Erlang (programming language)

For other uses, see erlang (disambiguation).

erlang is a general-purpose, functional computer programming language which shares some syntax with prolog. It was designed specificly to do parallel programming. which is used than twenty years after its creation. erlang was developed in 1987 by Joe Armstrong and others (then of Ericsonn) for use to program telephone networks. Ref: Joe Armstrong (2003). "Making reliable distributed systems in the presence of software errors". Ph.D. Dissertation. http://www.erlang.org/download/armstrong_thesis_2003.pdf New versions are released by Ericsson on a yearly basis. At present there is increased interest in parallel programming languages because of the spread of multicore microprocessor based personal computers.

Syntax

Hello World

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

start() ->
   io:format("Hello, world!\n").

Analysis of the example

The Hello World program (see above) appears in many programming languages books and articles as a cursory introduction into a language's syntax. It was introduced in the book The C Programming Language.

-module(hello) tells the compiler to create a new module(library) called hello. The code tells us the file name for this code: hello.erl.

-export([start/0]). exports a function named start with 0 arguments to the world outside of this module called hello.

start() -> tells the compiler that there is a function named start() with no arguments.

io:format("Hello, world!\n"). will make the program output Hello, world! and a new line (\n) on the screen.

See also

• prolog
• scheme