Erlang - Programming language

Erlang is an open source programming language created in 1986 by Joe Armstrong and Robert Virding and Mike Williams.

#31on PLDB

40Years Old

29kRepos

Download source code:

git clone https://github.com/erlang/otp

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Erlang ( ER-lang) is a general-purpose, concurrent, functional programming language, as well as a garbage-collected runtime system. The term Erlang is used interchangeably with Erlang/OTP, or OTP, which consists of the Erlang runtime system, a number of ready-to-use components mainly written in Erlang, and a set of design principles for Erlang programs. The Erlang runtime system is known for its designs that are well suited for systems with the following characteristics: Distributed Fault-tolerant Soft real-time, Highly available, non-stop applications Hot swapping, where code can be changed without stopping a system. Read more on Wikipedia...

Tags: programming language
Erlang is developed on GitHub and has 11,203 stars
There are at least 28,645 Erlang repos on GitHub
Early development of Erlang happened in Ericsson
Erlang is written in Erlang, C, Markdown, Make, JSON, Bourne shell, C++, XML, Java, Elixir, XSD, Assembly language, Python, HTML, SQL, Perl, Lisp, D, M4, YAML, sed, Bash, Dockerfile, Ini, DTD, CSS, JavaScript, Diff, SVG, XSLT, plantuml
The Google BigQuery Public Dataset GitHub snapshot shows 9k users using Erlang in 15k repos on GitHub
Check out the 306 Erlang meetup groups on Meetup.com.
There are 9,057 members in the Erlang subreddit
There are 618 Project Euler users using Erlang
In the 2021 StackOverflow developer survey Erlang programmers reported a median salary of $80,077. 1% of respondents reported using Erlang. 651 programmers reported using Erlang, and 1,379 said they wanted to use it
Explore Erlang snippets on Rosetta Code
Erlang on HOPL
Erlang ranks #49 in the TIOBE Index
Erlang Ubuntu package
ANTLR grammar for Erlang
Erlang LSP implementation
CodeMirror package for syntax highlighting Erlang
Pygments supports syntax highlighting for Erlang
GitHub supports syntax highlighting for Erlang
Erlang appears in the Quine Relay project
Learn Erlang on exercism.
PLDB has 2 Jupyter Kernels for Erlang: github.com, github.com
There is a central package repository for Erlang
Indeed.com has 183 matches for "erlang engineer".
erlang.org was registered in 1998
See also: (17 related languages) Prolog, Smalltalk, PLEX, F#, Clojure, Rust, Scala, Opa, Elixir, Dart, Oz, Java, ASCII, Occam, CSP, LFE, Lisp
15 PLDB concepts link to Erlang: Ace Editor, Alpaca, Axio, Caramel, CouchDB, cuneiform, DRAKON, Elixir, Erlang, Gleam, hamler, mal, Pygments, Reia, Sophia

Example from Compiler Explorer:

-module(square).
-export([square/1]).

square(A) -> A*A.

Example from Riju:

-module(main).
-export([main/0]).

main() ->
    io:fwrite("Hello, world!\n").

Example from hello-world:

-module(erlang_hw).
-export([start/0]).

start() ->
  io:format("Hello World~n").

Example from the Hello World Collection:

%% Hello World in Erlang

-module(hello).

-export([hello/0]).

hello() ->
   io:format("Hello World!~n", []).

Example from Linguist:

#!/usr/bin/env escript
-export([main/1]).

main([]) -> io:format("Hello, World!~n").

Example from Wikipedia:

%% Second version
  -module(counter).
  -export([start/0, codeswitch/1]).

  start() -> loop(0).

  loop(Sum) ->
    receive
       {increment, Count} ->
          loop(Sum+Count);
       reset ->
          loop(0);
       {counter, Pid} ->
          Pid ! {counter, Sum},
          loop(Sum);
       code_switch ->
          ?MODULE:codeswitch(Sum)
    end.

  codeswitch(Sum) -> loop(Sum).

Erlang Keywords

after and andalso begin bnot bor bsl bsr bxor case catch cond div end fun if let not of or orelse receive rem try when xor

Language features

Feature	Supported	Example	Token
Standard Library	✓	io:format("Hello, World!~n").
Integers	✓	% [+-]?(?:[2-9]\|[12][0-9]\|3[0-6])#[0-9a-zA-Z]+
Floats	✓	% [+-]?\d+.\d+
Conditionals	✓
Functions	✓
Print() Debugging	✓		io:format
Message Passing	✓
Line Comments	✓	% A comment	%
Macros	✓	-define(Const, Replacement). -define(Func(Var1,...,VarN), Replacement).
hasExports	✓	-export([start/0, codeswitch/1]).
File Imports	✓	-include("my_records.hrl"). -include("incdir/my_records.hrl"). -include("/home/user/proj/my_records.hrl"). -include("$PROJ_ROOT/my_records.hrl"). -include_lib("kernel/include/file.hrl").
Directives	✓	-define(TIMEOUT, 200). ... call(Request) -> server:call(refserver, Request, ?TIMEOUT). -undef(Macro).
Comments	✓	% A comment
Shebang	✓	#!/usr/bin/env escript
Strings	✓	"hello world"
Case Insensitive Identifiers	X
Semantic Indentation	X
MultiLine Comments	X