedWidget while we can use Broadcast Streams | StreamBuilder and Static Variables? Why should we bother about redux, scoped model, etc. while we can have a simple and clean architecture? 回答1: Streams/Sink definitely are excellent to store a state. There are some

Save latest text from Edittext and restore it after onDestroy

由 橙三吉。 提交于 2019-12-09 22:22:00
问题 For my quote creator app, if the user wrote a text in the app and by accident closed the app and started it again, all the text will be gone. I want ofcourse to prevent that, and I have tried a common solution without succses: This is what I have done so far. I have removed unrelated code. public static EditText mEditText; private String savedText; private static final String SAVED_TEXT_KEY = ""; @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState);

prevState in componentDidUpdate is the currentState?

由 我只是一个虾纸丫 提交于 2019-12-09 16:57:32
问题 I've used componentDidUpdate() in the past and it has worked as expected. This time, however, I did componentDidUpdate(prevProps, prevState) { if (prevState.object.someString !== this.state.object.someString) { console.log(true); } } and true is never logged. I logged both state objects to the console and found out they are exactly the same one: the current state. Is this a bug? What am I missing here? Thank you. Edit: I tried to do the same thing with componentWillUpdate(nextProps, nextState

Android: saving application state when going to the “background”

由 大城市里の小女人 提交于 2019-12-09 13:05:09
问题 I have a complex Android app with a decent amount of application state that needs to be persisted (in a specific format). Writing out the data is not an instantaneous operation and so it would be ideal to minimize persisting it unnecessarily. Because of the persistence overhead it is not practical to persist the state every time it is changed. Ideally, persisting state would be triggered when the app is "backgrounded" by the user tapping the 'home' button or tapping the 'back' button on the

Access $state inside template

由 不打扰是莪最后的温柔 提交于 2019-12-09 11:03:23
问题 Background I create an app with a menu on the left which contains several menu items. When the user clicks on an item (or access it via an URL), I want to highlight the item (i.e. apply the class 'active' on the corresponding <li> ). Note : I handle routes with ui.router . What I tried Up to now, I try to use a ng-class directive : <div class="col-sm-3 col-md-2 sidebar"> <ul class="nav nav-sidebar"> <li ng-class="{active: current=='container.item1'}"> <a href="#/a/item1">Item 1</a> </li> <li

How to Handle UI State in Redux/React - Redux-UI?

由 微笑、不失礼 提交于 2019-12-09 02:16:26
I am researching into what is the best way to store the UI state, Should I use something like Redux-UI ( https://github.com/tonyhb/redux-ui ) to store/manage the UI state? or should I create my own actions/reducers for the UI? Also... when I have stored the UI state, how do I make sure if the browser is refreshed, I still have exactly the same state of the page? Just as a normal web page would including Data taken from the server. I have Redux with thunk middle wear implemented and a store. I have worked with React for the past couple of months thus far. Thanks! Quinton Our team has spent some

onCreateDrawableState never call

由 混江龙づ霸主 提交于 2019-12-08 22:10:04
问题 I have tye to add new state to RelativeLayout but onCreateDrawableState method is never call. My class is: public class UnreadableRelativeLayout extends RelativeLayout { private static final int[] STATE_UNREADED = {R.attr.state_unreaded}; private boolean isUnreaded = false; public UnreadableRelativeLayout(Context context) { super(context); } public UnreadableRelativeLayout(Context context, AttributeSet attrs) { super(context, attrs); } public UnreadableRelativeLayout(Context context,
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