Tutorial by Examples: g

In this question, @Viclib asked about using rewrite rules to exploit typeclass laws to eliminate some overloaded function calls: Mind the following class: class ListIsomorphic l where toList :: l a -> [a] fromList :: [a] -> l a I also demand that toList . fromList == id. H...

The IEnumerable<T> interface is the base interface for all generic enumerators and is a quintessential part of understanding LINQ. At its core, it represents the sequence. This underlying interface is inherited by all of the generic collections, such as Collection<T>, Array, List<T&g...

The div is a block-level element, i.e it occupies the whole of the page width and the siblings are place one below the other irrespective of their width. <div> <p>This is DIV 1</p> </div> <div> <p>This is DIV 2</p> </div> The output of...

To create seeders, you may use the make:seeder Artisan command. All seeders generated will be placed in the database/seeds directory. $ php artisan make:seeder MoviesTableSeeder Generated seeders will contain one method: run. You may insert data into your database in this method. <?php us...

1. Switch to a frame by Index. Here we are switching to index 1. Index refers to the order of frames on the page. This should be used as a last resort, as frame id or names are much more reliable. driver.SwitchTo().Frame(1); 2. Switch to a frame by Name driver.SwitchTo().Frame("Name_Of_Fr...

Some devices connected through a serial port send data to your program at a constant rate (streaming data) or send data at unpredictable intervals. You can configure the serial port to execute a function automatically to handle data whenever it arrives. This is called the "callback function&quo...

Set a convenience method in your base model namespace Base; class Model extends \Phalcon\Mvc\Model { public function sanitize($attr, $filterName) { $filter = $this->getDI()->get('filter'); $this->$attr = $filter->sanitize($this->$attr, $filterName); ...

The Scala compiler can also deduce type parameters when polymorphic methods are called, or when generic classes are instantiated: case class InferedPair[A, B](a: A, b: B) val pairFirstInst = InferedPair("Husband", "Wife") //type is InferedPair[String, String] // Equiv...

To split strings, Guava introduces the Splitter class. Why not use Java's splitting capabilities? As a rule, Guava does not duplicate functionality that is readily available in Java. Why then do we need an additional Splitter class? Do the split methods in Java's String class not provide us with a...

#include <Servo.h> Servo srv; void setup() { srv.attach(9); // Attach to the servo on pin 9 } To use a servo, you need to call attach() function first. It starts generating a PWM signal controlling a servo on a specified pin. On boards other than Arduino Mega, use of Servo lib...

Returns the number of characters of the given String Considerations If a number is given instead a String, the result will be the length of the String representing the given number. I.e. If we execute length(12345) the result will be the same as length("12345"), that is 5 If...

To assign a value to a previously declared variable, use the assignment operator, =: a = 6; b = "Foo"; As an alternative to independent declaration and assignment, it is possible to perform both steps in one statement: var a = 6; let b = "Foo"; It is in this syntax that...

Here are some example on how to add new filters/functions to twig,the synax for adding Twig_Functions are the same as the Twig_Filter ones, just change the keywords accordingly <?php $twig = new Twig_Environment($loader); /* You can chain a global function */ $twig->addFilter(ne...

You can group all your custom functions/filters/tests/... inside a custom Twig_Extension class: ProjectTwigExtension class ProjectTwigExtension extends Twig_Extension { public function getFunctions() { return array( new Twig_SimpleFunction('twig_function_name', array($...

OneGet was originally a product from the Open Source Technology Center at Microsoft. Not only is it inspired by open-source Linux package managers, OneGet itself is also open source. It's now part of PowerShell As opposed to Unix based package managers (such as apt-get, yum, or dpkg), Windows allow...

This is an example on how to call a web service from salesforce. The code below is calling a REST based service hosted on data.gov to find farmers markets close to the zipcode. Please remember in order to invoke a HTTP callout from your org, you need to tweak the remote settings for the org. strin...

Creation To create a Custom Setting, go to: Classic Setup > Develop > Custom Settings > New Lightning Setup > Custom Code > Custom Settings > New Create your setting (see the Remarks later in this document for the differences between Hierarchy & List custom settings). You...

Custom Setting Custom Setting Field Custom Setting Field Value When the field is checked the validation rule will be disabled, for the running user or in this example, their profile - The rule can also be disabled for a whole Salesforce org - Validation Rule AND( /* the below is the...

Explanation In this example a simple Trigger has been created to change the Close Date of an Opportunity, that's about to be inserted or updated, to a date 10 days in the future. The Apex Controller custom setting's checkbox field enables the code to be disabled at the user / profile / org level. ...

Selecting all accounts that have open opportunity records under them SELECT Id, Name FROM Account WHERE AccountId IN (SELECT Id FROM Opportunity WHERE IsClosed = false)