OCaml

OCaml is a programming language created in 1996 by Xavier Leroy.

OCaml ( oh-KAM-əl), originally named Objective Caml, is the main implementation of the programming language Caml, created by Xavier Leroy, Jérôme Vouillon, Damien Doligez, Didier Rémy, Ascánder Suárez and others in 1996. A member of the ML language family, OCaml extends the core Caml language with object-oriented programming constructs. OCaml's toolset includes an interactive top-level interpreter, a bytecode compiler, a reversible debugger, a package manager (OPAM), and an optimizing native code compiler. Read more on Wikipedia...

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the OCaml website
the OCaml Wikipedia page
file extensions for OCaml include ml, mli, eliom, eliomi, ml4, mll and mly
the OCaml team is on Twitter
Check out the 87 OCaml meetup groups on Meetup.com.
There are 219 Project Euler users using OCaml
Explore OCaml snippets on Rosetta Code
OCaml is listed on HOPL
OCaml appears in the TIOBE Index
There is an Ubuntu package for OCaml
Pygments supports syntax highlighting for OCaml
GitHub supports syntax highlighting for OCaml
OCaml appears in the Quine Relay project
There are 2 Jupyter Kernels for OCaml: 1,2
There is a central package repository for OCaml
ocaml.org was registered in 2000
See also: Occam, C, IA-32, SPARC, ARM, Unix, F#, Caml, Classroom Object Oriented Language, Standard ML, ATS, Elm, F*, Haxe, Opa, Rust, Scala, ML, Python, Perl, Java, C#, Fortran, JavaScript, JVM, PIC microcontroller, Emacs, Vim, OpenGL, Hack, PHP, iOS, Android, Coq, WebAssembly, Haskell
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Example code from Riju:

;;
print_string "Hello, world!\n"

Example code from hello-world:

print_string "Hello World\n"

Example code from the Hello World Collection:

(* Hello World in OCaml *)
print_string "Hello World!\n";;

Example code from Linguist:

(*
 * Copyright (c) 2013 Jeremy Yallop.
 *
 * This file is distributed under the terms of the MIT License.
 * See the file LICENSE for details.
 *)
let string_of format v =
  let buf = Buffer.create 100 in
  let fmt = Format.formatter_of_buffer buf in begin
    format fmt v;
    Format.pp_print_flush fmt ();
    Buffer.contents buf
  end

Example code from Wikipedia:

fun x_1 -> (x_1 *
     let y_3 =
         let y_2 = (x_1 * 1)
         in (y_2 * y_2)
     in (y_3 * y_3))

Keywords in OCaml

as assert begin class constraint do done downto else end exception external false for fun function functor if in include inherit initializer lazy let match method module mutable new object of open private raise rec sig struct then to true try type value val virtual when while with

Language features

Feature	Supported	Example	Token
Binary Literals	✓
Integers	✓
Floats	✓
Hexadecimals	✓
Octals	✓
Conditionals	✓
Functions	✓
Classes	✓
While Loops	✓
Booleans	✓		true false
Print() Debugging	✓		print_string
MultiLine Comments	✓	(* A comment *)	(* *)
Module Pattern	✓	(* In OCaml, every piece of code is wrapped into a module. ) ( amodule.ml ) let hello () = print_endline "Hello" ( bmodule.ml *) Amodule.hello ()
Multiple Inheritance	✓
Comments	✓	(* This is a single-line comment. ) ( This is a * multi-line * comment. *)
Semantic Indentation	ϴ
Line Comments	ϴ

Trending OCaml repos on GitHub

repo	stars	description
coq	2275	"Coq is a formal proof management system. It provides a formal language to write mathematical definitions executable algorithms and theorems together with an environment for semi-interactive development of machine-checked proofs."
pyre-check	2985	Performant type-checking for python.
ocaml	2473	"The core OCaml system: compilers runtime system base libraries"
flow	19958	Adds static typing to JavaScript to improve developer productivity and code quality.
infer	10169	"A static analyzer for Java C C++ and Objective-C"

Books about OCaml on goodreads

title	author	year	reviews	ratings	rating
Real World OCaml: Functional programming for the masses	Yaron Minsky	2013	7	88	4.28
Unix System Programming in OCaml	Xavier Leroy	1994	0	1	4.00
Apprendre à programmer avec OCaml	Sylvain Conchon	2014	0	1	4.00
Using, Understanding, and Unraveling The OCaml Language: From Practice to Theory and vice versa	Didier Rémy		0	1	5.00
Apprendre à programmer avec OCaml: Algorithmes et structures de données (Noire)	Jean-Christophe Filliatre		0	0	0.0

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