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Apache Subversion (SVN) is a universal and centralized open source version control system. Subversion is currently a project under Apache Software Foundation (ASF) and is licensed under the Apache License, Version 2.0. Subversion is designed to manage and control files and directories and track ...

Positive lookahead: (?=pattern) Negative lookahead: (?!pattern) Positive lookbehind: (?<=pattern) Negative lookbehind: (?<!pattern) Not supported by all regex engines. Additionally, many regex engines limit the patterns inside lookbehinds to fixed-length strings. For example the p...

Some languages require you to define ahead of time what kind of variable you're declaring. JavaScript doesn't do that; it will try to figure that out on its own. Sometimes this can create unexpected behavior. If we use the following HTML <span id="freezing-point">0</span> ...

undef # False '' # Defined, False 0 # Defined, Has Length, False '0' # Defined, Has Length, False Perl does not have a boolean data type, nor does it have any true and false keywords like many other languages. However, every scalar value will evaluate to true or false when evalu...

Pipe operators, available in magrittr, dplyr, and other R packages, process a data-object using a sequence of operations by passing the result of one step as input for the next step using infix-operators rather than the more typical R method of nested function calls. Note that the intended aim of p...

QML is an acronym that stands for Qt Meta-object Language. It is a declarative programming language that is part of the Qt framework. QML's main purpose is fast and easy creation of user interfaces for desktop, mobile and embedded systems. QML allows seamless integration of JavaScript, either dire...

Docker is an open-source project that automates the deployment of applications inside software containers. These application containers are similar to lightweight virtual machines, as they can be run in isolation to each other and the running host. Docker requires features present in recent linux...

Lua is minimalistic, lightweight and embeddable scripting language. It's being designed, implemented, and maintained by a team at PUC-Rio, the Pontifical Catholic University of Rio de Janeiro in Brazil. The mailing list is open to get involved. Common use-cases for Lua includes scripting video...

selector match partialFunction selector match {list of case alternatives) // This is most common form of the above ParameterDetailsselectorThe expression whose value is being pattern-matched.alternativesa list of case-delimited alternatives.

svn copy [BRANCH-FROM-URL] [BRANCH-TO-URL] -m <COMMIT-LOG-MESSAGE> svn copy [^/PATH-TO-BRANCH-FROM] [^/PATH-TO-BRANCH-TO] -m <COMMIT-LOG-MESSAGE> As you might have noticed, we use svn copy command to create branches, tags and shelves (we'll skip mentioning tags and shel...

ASDF - Another System Definition Facility ASDF is a tool for specifying how systems of Common Lisp software are made up of components (sub-systems and files), and how to operate on these components in the right order so that they can be compiled, loaded, tested, etc.

lua_State *L = lua_open(); // Create a new VM state; Lua 5.0 lua_State *L = luaL_newstate(); // Create a new VM state; Lua 5.1+ int luaL_dofile(lua_State *L, const char *filename); // Run a lua script with the given filename using the specified lua_State void luaL_openlibs(lua_State *L); // Lo...

var x int // declare variable x with type int var s string // declare variable s with type string x = 4 // define x value s = "foo" // define s value y := 5 // declare and define y inferring its type to int f := 4.5 // declare and define f inferring its type to float64 b := &quo...

ipairs(numeric_table) -- Lua table with numeric indices iterator pairs(input_table) -- generic Lua table iterator key, value = next(input_table, input_key) -- Lua table value selector table.insert(input_table, [position], value) -- insert specified value into the input table removed_value = ta...

A database snapshot is a read-only, static view of a SQL Server database which is transactionally consistent with the source database as of the moment of the snapshot's creation. A database snapshot always resides on the same server instance as its source database. As the source database is updat...

docker run [OPTIONS] IMAGE [COMMAND] [ARG...]