Tutorial by Examples: u

Partial Application and Currying

Technically, Ruby doesn't have functions, but methods. However, a Ruby method behaves almost identically to functions in other language: def double(n) n * 2 end This normal method/function takes a parameter n, doubles it and returns the value. Now let's define a higher order function (or met...

Ruby Language • Blocks and Procs and Lambdas

Multiple Producers and Consumers Sharing the same buffer

This example shows multiple producers and consumers sharing the same buffer. Protected entries in Ada implement a queue to handle waiting tasks. The default queuing policy is First In First Out. ------------------------------------------------------------------ -- Multiple producers and consumers ...

ada • Implementing the producer-consumer pattern

Opening a URL with Default Browser

To simply open a URL, use the webbrowser.open() method: import webbrowser webbrowser.open("http://stackoverflow.com") If a browser window is currently open, the method will open a new tab at the specified URL. If no window is open, the method will open the operating system's default b...

Python Language • Webbrowser Module

Opening a URL with Different Browsers

The webbrowser module also supports different browsers using the register() and get() methods. The get method is used to create a browser controller using a specific executable's path and the register method is used to attach these executables to preset browser types for future use, commonly when mu...

Python Language • Webbrowser Module

Installation or Setup

Detailed instructions on getting activemq set up or installed.

activemq • Getting started with activemq

Multi-line statements

The :{ instruction begins multi-line mode and :} ends it. In multi-line mode GHCi will interpret newlines as semicolons, not as the end of an instruction. ghci> :{ ghci| myFoldr f z [] = z ghci| myFoldr f z (y:ys) = f y (myFoldr f z ys) ghci| :} ghci> :t myFoldr myFoldr :: (a -> b -&g...

Haskell Language • Using GHCi

Routing URLs

With Flask, URL routing is traditionally done using decorators. These decorators can be used for static routing, as well as routing URLs with parameters. For the following example, imagine this Flask script is running the website www.example.com. @app.route("/") def index(): return ...

Python Language • Flask

The Request Object

The request object provides information on the request that was made to the route. To utilize this object, it must be imported from the flask module: from flask import request URL Parameters In previous examples request.method and request.form were used, however we can also use the request.args...

Python Language • Flask

Individual Shader Object Compilation in C++

The traditional GLSL compilation model involves compiling code for a shader stage into a shader object, then linking multiple shader objects (covering all of the stages you want to use) into a single program object. Since 4.2, program objects can be created that have only one shader stage. This met...

opengl • Shader Loading and Compilation

Installing Atom on Linux

Installing from a package Debian, Ubuntu, etc. $ sudo dpkg -i atom-amd64.deb $ sudo apt-get -f install RedHat Enterprise, CentOS, Oracle Linux, Scientific Linux, etc. $ sudo yum install -y atom.x86_64.rpm Fedora (DNF package manager) $ sudo dnf install -y atom.x86_64.rpm SUSE (Zypp pac...

atom-editor • Installation and Setup

How to update packages with yum

Yellowdog Updater, Modified, one of the last remaining vestiges of Yellow Dog Linux, is the package manager used by Red Hat, Fedora, and CentOS systems and their derivatives. It can handle the installation and removal of software packaged as rpms for these Linux distributions. Below are some simple...

GNU/Linux • Package Managers

Changing drive without CD /D

Pushd "D:\Foo" Dir Popd Pushd will change the directory to the directory following (in this case D:\Foo. Popd returns back to the original directory.

batch-file • Changing Directories and Listing their Contents

Hive UDF to trim the given string.

package MyHiveUDFs; import org.apache.commons.lang.StringUtils; import org.apache.hadoop.hive.ql.exec.UDF; import org.apache.hadoop.io.Text; public class Strip extends UDF { private Text result = new Text(); public Text evaluate(Text str) { if(str == null) { return null; } resul...

hive • Hive User Defined Functions (UDF's)

install the popular Clonezilla to clone a Mac OS hard drive (basic usage)

Naturally, being able to install hard drive cloning utilities can be an important aspect of installing and maintaining your operating system. Getting set up with Clonezilla is surprisingly less straightforward than I'd have expected. The wealth of options, while valuable, also makes each part of id...

operating-system • Getting started with operating-system

Types of

Make sure you link the Angular and Angular Material libraries! index.html: <html ng-app="mdButtonApp"> <head>  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.8/angular.min.js"></script&gt...

angular-material • md-button

Creating an icon button

This example will be using the class md-icon-button, which must be applied to <md-button> in order to get an icon button. It is also recommended to add an aria-label attribute to <md-button> for accessibility purpose or the ARIA provider will throw a warning that there is no aria-labe...

angular-material • md-button

Use generics to enhance type-safety

Let's take this example without using generics protocol JSONDecodable { static func from(_ json: [String: Any]) -> Any? } The protocol declaration seems fine unless you actually use it. let myTestObject = TestObject.from(myJson) as? TestObject Why do you have to cast the result to T...

Swift Language • Generics

Basic Query

/* Define a query named q1 for the Customer table */ DEFINE QUERY q1 FOR Customer. /* Open the query for all Customer records where the state is "tx" */ OPEN QUERY q1 FOR EACH Customer WHERE Customer.state ='TX'. ...

progress-4gl • Queries

Multi-Tables Query

This query will join three tables: Customer, Order and Orderline. The use of the OF statement as in childtable OF parenttable assumes that indexes are constructed in a specific way. That is the case in the sports2000-database. DEFINE QUERY q1 FOR Customer, Order, Orderline. OPEN QUERY q1 FOR EA...

progress-4gl • Queries

Using informats to read data

Informats are used to tell SAS how to read in the data and are identified with an informat statement. data test; infile test.csv; informat id $6. date mmddyy10. cost comma10.2 ; input @1 id @7 date @20 cost ; run; Informats and Format...

sas • SAS Formats