Erlang programming language
Erlang programming language[edit]
Erlang is a programming language designed for building concurrent, fault-tolerant systems. Developed at Ericsson in the late 1980s, Erlang gained popularity for its ability to handle distributed and real-time applications.
Features[edit]
- Concurrency
- Fault tolerance
- Immutable data
- Pattern matching
- Hot code swapping
- Distributed computing
- Functional programming
- Message passing
- OTP (Open Telecom Platform)
History[edit]
Erlang was created by Joe Armstrong, Robert Virding, and Mike Williams at Ericsson to improve the efficiency and reliability of telecommunication systems. It was first released as a proprietary language in 1986 and later open-sourced in 1998.
Syntax[edit]
Erlang blends functional and imperative programming styles. Its syntax is compact and uses pattern matching extensively. The following "Hello, World!" example demonstrates the basic syntax of Erlang:
-module(hello_world).
-export([hello/0]).
hello() ->
io:format("Hello, World!~n").
Concurrency[edit]
Concurrency is a fundamental feature in Erlang. It is achieved through lightweight processes known as Erlang processes. These processes can communicate via message passing, allowing for efficient and concurrent programming.
-module(concurrency_example).
-export([start/0, worker/1]).
start() ->
Pid = spawn(?MODULE, worker, [5]),
Pid ! {self(), double},
receive
{Pid, Result} -> io:format("Doubled value: ~w~n", [Result])
end.
worker(N) ->
receive
{From, double} -> From ! {self(), N * 2}
end.
Fault Tolerance[edit]
Another key aspect of Erlang is its built-in fault-tolerant capabilities. By using supervisors and behaviors from OTP, Erlang applications can automatically recover from failures and continue running without interruptions.
-module(fault_tolerance_example).
-export([start/0, worker/0, crash/0]).
start() ->
{ok, Pid} = supervisor:start_link({local, ?MODULE}),
{ok, _} = supervisor:start_child(Pid, [?MODULE, worker, []]),
io:format("Supervisor started.~n").
worker() ->
io:format("Worker process started.~n"),
loop().
crash() ->
exit(crash).
loop() ->
receive
_ -> loop()
end.
Libraries and Frameworks[edit]
Erlang provides a rich ecosystem of libraries and frameworks. Some notable ones include:
- Erlang/OTP: The Erlang/OTP platform provides a comprehensive set of libraries, tools, and design principles to build scalable and fault-tolerant systems.
- Cowboy: A small, fast, and modern HTTP server for Erlang/OTP, suitable for building web applications and RESTful APIs.
- Riak: A distributed NoSQL database written in Erlang, designed to handle large-scale, fault-tolerant applications.
- Elixir: A dynamic, functional language built on top of Erlang that brings a more approachable syntax and powerful metaprogramming capabilities to the Erlang ecosystem.