Install OCaml Compiler

OCaml compiler

The recommended way to install the OCaml compiler on a local machine is to use the package manager OPAM.

First, let’s use the following script to install OPAM:

$ sh <(curl -sL https://raw.githubusercontent.com/ocaml/opam/master/shell/install.sh)

The script checks the architecture of the computer and downloads and installs the suitable pre-compiled binary to /usr/local/bin by default.

Verify that OPAM has been installed successfully by typing in the terminal:

$ which opam
/usr/local/bin/opam

Next, follow the [instruction for installing OCaml via OPAM](https://ocaml.org/docs/install.html to install the latest OCaml compiler version. At the time of this writing, the latest OCaml compiler version is 4.12.0.

$ opam init
$ eval `opam env`
$ opam switch create 4.12.0
$ eval `opam env`

After this, install the following tools:

• ocamlc: The OCaml bytecode compiler that compiles OCaml source files to bytecode files.
• ocamlopt: The OCaml native compiler that compiles OCaml source files to native code object files and links them to produce standalone executables.
• ocamlrun: The bytecode interpreter that executes bytecode files produced by ocamlc.

Note: Verify that the OCaml bytecode compiler has been installed successfully before continuing.

$ which ocamlc
/Users/quang/.opam/4.12.0/bin/ocamlc

REPL utop

A great way to learn functional programming with OCaml on a local machine is using the read–eval–print loop (REPL) utop. Use the package manager OPAM mentioned previously to install utop.

$ opam install utop

You can start utop by entering it in the shell.

$ utop

You should see something like the following screenshot: