Tutorial by Examples: n

CLP(FD) constraints are completely pure relations. They can be used in all directions for declarative integer arithmetic: ?- X #= 1+2. X = 3. ?- 3 #= Y+2. Y = 1.

In oracle, the difference (in days and/or fractions thereof) between two DATEs can be found using subtraction: SELECT DATE '2016-03-23' - DATE '2015-12-25' AS difference FROM DUAL; Outputs the number of days between the two dates: DIFFERENCE ---------- 89 And: SELECT TO_DATE( '201...

Our example array: arr=(a b c d e f) Using a for..in loop: for i in "${arr[@]}"; do echo "$i" done 2.04 Using C-style for loop: for ((i=0;i<${#arr[@]};i++)); do echo "${arr[$i]}" done Using while loop: i=0 while [ $i -lt ${#arr[@]} ]; do...

The MEDIAN function since Oracle 10g is an easy to use aggregation function: SELECT MEDIAN(SAL) FROM EMP It returns the median of the values Works on DATETIME values too. The result of MEDIAN is computed by first ordering the rows. Using N as the number of rows in the group, Oracle calcula...

Following code will release the lock. There will be no problem. Behind the scenes lock statement works as try finally lock(locker) { throw new Exception(); } More can be seen in the C# 5.0 Specification: A lock statement of the form lock (x) ... where x is an expression of a referenc...

Partial application means calling a function with less arguments than it has and saving the result as another function (that waits for the rest of the arguments). multiplyBy: Int -> Int -> Int multiplyBy x y = x * y multiplyByTwo : Int -> Int -- one Int has disappeared! we ...

The function toupper will convert a string to upper case (capital letters). For example: BEGIN { greeting = "hello" loud_greeting = toupper(greeting) print loud_greeting } This code will output "HELLO" when run.

We create a new concurrent process by calling the spawn function. The spawn function will get as parameter a function Fun that the process will evaluate. The return value of the spawn function is the created process identifier (pid). 1> Fun = fun() -> 2+2 end. #Fun<erl_eval.20.52032458&gt...

Enum classes as any other classes can have a constructor and be initialized enum class Color(val rgb: Int) { RED(0xFF0000), GREEN(0x00FF00), BLUE(0x0000FF) }

Enum classes can also declare members (i.e. properties and functions). A semicolon (;) must be placed between the last enum object and the first member declaration. If a member is abstract, the enum objects must implement it. enum class Color { RED { override val rgb: Int = 0xFF0000 ...

enum class Color { RED, GREEN, BLUE } Each enum constant is an object. Enum constants are separated with commas.

The routing configuration is included in your app/config/config.yml file, by default the app/config/routing.yml file. From there you can link to your own routing configuration in a bundle # app/config/routing.yml app: resource: "@AppBundle/Resources/config/routing.yml" It migh...

The routing configuration is included in your app/config/config.yml file, by default the app/config/routing.yml file. From there you can link to the controllers that have annotated routing configuration: # app/config/routing.yml app: resource: "@AppBundle/Controller" type: ...

A browser's debugging console can be used in order to print simple messages. This debugging or web console can be directly opened in the browser (F12 key in most browsers – see Remarks below for further information) and the log method of the console Javascript object can be invoked by typing the fol...

Sometimes, we may open a file which we do not have permission to write in Vim without using sudo. Use this command to save a read-only file edited in Vim. :w !sudo tee > /dev/null % Which you could map to :w!! in your .vimrc: cmap w!! w !sudo tee > /dev/null % You will be presented a ...

The size of a canvas is the area it occupies on the page and is defined by the CSS width and height properties. canvas { width : 1000px; height : 1000px; } The canvas resolution defines the number of pixels it contains. The resolution is set by setting the canvas element width and heigh...

Starter code to create and remove a full page canvas that responds to resize events via javascript. var canvas; // Global canvas reference var ctx; // Global 2D context reference // Creates a canvas function createCanvas () { const canvas = document.createElement(&q...

Many times when working with the canvas you will need to have a canvas to hold some intrum pixel data. It is easy to create an offscreen canvas, obtain a 2D context. An offscreen canvas will also use the available graphics hardware to render. The following code simply creates a canvas and fills it ...

This example will show you how to create a simple animation using the canvas and the 2D context. It is assumed you know how to create and add a canvas to the DOM and obtain the context // this example assumes ctx and canvas have been created const textToDisplay = "This is an example that uses...

There are many situation where you want to draw an image that is rotated, scaled, and translated. The rotation should occur around the center of the image. This is the quickest way to do so on the 2D canvas. These functions a well suited to 2D games where the expectation is to render a few hundred e...