Tutorial by Examples: u

Send a 304 Not Modified response status from the server send in response to a client request that contains headers If-Modified-Since and If-None-Match, if the request resource hasn’t changed. For example if a client request for a web page includes the header If-Modified-Since: Fri, 22 Jul 2016 14:3...

In normal mode, move the cursor to any word then press * to search forwards for the next occurrence of the word under the cursor, or press # to search backwards. * or # search for the exact word under the cursor: searching for big would only find big and not bigger. Under the hood, Vim uses a sim...

The :global command already has its own topic: The global command

ANTLR contains a testing tool in its runtime library, this tool can be used to display information detailing how the parsing is performed to match input against defined rules in your grammar file. To use this tool contained within the ANTLR jar file you should setup your systems classpath to allow ...

Lexer rules define token types. Their name has to start with an uppercase letter to distinguish them from parser rules. INTEGER: [0-9]+; IDENTIFIER: [a-zA-Z_] [a-zA-Z_0-9]*; OPEN_PAREN: '('; CLOSE_PAREN: ')'; Basic syntax: SyntaxMeaningAMatch lexer rule or fragment named AA BMatch A follow...

When tokens like '{' are used in a parser rule, an implicit lexer rule will be created for them unless an explicit rule exists. In other words, if you have a lexer rule: OPEN_BRACE: '{'; Then both of these parser rules are equivalent: parserRule: '{'; parserRule: OPEN_BRACE; But if the OPE...

Several lexer rules can match the same input text. In that case, the token type will be chosen as follows: First, select the lexer rule which matches the longest input If the text matches an implicitly defined token (like '{'), use the implicit rule If several lexer rules match the same input l...

Functions within a class can be overloaded for when they are accessed through a cv-qualified reference to that class; this is most commonly used to overload for const, but can be used to overload for volatile and const volatile, too. This is because all non-static member functions take this as a hi...

A class or a structure may declare any function it's friend. If a function is a friend of a class, it may access all it's protected and private members: // Forward declaration of functions. void friend_function(); void non_friend_function(); class PrivateHolder { public: PrivateHolder(in...

In every applications life-cycle comes a day where it's components needs to be updated. Everyone knows the pain of updating every single dependency one-by-one. Well here you just need to issue the command: npm update (-g) If the "-g" is there then npm will update the global packages. ...

Fast and short way to format value of type Number as money, e.g. 1234567.89 => "1,234,567.89": var num = 1234567.89, formatted; formatted = num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,'); // "1,234,567.89" More advanced variant with support of any number o...

Here is an example of how to import a function that is defined in an unmanaged C++ DLL. In the C++ source code for "myDLL.dll", the function add is defined: extern "C" __declspec(dllexport) int __stdcall add(int a, int b) { return a + b; } Then it can be included into ...

""" ================================================================================ CREATE A 2 BY 2 GRID OF SUB-PLOTS WITHIN THE SAME FIGURE. ================================================================================ """ import matplotlib.pyplot as plt ...

""" ================================================================================ DRAW MULTIPLE LINES IN THE SAME PLOT ================================================================================ """ import matplotlib.pyplot as plt ...

Objective-C supports a special type called `instancetype that can only be used as type returned by a method. It evaluates to the class of the receiving object. Consider the following class hierarchy: @interface Foo : NSObject - (instancetype)initWithString:(NSString *)string; @end @interf...

UCanAccess is a pure Java JDBC driver that allows us to read from and write to Access databases without using ODBC. It uses two other packages, Jackcess and HSQLDB, to perform these tasks. Once it has been set up*, we can work with data in .accdb and .mdb files using code like this: import java.sq...

You can create and configure build types in the module-level build.gradle file inside the android {} block. android { ... defaultConfig {...} buildTypes { release { minifyEnabled true proguardFiles getDefaultProguar...

Gnuplot is a portable command-line driven graphing utility. This example will show how to setup gnuplot in the various platforms. Windows Download the latest version of the installer from gnuplot site. Run the downloaded file and allow it to run as administrator if requested On the ...

HTTP Basic Authentication provides a straightforward mechanism for authentication. Credentials are sent in plain text, and so is insecure by default. Successful authentication proceeds as follows. The client requests a page for which access is restricted: GET /secret The server responds with st...

Download your preferred version from Lightbend with curl: curl -O http://downloads.lightbend.com/scala/2.xx.x/scala-2.xx.x.tgz Unzip the tar file to /usr/local/share or /opt/bin: unzip scala-2.xx.x.tgz mv scala-2.xx.x /usr/local/share/scala Add the PATH to ~/.profile or ~/.bash_profile or ...