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The nodemon package makes it possible to automatically reload your program when you modify any file in the source code. Installing nodemon globally npm install -g nodemon (or npm i -g nodemon) Installing nodemon locally In case you don't want to install it globally npm install --save-dev nodemo...

A macro can produce different outputs against different input patterns: /// The `sum` macro may be invoked in two ways: /// /// sum!(iterator) /// sum!(1234, iterator) /// macro_rules! sum { ($iter:expr) => { // This branch handles the `sum!(iterator)` case $iter.f...

In $e:expr, the expr is called the fragment specifier. It tells the parser what kind of tokens the parameter $e is expecting. Rust provides a variety of fragment specifiers to, allowing the input to be very flexible. SpecifierDescriptionExamplesidentIdentifierx, foopathQualified namestd::collection...

Exporting a macro to allow other modules to use it: #[macro_export] // ^~~~~~~~~~~~~~~ Think of it as `pub` for macros. macro_rules! my_macro { (..) => {..} } Using macros from other crates or modules: #[macro_use] extern crate lazy_static; // ^~~~~~~~~~~~ Must add this in ord...

(All of these are unstable, and thus can only be used from a nightly compiler.) log_syntax!() #![feature(log_syntax)] macro_rules! logged_sum { ($base:expr) => { { log_syntax!(base = $base); $base } }; ($a:expr, $($rest:expr),+) => { { log_syntax!(a = $...

docker inspect supports Go Templates via the --format option. This allows for better integration in scripts, without resorting to pipes/sed/grep traditional tools. Print a container internal IP: docker inspect --format '{{ .NetworkSettings.IPAddress }}' 7786807d8084 This is useful for direct ne...

extern crate serde; extern crate serde_json; macro_rules! enum_str { ($name:ident { $($variant:ident($str:expr), )* }) => { #[derive(Clone, Copy, Debug, Eq, PartialEq)] pub enum $name { $($variant,)* } impl ::serde::Serialize for $name {...

INSERT INTO will append to the table or partition, keeping the existing data intact. INSERT INTO table yourTargetTable SELECT * FROM yourSourceTable; If a table is partitioned then we can insert into that particular partition in static fashion as shown below. INSERT INTO TABLE yourTarge...

Say we have an enum DayOfWeek: enum DayOfWeek { SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY; } An enum is compiled with a built-in static valueOf() method which can be used to lookup a constant by its name: String dayName = DayOfWeek.SUNDAY.name(); assert dayName.equal...

The <label> element is used to reference a form action element. In the scope of User Interface it's used to ease the target / selection of elements like Type radio or checkbox. <label> as wrapper It can enclose the desired action element <label> <input type="checkb...

Given a sequence of steps we use repeatedly, it's often handy to store it in a function. Pipes allow for saving such functions in a readable format by starting a sequence with a dot as in: . %>% RHS As an example, suppose we have factor dates and want to extract the year: library(magrittr) ...

This topic specifically talks about UTF-8 and considerations for using it with a database. If you want more information about using databases in PHP then checkout this topic. Storing Data in a MySQL Database: Specify the utf8mb4 character set on all tables and text columns in your database. ...

JSFiddle: https://jsfiddle.net/UnsungHero97/80qod7aL/ HTML <div class="box_shadow"></div> CSS .box_shadow { -webkit-box-shadow: 0px 0px 10px -1px #444444; -moz-box-shadow: 0px 0px 10px -1px #444444; box-shadow: 0px 0px 10px -1px #444444; }

HTML <div class="box_shadow"></div> CSS .box_shadow { background-color: #1C90F3; width: 200px; height: 100px; margin: 50px; -webkit-box-shadow: inset 0px 0px 10px 0px #444444; -moz-box-shadow: inset 0px 0px 10px 0px #444444; box-shadow: inse...

JSFiddle: https://jsfiddle.net/UnsungHero97/80qod7aL/2/ HTML <div class="box_shadow"></div> CSS .box_shadow { background-color: #1C90F3; width: 200px; height: 100px; margin: 50px; } .box_shadow:after { content: ""; width: 190px; height: ...

If you need to match characters that are a part of the regular expression syntax you can mark all or part of the pattern as a regex literal. \Q marks the beginning of the regex literal. \E marks the end of the regex literal. // the following throws a PatternSyntaxException because of the un-close...

The following code will print the arguments to the program, and the code will attempt to convert each argument into a number (to a long): #include <stdlib.h> #include <stdio.h> #include <errno.h> #include <limits.h> int main(int argc, char* argv[]) { for (int ...

Python 2.x2.7 To import a module through a function call, use the importlib module (included in Python starting in version 2.7): import importlib random = importlib.import_module("random") The importlib.import_module() function will also import the submodule of a package directly: c...

-- Create an index for column 'name' in table 'my_table' CREATE INDEX idx_name ON my_table(name);

A unique index prevents the insertion of duplicated data in a table. NULL values can be inserted in the columns that form part of the unique index (since, by definition, a NULL value is different from any other value, including another NULL value) -- Creates a unique index for column 'name' in tabl...