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val list = listOf(1,2,3,4,5,6) //filter out even numbers val even = list.filter { it % 2 == 0 } println(even) //returns [2,4]

The two main libraries providing pattern matching in Common Lisp are Optima and Trivia. Both provide a similar matching API and syntax. However trivia provides a unified interface to extend matching, defpattern.

Rails is shipped by default with ActiveRecord, an ORM (Object Relational Mapping) derived from the pattern with the same name. As an ORM, it is built to handle relational-mapping, and more precisely by handling SQL requests for you, hence the limitation to SQL databases only. However, you can stil...

This is a sample adapter code. public class SampleAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> { private static final int FOOTER_VIEW = 1; // Define a view holder for Footer view public class FooterViewHolder extends ViewHolder { public FooterViewHolder(View ite...

Strategy: Strategy is a behavioural pattern, which allows to change the algorithm dynamically from a family of related algorithms. UML of Strategy pattern from Wikipedia : import java.util.*; /* Interface for Strategy */ interface OfferStrategy { public String getName(); public dou...

from scipy.sparse import csr_matrix A = csr_matrix([[1,0,2],[0,3,0]]) >>>A <2x3 sparse matrix of type '<type 'numpy.int64'>' with 3 stored elements in Compressed Sparse Row format> >>> A.todense() matrix([[1, 0, 2], [0, 3, 0]]) >>&g...

An Explain infront of a select query shows you how the query will be executed. This way you to see if the query uses an index or if you could optimize your query by adding an index. Example query: explain select * from user join data on user.test = data.fk_user; Example result: id select_type...

Fire after the initialization of the content of the component or directive has finished. (Right after OnInit) import { Component, AfterContentInit } from '@angular/core'; @Component({ selector: 'so-aftercontentinit-component', templateUrl: 'aftercontentinit-component.html', styl...

Fire after the view has been fully initialized. (Only available for components) import { Component, AfterContentChecked } from '@angular/core'; @Component({ selector: 'so-aftercontentchecked-component', templateUrl: 'aftercontentchecked-component.html', styleUrls: ['aftercontentc...

Fires after initializing both the component view and any of its child views. This is a useful lifecycle hook for plugins outside of the Angular 2 ecosystem. For example, you could use this method to initialize a jQuery date picker based on the markup that Angular 2 has rendered. import { Component,...

Fire after the check of the view, of the component, has finished. (Only available for components) import { Component, AfterViewChecked } from '@angular/core'; @Component({ selector: 'so-afterviewchecked-component', templateUrl: 'afterviewchecked-component.html', styleUrls: ['afte...

CREATE TRIGGER BooksDeleteTrigger ON MyBooksDB.Books AFTER DELETE AS INSERT INTO BooksRecycleBin SELECT * FROM deleted; GO

Check the app's authorization status with: //Swift let status: CLAuthorizationStatus = CLLocationManager.authorizationStatus() //Objective-C CLAuthorizationStatus status = [CLLocationManager authorizationStatus]; Test the status against the follow constants: //Swift switch status { case ...

(in-package #:asdf-user) (defsystem #:foo :components ((:file "foo")) :in-order-to ((asdf:test-op (asdf:load-op :foo))) :perform (asdf:test-op (o c) (uiop:symbol-call :foo-tests 'run-tests))) (defsystem #:foo-tests :name "foo-test" :compo...

The fmt.Stringer interface requires a single method, String() string to be satisfied. The string method defines the "native" string format for that value, and is the default representation if the value is provided to any of the fmt packages formatting or printing routines. package main ...

1. Character Class Character class is denoted by []. Content inside a character class is treated as single character separately. e.g. suppose we use [12345] In the example above, it means match 1 or 2 or 3 or 4 or 5 . In simple words, it can be understood as or condition for single characters (...

Observe the notifications UIKeyboardWillShowNotification and UIKeyboardWillHideNotification, update the scrollView content insets according to keyboard height, then scroll to the focused control. - (void)viewDidLoad { [super viewDidLoad]; // register for keyboard notifications [[...

Session cookies parameters are important both if you have a need to maintain session while getting from one subdomain to another or when, in contrary, you host backend app under /admin URL and want handle session separately. $config = [ // ... 'components' => [ // ... ...

A less known builtin feature is Controller Action injection using the FromServicesAttribute. [HttpGet] public async Task<IActionResult> GetAllAsync([FromServices]IProductService products) { return Ok(await products.GetAllAsync()); } An important note is that the [FromServices] c...

Given a Person struct struct Person { let name: String let birthYear: Int? } and an Array of Person(s) let persons = [ Person(name: "Walter White", birthYear: 1959), Person(name: "Jesse Pinkman", birthYear: 1984), Person(name: "Skyler White&quo...