Tutorial by Examples: ast

The result of a reinterpret_cast from one function pointer type to another, or one function reference type to another, is unspecified. Example: int f(); auto fp = reinterpret_cast<int(*)(int)>(&f); // fp has unspecified value C++03 The result of a reinterpret_cast from one object poi...

It is common to need a base style that defines properties/values shared between multiple styles belonging to the same control, especially for something like TextBlock. This is accomplished by using the BasedOn property. Values are inherited and then can be overridden. <Style x:Key="BaseText...

In R, data objects are manipulated using named data structures. The names of the objects might be called "variables" although that term does not have a specific meaning in the official R documentation. R names are case sensitive and may contain alphanumeric characters(a-z,A-z,0-9), the dot...

The Repeat command, executed with the dot or period key (.), is more useful than it first appears. Once learned, you will find yourself using it often. Command:Description.Repeat the last change10.Repeat the last change 10 times So then, for a very simple example, if you make a change to line 1 by...

In Vim, these operations are handled differently from what you might be used to in almost any other modern editor or word processor (Ctrl-C, Ctrl-X, Ctrl-V). To understand, you need to know a little about registers and motions. Note: this section will not cover Visual Mode copying and cutting or ra...

Building project dependencies can sometimes be a tedious task. Instead of publishing a package version to NPM and installing the dependency to test the changes, use npm link. npm link creates a symlink so the latest code can be tested in a local environment. This makes testing global tools and proje...

A downcast can be used to make use of a subclass's code and data inside of a function taking a parameter of its superclass. class Rat { var color = "white" } class PetRat: Rat { var name = "Spot" } func nameOfRat(🐭: Rat) -> String { guard let petRat = ...

A common use of macros is to create templates for data structures which obey common rules but may contain different fields. By writing a macro, you can allow the detailed configuration of the data structure to be specified without needing to repeat boilerplate code, nor to use a less efficient struc...

As the characters/digits can be anywhere within the string, we require lookaheads. Lookaheads are of zero width meaning they do not consume any string. In simple words the position of checking resets to the original position after each condition of lookahead is met. Assumption :- Considering non-wo...

This can be done with a bit of modification in the above regex ^(?=.{10,}$)(?=(?:.*?[A-Z]){2})(?=.*?[a-z])(?=(?:.*?[0-9]){2}).*$ or ^(?=.{10,}$)(?=(?:.*[A-Z]){2})(?=.*[a-z])(?=(?:.*[0-9]){2}).* Let's see how a simple regex ^(?=(?:.*?[A-Z]){2}) works on string abcAdefD Image Credit :- ht...

To create a custom standalone Gradle plug-in using java (you can also use Groovy) you have to create a structure like this: plugin |-- build.gradle |-- settings.gradle |-- src |-- main | |-- java | |-- resources | |-- META-INF | |-- gradle-plugins ...

In order to compare query sequences against reference sequences, you must create a blastdb of your reference(s). This is done using makeblastdb which is included when you install blast. makeblastdb -in <input fasta> -dbtype nucl -out <label for database> So if you had a file referen...

You can extract fasta sequence from a blastdb constructed from a fasta file using blastdbcmd which should be installed when you install makeblastdb. blastdbcmd -entry all -db <database label> -out <outfile> If you had a database called my_database which contained the files my_databas...

apt-get install ncbi-blast+ You can check the version that will be installed in advance here: http://packages.ubuntu.com/xenial/ncbi-blast+

Unlike most other JavaScript objects, symbols are not automatically converted into a string when performing concatenation. let apple = Symbol('Apple') + ''; // throws TypeError! Instead, they have to be explicitly converted into a string when necessary, (for example, to get a textual description...

When pasting text through a terminal emulator, the auto-indent feature may destroy the indentation of the pasted text. For example: function () { echo 'foo' echo 'bar' echo 'baz' } will be pasted as: function () { echo 'foo' echo 'bar' echo 'baz' ...

This example updates last write time of a huge number of files (using System.IO.Directory.EnumerateFiles instead of System.IO.Directory.GetFiles()). Optionally you can specify a search pattern (default is "*.*" and eventually search through a directory tree (not only the specified director...

Having example type like this: public TestClass { public static string StaticPublicField = "StaticPublicFieldValue"; } We can retrieve value of StaticPublicField: var fieldExpr = Expression.Field(null, typeof(TestClass), "StaticPublicField"); var labmda = Expression....

The :last-of-type selects the element that is the last child, of a particular type, of its parent. In the example below, the css selects the last paragraph and the last heading h1. p:last-of-type { background: #C5CAE9; } h1:last-of-type { background: #CDDC39; } <div class="c...

C++14 It is often useful to define classes or structures that have a variable number and type of data members which are defined at compile time. The canonical example is std::tuple, but sometimes is it is necessary to define your own custom structures. Here is an example that defines the structure ...