Opa - Programming language

Opa is a programming language created in 2011.

#121on PLDB

13Years Old

76Repos

Download source code:

git clone https://github.com/MLstate/opalang

Opa is an open-source programming language for developing scalable web applications. It can be used for both client-side and server-side scripting, where complete programs are written in Opa and subsequently compiled to Nodejs on the server and JavaScript on the client, with the compiler automating all communication between the two. Opa implements strong, static typing, which can be helpful in protecting against security issues such as SQL injections and cross-site scripting attacks. Read more on Wikipedia...

Opa website
Opa Wikipedia page
Opa is developed on GitHub and has 1,227 stars
Opa docs
There are at least 76 Opa repos on GitHub
Opa first developed in https://github.com/MLstate
Opa on Twitter
The Google BigQuery Public Dataset GitHub snapshot shows 50 users using Opa in 58 repos on GitHub
Explore Opa snippets on Rosetta Code
Pygments supports syntax highlighting for Opa
GitHub supports syntax highlighting for Opa
opalang.org was registered in 2010
See also: (12 related languages)Linux, OCaml, Erlang, JavaScript, JQuery, HTML, MongoDB, PostgreSQL, SQL, Dart, Haxe, CoffeeScript

Example from hello-world:

jlog("Hello World")

Example from Linguist:

/**
 * To compile & run on port 8080:
 * opa hello_syntax1.opa --
 */
server = Server.one_page_server(
   "Hello, world",
   -> (<h1>Hello, world</h1>)
)

Example from Wikipedia:

Server.start(Server.http,
  { title: "Hello"
  , page: function() { <h1>Hello, web!</h1> }
  }
)

Opa Keywords

and as begin case client css database db do else end external forall function if import match module or package parser rec server then type val with xml_parser

Language features

Feature	Supported	Token	Example
Binary Literals	✓
Integers	✓
Floats	✓
Hexadecimals	✓
Octals	✓
Conditionals	✓
Functions	✓
Strings	✓	"	"Hello world"
Comments	✓		/* A comment */
MultiLine Comments	✓	/* */	/* A comment */
Print() Debugging	✓	jlog
Type Inference	✓
Semantic Indentation	X