Tutorial by Examples: t

Fragments are reusable parts of lexer rules which cannot match on their own - they need to be referenced from a lexer rule. INTEGER: DIGIT+ | '0' [Xx] HEX_DIGIT+ ; fragment DIGIT: [0-9]; fragment HEX_DIGIT: [0-9A-Fa-f];

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...

A lexer action is a block of arbitrary code in the target language surrounded by {...}, which is executed during matching: IDENTIFIER: [A-Z]+ { log("matched rule"); }; A semantic predicate is a block of arbitrary code in the target language surrounded by {...}?, which evaluates to a bo...

if we want to change the Controllers directory we need: Move and/or rename the default Controllers directory where we want it. For example from app/Http/Controllers to app/Controllers Update all the namespaces of the files inside the Controllers folder, making they adhere to the new path, re...

There are several ways to insert data: Using the DB Facade public function run() { DB::table('users') ->insert([ 'name' => 'Taylor', 'age' => 21 ]); } Via Instantiating a Model public function run() { $user = new User; $us...

Within your DatabaseSeeder class you are able to call other seeders $this->call(TestSeeder::class) This allows you to keep one file where you can easily find your seeders. Keep in mind that you need to pay attention to the order of your calls regarding foreign key constraints. You can't refe...

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...

# make this routine available outside this translation unit .globl string_to_integer string_to_integer: # function prologue push %ebp mov %esp, %ebp push %esi # initialize result (%eax) to zero xor %eax, %eax # fetch pointer to the string mov 8(%ebp), %e...

Disclaimer: the examples presented here are only for the purpose of showing the use of abstract classes and inheritance and may not necessarily be of a practical use. Also, there is no sich thing as polymorphic in MATLAB and therefore the use of abstract classes is limited. This example is to show w...

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...

Methods may declared as friends as well as functions: class Accesser { public: void private_accesser(); }; class PrivateHolder { public: PrivateHolder(int val) : private_value(val) {} friend void Accesser::private_accesser(); private: int private_value; }; void Access...

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. ...

This is a protected and non-static method of the Object class. This method is used to perform some final operations or clean up operations on an object before it gets removed from the memory. According to the doc, this method gets called by the garbage collector on an object when garbage collecti...

Fast and short way to extract extension from file name in JavaScript will be: function get_extension(filename) { return filename.slice((filename.lastIndexOf('.') - 1 >>> 0) + 2); } It works correctly both with names having no extension (e.g. myfile) or starting with . dot (e.g. .h...

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...

function assign(obj, prop, value) { if (typeof prop === 'string') prop = prop.split('.'); if (prop.length > 1) { var e = prop.shift(); assign(obj[e] = Object.prototype.toString.call(obj[e]) === '[object Object]' ? obj[e] ...

Use DOMContentLoaded when the <script> code interacting with DOM is included in the <head> section. If not wrapped inside the DOMContentLoaded callback, the code will throw errors like Cannot read something of null document.addEventListener('DOMContentLoaded', function(event) { ...

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 ...