Tutorial by Examples: l

Note that this deals with the creation of a collection of type Map, which is distinct from the map method. Map Creation Map[String, Int]() val m1: Map[String, Int] = Map() val m2: String Map Int = Map() A map can be considered a collection of tuples for most operations, where the first e...

A counter using an FPGA style flip-flop initialisation: module counter( input clk, output reg[7:0] count ) initial count = 0; always @ (posedge clk) begin count <= count + 1'b1; end A counter implemented using asynchronous resets suitable for ASIC synthesis: module counter...

A non-blocking assignment (<=) is used for assignment inside edge-sensitive always blocks. Within a block, the new values are not visible until the entire block has been processed. For example: module flip( input clk, input reset ) reg f1; reg f2; always @ (posedge clk) begin ...

A 2-tuple or a 3-tuple represent a group of related items. (Points in 2D space, RGB values of a color, etc.) A 1-tuple is not very useful since it could easily be replaced with a single int. A 0-tuple seems even more useless since it contains absolutely nothing. Yet it has properties that make it v...

Demo HTML <script type="x-template" id="form-template"> <label>{{inputLabel}} :</label> <input type="text" v-model="name" /> </script> <div id="app"> <h2>{{appName}}</h2> <form-co...

//Swift imageView.tintColor = UIColor.redColor() imageView.image = imageView.image?.imageWithRenderingMode(.AlwaysTemplate) //Swift 3 imageView.tintColor = UIColor.red imageView.image = imageView.image?.withRenderingMode(.alwaysTemplate) //Objective-C imageView.tintColor = [UIColor redCol...

The Scala compiler prefixes every argument in the parameter list by default with val. This means that, by default, case classes are immutable. Each parameter is given an accessor method, but there are no mutator methods. For example: case class Foo(i: Int) val fooInstance = Foo(1) val j = fooIn...

A true relational database must go beyond throwing data into a few tables and writing some SQL statements to pull that data out. At best a badly designed table structure will slow the execution of queries and could make it impossible for the database to function as intended. A database table shoul...

Apply will be used when when table valued function in the right expression. create a Department table to hold information about departments. Then create an Employee table which hold information about the employees. Please note, each employee belongs to a department, hence the Employee table has ref...

Below is a simple example which shows average item's price of each item per weekday. First, suppose we have a table which keeps daily records of all items' prices. CREATE TABLE tbl_stock(item NVARCHAR(10), weekday NVARCHAR(10), price INT); INSERT INTO tbl_stock VALUES ('Item1', 'Mon', 110), (...

In normal mode, we can increment the nearest number on the line at or after the cursor with <C-a> and decrement it with <C-x>. In the following examples, the cursor position is indicated by ^. Incrementing and decrementing numbers for i in range(11): ^ <C-x> decrements ...

The core idea behind the Feature Branch Workflow is that all feature development should take place in a dedicated branch instead of the master branch. This encapsulation makes it easy for multiple developers to work on a particular feature without disturbing the main codebase. It also means the mast...

Future<Results> costlyQuery() { var completer = new Completer(); database.query("SELECT * FROM giant_table", (results) { // when complete completer.complete(results); }, (error) { completer.completeException(error); }); // this returns essentially im...

Common Lisp REPL is an interactive environment. Every form written after the prompt is evaluated, and its value is afterwards printed as result of the evaluation. So the simplest possible “Hello, World!” program in Common Lisp is: CL-USER> "Hello, World!" "Hello, World!" CL...

Creating and configuring Sprite and TextField objects at runtime can be costly if you are creating hundreds of thousands of these on a single frame. Therefore a common trick is "pooling" these objects for later reuse. Remember we are not just trying to optimize the creation time (new Sprit...

Flash dispatches Events for most of its objects. One of the most basic event is ENTER_FRAME, which is dispatched (at the framerate of the SWF) on every display list object. import flash.display.Sprite; import flash.events.Event; var s:Sprite = new Sprite(); s.addEventListener(Event.ENTER_FRAME...

class Person(models.Model): name = models.CharField(max_length=50) description = models.TextField() class Club(models.Model): name = models.CharField(max_length=50) members = models.ManyToManyField(Person) Here we define a relationship where a club has many Persons and memb...

UITextView has built in support to auto detect a variety of data. The data that is able to be auto-detected currently includes: enum { UIDataDetectorTypePhoneNumber = 1 << 0, UIDataDetectorTypeLink = 1 << 1, UIDataDetectorTypeAddress = 1 << 2, UID...

Single JAR Sometimes you have a local JAR file you need to add as a dependency to your Gradle build. Here's how you can do this: dependencies { compile files('path/local_dependency.jar') } Where path is a directory path on your filesystem and local_dependency.jar is the name of your local...

It is possible to find the first element of a Stream that matches a condition. For this example, we will find the first Integer whose square is over 50000. IntStream.iterate(1, i -> i + 1) // Generate an infinite stream 1,2,3,4... .filter(i -> (i*i) > 50000) // Filter to find element...