Tutorial by Examples: p

Pattern synonyms are abstractions of patterns similar to how functions are abstractions of expressions. For this example, let's look at the interface Data.Sequence exposes, and let's see how it can be improved with pattern synonyms. The Seq type is a data type that, internally, uses a complicated r...

A real world example using a scientific experiment where certain routines are performed on different types of tissue. The class contains two functions by default to get the tissue or routine separately. In a later version we have then adapted it using a new class to add a function that gets both. Th...

Visitor pattern allows you to add new operations or methods to a set of classes without modifying the structure of those classes. This pattern is especially useful when you want to centralise a particular operation on an object without extending the object Or without modifying the object. UML diag...

Lets assume that in your current codebase, there exists MyLogger interface like so: interface MyLogger { void logMessage(String message); void logException(Throwable exception); } Lets say that you've created a few concrete implementations of these, such as MyFileLogger and MyConsol...

Database connections are set up using the CF Administrator tool. See Database Connections for how to connect a datasource. To execute queries all you need is the <cfquery> tag. The <cfquery> tag connects to and opens the database for you, all you need to do is supply it with the name of...

create destination with <a id="destinationLinkName"></a> link to destination [link text](#destinationLinkName)

Write-Host "Hello World" Introduction to PowerShell

Lambda expressions are similar to anonymous functions in other languages. Lambda expressions are open formulas which also specify variables which are to be bound. Evaluation (finding the value of a function call) is then achieved by substituting the bound variables in the lambda expression's body, ...

[TimeStamp] attribute can be applied to only one byte array property in a given Entity class. Entity Framework will create a non-nullable timestamp column in the database table for that property. Entity Framework will automatically use this TimeStamp column in concurrency check. using System.Compon...

Function scope is the special scope for labels. This is due to their unusual property. A label is visible through the entire function it is defined and one can jump (using instruction gotolabel) to it from any point in the same function. While not useful, the following example illustrate the point: ...

What's between \Q and \E is treated as normal characters #!/usr/bin/perl my $str = "hello.it's.me"; my @test = ( "hello.it's.me", "hello/it's!me", ); sub ismatched($) { $_[0] ? "MATCHED!" : "DID NOT MATCH!" } my @match = ( ...

using System; using System.Runtime.InteropServices; namespace ComLibrary { [ComVisible(true)] public interface IMainType { int GetInt(); void StartTime(); int StopTime(); } [ComVisible(true)] [ClassInterface(ClassInterfaceType.N...

Services declaration : # src/Acme/YourBundle/Resources/config/services.yml services: my_service: class: Acme\YourBundle\Service\MyService arguments: ["@doctrine", "%some_parameter%", "@another_service"] another_service: class: Ac...

el-get is an open source package management system for GNU Emacs. el-get works with melpa, as well as with many common version control systms. Its documentation includes a simple self-installer for your .emacs: (unless (require 'el-get nil t) (url-retrieve "https://raw.github.com/dim...

Basically, parfor is recommended in two cases: lots of iterations in your loop (i.e., like 1e10), or if each iteration takes a very long time (e.g., eig(magic(1e4))). In the second case you might want to consider using spmd . The reason parfor is slower than a for loop for short ranges or fast itera...

We can wrap a class decorator with another function to allow customization: function addMetadata(metadata: any) { return function log(target: any) { // Add metadata target.__customMetadata = metadata; // Return target return target; ...

The regular composition works for unary functions. In the case of binary, we can define (f .: g) x y = f (g x y) -- which is also = f ((g x) y) = (f . g x) y -- by definition of (.) = (f .) (g x) y = ((f .) . g) x y Thus,...

Extensions can add new subscripts to an existing type. This example gets the character inside a String using the given index: 2.2 extension String { subscript(index: Int) -> Character { let newIndex = startIndex.advancedBy(index) return self[newIndex] } } var my...

Install webpack-dev-middleware via npm npm i -D webpack-dev-middleware webpack-hot-middleware Modify webpack.config.js Add webpack-hot-middleware/client to each items defined in "entry" Add new webpack.HotModuleReplacementPlugin() to "plugins" module.export...

PhpStorm can be very slow in large files as its performing so many inspections. One quick and easy way to speed up PhpStorm is to render using OpenGL. Previously in a 5000 line file it would give the 'eye' symbol in the top right for a long time before changing to a tick (or red/yellow box). After O...