Tutorial by Examples: t

In the below example value in map $color-array is treated as list of pairs. SCSS Input $color-array:( black: #4e4e4e, blue: #0099cc, green: #2ebc78 ); @each $color-name, $color-value in $color-array { .bg-#{$color-name} { background: $color-value; } } ...

Due to very specific way of actor instantiation, injecting dependencies into an actor instance is not trivial. In order to intervene in actor instantiation and allow Spring to inject dependencies one should implement a couple of akka extensions. First of those is an IndirectActorProducer: import ak...

Labeling the alternatives inside a rule starting with the # operator tells ANTLR to generate listener methods for each label corresponding to the alternative. By specifying a label for each alternative in the following rule: // Rule type : int #typeInt | short #typeShort | long ...

Specifying the -gui command line option when running an ANTLR grammar in the test rig will result in a window popping up with a visual representation of the parse tree. For example: Given the following grammar: JSON.g4 /** Taken from "The Definitive ANTLR 4 Reference" by Terence Parr */...

#demo-element { background: @theme-color; color: contrast(@theme-color, black, white, 50%); } @theme-color: red; The above example will set the text color of the element as white if the background-color is dark and vice-versa. This is achieved using the contrast() color operation functi...

The presence of a tsconfig.json file indicates that the current directory is the root of a TypeScript enabled project. Initializing a TypeScript project, or better put tsconfig.json file, can be done through the following command: tsc --init As of TypeScript v2.3.0 and higher this will create t...

Due to the vulnerability caused by CSRF, it is generally considered a good practice to check for an AntiForgeryToken on all HttpPosts unless there is a good reason to not do it (some technical issue with the post, there is another authentication mechanism and/or the post does not mutate state like s...

For a 12hour time format one can use: ^(?:0?[0-9]|1[0-2])[-:][0-5][0-9]\s*[ap]m$ Where (?:0?[0-9]|1[0-2]) is the hour [-:] is the separator, which can be adjusted to fit your need [0-5][0-9] is the minute \s*[ap]m followed any number of whitespace characters, and am or pm If you need th...

Servant is a library for declaring APIs at the type-level and then: write servers (this part of servant can be considered a web framework), obtain client functions (in haskell), generate client functions for other programming languages, generate documentation for your web applications and m...

PresenceOf - Validates that a value is not null or empty string $validator->add('name', new \Phalcon\Validation\Validator\PresenceOf([ 'message' => 'The name is required' ])); Email - Checks if a value has a correct e-mail format $validator->add('email', new \Phalcon\Validation\Va...

In Tcl, a control structure is basically just another command. This is one possible implementation of a do ... while / do ... until control structure. proc do {body keyword expression} { uplevel 1 $body switch $keyword { while {uplevel 1 [list while $expression $body]} u...

2.1.3 1. Preview Different Devices There is a preview panel at the right of the android studio. In thispanel there is a button with device name with which you are previewing the UI of your app like this . Click on small dropdown indicator of this and a floating panel will appear with all the pr...

VB 14.0 introduces the ability to add comments after implicit line continuation. Dim number = From c As Char 'Comment In "dj58kwd92n4" 'Comment Where Char.IsNumber(c) 'Comment Select c 'Comment

Set mark in cursor location: C-space or C-@ Kill region (Cut): C-w Copy region to kill ring: M-w or Esc-w Yank (Paste) most recently killed: C-y Yank (Paste) next last killed: M-y or Esc-y Kill killis the command used by Emacs for the deletion of ...

It forces you to explicitly declare all variables. What is the difference between explicitly declaring and implicitly declaring a variable? Explicitly declaring a variable: Dim anInteger As Integer = 1234 Implicitly declaring a variable: 'Did not declare aNumber using Dim aNumber = 1234 C...

Document level It is on by default, but you can have an extra layer of protection by placing Option Explicit On at the top of the code file. The option will apply to the whole document. Project level You can switch it on via the menu in Visual Studio: Project > [Project] Properties > Com...

Use the task dependencies. Depending on how your modules are set up, it may be either ./gradlew dependencies or to see the dependencies of module app use ./gradlew :app:dependencies The example following build.gradle file dependencies { compile 'com.android.support:design:23.2.1' compile...

Using the System.String.Replace method, you can replace part of a string with another string. string s = "Hello World"; s = s.Replace("World", "Universe"); // s = "Hello Universe" All the occurrences of the search string are replaced. This method can al...

The System.String class supports a number of methods to convert between uppercase and lowercase characters in a string. System.String.ToLowerInvariant is used to return a String object converted to lowercase. System.String.ToUpperInvariant is used to return a String object converted to upper...

The System.String.Join method allows to concatenate all elements in a string array, using a specified separator between each element: string[] words = {"One", "Two", "Three", "Four"}; string singleString = String.Join(",", words); // singleString =...