state

I've read many research papers on this topic, and they usually argue that arrays are implemented using Monads. But none of these papers gave a clear definition of how the "type" Array itself should be defined, they only gave definitions for the functions using monads to access or modify this type. How are arrays, having O(1) time to access or modify an indexed element, implemented in Haskell ?! (such as STUArray and MArray) How are arrays, having O(1) time to access or modify an indexed element, implemented in Haskell They are implemented via primitive operations in the runtime system for

In my react component im trying to implement a simple spinner while an ajax request is in progress - im using state to store the loading status. For some reason this piece of code below in my React component throws this error Can only update a mounted or mounting component. This usually means you called setState() on an unmounted component. This is a no-op. Please check the code for the undefined component. If I get rid of the first setState call the error goes away. constructor(props) { super(props); this.loadSearches = this.loadSearches.bind(this); this.state = { loading: false } }

I'm still fairly new at React, but I've been grinding along slowly and I've encountered something I'm stuck on. I am trying to build a "timer" component in React, and to be honest I don't know if I'm doing this right (or efficiently). In my code below, I set the state to return an object { currentCount: 10 } and have been toying with componentDidMount , componentWillUnmount , and render and I can only get the state to "count down" from 10 to 9. Two-part question: What am I getting wrong? And, is there a more efficient way of going about using setTimeout (rather than using componentDidMount &

As a fairly experienced ASP.Net developer just recently starting using MVC, I find myself struggling a bit to change my mindset from a traditional "server control and event handler" way of doing things, into the more dynamic MVC way of things. I think I am slowly getting there, but sometimes the MVC "magic" throws me off. My current scenario is to create a web page that allows the user to browse a local file, upload it to the server and repeat this until he has a list of files to work with. When he is happy with the file list (which will be displayed in a grid on the page), he will click a

Regarding the Apple documentation there is no way to handle the phone state while the app is suspended: https://developer.apple.com/documentation/coretelephony/ctcallcenter "While it is suspended, your application does not receive call events" Is this also true for the "background" state? (As the background state is not the same with the "suspended" app state regarding the states described in the Apple documentation) https://web.archive.org/web/20140824215114/https://developer.apple.com/library/ios/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/ManagingYourApplicationsFlow

yesterday I noticed the possibility to integrate Fragments in older API Levels through the Compatibility package, but thats not really essential for the question. :) I have a Button with an OnClickListener Button button = (Button) findViewById(R.id.button); button.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { doSomething(); button.setPressed(true); } }); Because of the actual clicking, it is shown as pressed and after releasing the click, the button state is not pressed and stays that way. Is there a simple way that keeps the button state pressed after