Tutorial by Examples: on

Traditionally in Prolog, "functions" (with one output and bound inputs) were written as regular predicates: mangle(X,Y) :- Y is (X*5)+2. This can create the difficulty that if a function-style predicate is called multiple times, it is necessary to "daisy chain" temporary vari...

Let's say you want to test method which throws an exception class Car { /** * @throws \Exception */ public function drive() { throw new \Exception('Useful message', 1); } } You can do that by enclosing the method call into a try/catch block and making a...

To install the software: After the download completes, run the installer. For Windows, the installer executable file has the .exe extension. Double-click the installer file to run it. For Linux platforms, the installer file has the .sh extension. For these platforms, you need to make ...

To install the software: After the download completes, run the installer. The installer file has the .dmg extension. On the panel that opens double-click the package icon. The package has the .pkg extension. The installation wizard starts. Click Continue when the "This package will run a p...

To run the software: After the download of the platform-independent ZIP file completes, extract it to any folder on your system. Run the executable file located in the netbeans/bin directory. Accept the License Agreement. Click Next. The NetBeans IDE installation starts. Note: If a compatib...

A common mistake is to hide an indexed column inside a function call. For example, this can't be helped by an index: WHERE DATE(dt) = '2000-01-01' Instead, given INDEX(dt) then these may use the index: WHERE dt = '2000-01-01' -- if `dt` is datatype `DATE` This works for DATE, DATETIME, TIM...

Detailed instructions on getting cloudkit set up or installed.

// app.module.ts import { NgModule } from '@angular/core'; import { BrowserModule } from '@angular/platform-browser'; import { HttpModule } from '@angular/http'; import { MyRootComponent } from './app.component'; @NgModule({ declarations: [MyRootComponent], imports: [BrowserModule, Ht...

This example has two parts - some boilerplate steps for adding Castle Windsor to your WCF service, and then a simple, concrete example to show how we configure and use Windsor's container. That makes the example a little bit long. If you already understand using a DI container then you likely only ...

Prototype: aggregate(zeroValue, seqOp, combOp) Description: aggregate() lets you take an RDD and generate a single value that is of a different type than what was stored in the original RDD. Parameters: zeroValue: The initialization value, for your result, in the desired format. seqOp: ...

NIO appeared in Java 1.4 and introduced the concept of "Channels", which are supposed to be faster than regular I/O. Network-wise, the SelectableChannel is the most interesting as it allows to monitor different states of the Channel. It works in a similar manner as the C select() system ca...

It is very common to get a StackOverflowError error while calling recursive function. Scala standard library offers TailCall to avoid stack overflow by using heap objects and continuations to store the local state of the recursion. Two examples from the scaladoc of TailCalls import scala.util.cont...

C# allows using pointer variables in a function of code block when it is marked by the unsafe modifier. The unsafe code or the unmanaged code is a code block that uses a pointer variable. A pointer is a variable whose value is the address of another variable i.e., the direct address of the memory l...

The PATH environment variable is generally defined in ~/.bashrc or ~/.bash_profile or /etc/profile or ~/.profile or /etc/bash.bashrc (distro specific Bash configuration file) $ echo $PATH /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/usr/lib/jv...

a Character evaluates to true if it's value is not zero, false if zero assert ! new Character((char)0) assert ! new Character('\u0000Hello Zero Char'.charAt(0)) assert new Character('Hello'.charAt(0))

a Matcher evaluates to true if it can find at least one match, false if no match is found // a match is found => true assert 'foo' =~ /[a-z]/ // the regexp does not match fully => no match => false assert !( 'foo' ==~ /[a-z]/ ) // a match is found => true assert 'foo' =~ /o/ // no...

The evaluation of a closure is the evaluation of the result of the closure. All rules applies : if the closure returns a null , zero number or empty String, Collection, Map or Array it evaluates to false otherwise to true. // Closure return non zero number => true assert { 42 }() // closure ...

To remove a PATH from a PATH environment variable, you need to edit ~/.bashrc or ~/.bash_profile or /etc/profile or ~/.profile or /etc/bash.bashrc (distro specific) file and remove the assignment for that particular path. Instead of finding the exact assignment, you could just do a replacement in t...

Detailed instructions on getting apache-poi set up or installed.

<button class="btn btn-default" type="button">Default</button> <button class="btn btn-primary" type="button">Primary</button> <button class="btn btn-success" type="button">Success</button> <button c...