Tutorial by Examples: l

An Akka MessageDispatcher is what makes Akka Actors "tick", it is the engine of the machine so to speak. All MessageDispatcher implementations are also an ExecutionContext, which means that they can be used to execute arbitrary code, for instance Futures. Every ActorSystem will have a def...

Listing docker-machines will return the state, address and version of Docker of each docker machines. docker-machine ls Will print something like: NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS docker-machine-1 - ovh Running ...

In Common Lisp, if is the simplest conditional construct. It has the form (if test then [else]) and is evaluated to then if test is true and else otherwise. The else part can be omitted. (if (> 3 2) "Three is bigger!" "Two is bigger!") ;;=> "Three is bigger...

docker save -o ubuntu.latest.tar ubuntu:latest This command will save the ubuntu:latest image as a tarball archive in the current directory with the name ubuntu.latest.tar. This tarball archive can then be moved to another host, for example using rsync, or archived in storage. Once the tarball h...

Use the lazy_static crate to create global immutable variables which are initialized at runtime. We use HashMap as a demonstration. In Cargo.toml: [dependencies] lazy_static = "0.1.*" In main.rs: #[macro_use] extern crate lazy_static; lazy_static! { static ref HASHMAP: Hash...

Install Docker Engine. If you get a Permission denied error, Run sudo -i before the two commands below, then exit. Pull Docker Compose to /usr/local/bin/docker-compose. curl -L https://github.com/docker/compose/releases/download/1.7.1/docker-compose-`uname -s`-`uname -m` > /usr/loc...

Orders Table CustomerIdProductIdQuantityPrice12510013220014150021450356700 When grouping by a specific column, only unique values of this column are returned. SELECT customerId FROM orders GROUP BY customerId; Return value: customerId123 Aggregate functions like count() apply to each group...

Unlike the loops in nearly every other programming language in use today, the LOOP in Common Lisp can be used as an expression: (let ((doubled (loop for x from 1 to 10 collect (* 2 x)))) doubled) ;; ==> (2 4 6 8 10 12 14 16 18 20) (loop for x from 1 to 10 sum x) ...

LOOP has its own IF statement that can control how the clauses are executed: (loop repeat 1000 for x = (random 100) if (evenp x) collect x into evens else collect x into odds finally (return (values evens odds))) Combining multiple clauses in an IF ...

Another way you can generate a range of dates is by utilizing a Tally Table to create the dates between the range: Declare @FromDate Date = '2014-04-21', @ToDate Date = '2014-05-02' ;With E1(N) As (Select 1 From (Values (1), (1), (1), (1), (1), (1), (1), (1), (1), (1)) DT...

We can get a comma delimited string from multiple rows using coalesce as shown below. Since table variable is used, we need to execute whole query once. So to make easy to understand, I have added BEGIN and END block. BEGIN --Table variable declaration to store sample records DECLARE @...

COALESCE() returns the first NON NULL value in a list of arguments. Suppose we had a table containing phone numbers, and cell phone numbers and wanted to return only one for each user. In order to only obtain one, we can get the first NON NULL value. DECLARE @Table TABLE (UserID int, PhoneNumber va...

Here we demonstrate how to process lists recursively using OCaml's pattern matching syntax. let rec map f lst = match lst with | [] -> [] | hd::tl -> (f hd)::(map f tl) In this case, the pattern [] matches the empty list, while hd::tl matches any list that has at least one element...

If you want to make sure cookies are enabled before using them, you can use navigator.cookieEnabled: if (navigator.cookieEnabled === false) { alert("Error: cookies not enabled!"); } Note that on older browsers navigator.cookieEnabled may not exist and be undefined. In those case...

Function Factorial(Value As Long) As Long If Value = 0 Or Value = 1 Then Factorial = 1 Else Factorial = Factorial(Value - 1) * Value End If End Function

Early Bound (with a reference to Microsoft Scripting Runtime) Sub EnumerateFilesAndFolders( _ FolderPath As String, _ Optional MaxDepth As Long = -1, _ Optional CurrentDepth As Long = 0, _ Optional Indentation As Long = 2) Dim FSO As Scriptin...

TYPO3 has extensive documentation. This documentation is linked here, so people can find stuff that is not documented here. Main Documentation The documentation of TYPO3 CMS is collected at docs.typo3.org, there is a list of all documentation for the core, and documentation for extensions. Promin...

TYPO3 can be solely installed with the PHP dependency manager composer. Composer has to be available on the server, then a TYPO3 project can be started by using the base distribution. composer create-project typo3/cms-base-distribution . This will pull the TYPO3 core from the git repository, dow...

Employees table : | ID | FirstName | LastName | Gender | Salary | +------+-----------+----------+--------+--------+ | 1 | Jahangir | Alam | Male | 70000 | | 2 | Arifur | Rahman | Male | 60000 | | 3 | Oli | Ahammed | Male | 45000 | | 4 | Sima | Sulta...

Employees table : | ID | FirstName | LastName | Gender | Salary | +------+-----------+----------+--------+--------+ | 1 | Mark | Hastings | Male | 60000 | | 1 | Mark | Hastings | Male | 60000 | | 2 | Mary | Lambeth | Female | 30000 | | 2 | Mary | Lambe...