Again, if you install OCaml natively in Windows, you can run: .\hello.exe

Linux uses forward slash to separate directory and Windows uses backslash

If you install OCaml natively in Windows (not using WSL), I think you can directly run: ocamlc -o hello.exe hello.ml

Previous instructions in installing: https://hyp.is/4XRZ3EKyEfCr8--I_WXR9w/cs3110.github.io/textbook/chapters/preface/install.html

This statement may be a bit misleading. Alan has never recommend ML language in his life, instead he indeed recommends to use LiSP language.

I dig through the documentation and have written this guide for Windows user that don't want to use WSL

Installing OCaml Natively on Windows Using PowerShell

This guide explains how to set up a native OCaml development environment on Windows using PowerShell. You will install the latest PowerShell (pwsh), Git, and opam (the OCaml package manager) along with some essential OCaml-related tools. Finally, you will configure your PowerShell profile so OCaml is available every time you launch a new session.

1. Install PowerShell

PowerShell 7 is recommended since it comes with new features and improvements compared to Windows PowerShell 5.1. Note that PowerShell 7 installs as pwsh.exe (instead of the legacy powershell.exe).

• Download and Install via MSI Package:<br /> Visit the Installing PowerShell on Windows (MSI Package) page on Microsoft Learn.<br /> Download the MSI package and follow the installation prompts. Once installed, launch PowerShell 7 by running pwsh.exe.

2. Install Git

Git is required as a dependency for many OCaml tools. Download the latest x64 setup for Windows:

• Download Git for Windows:<br /> Go to the Git Downloads for Windows page and click the link to download the latest x64 version.

3. Install opam

opam is the OCaml package manager and is the recommended way to manage OCaml installations on Windows.

Step 1: Install opam Using WinGet

Open PowerShell 7 (pwsh.exe) and execute the following command:

powershell winget install OCaml.opam

Step 2: Initialize opam

Once the installation completes, initialize opam with:

powershell opam init

During initialization, you will be asked two questions:

• First Prompt: Select the recommended setting.
• Second Prompt: When asked if you want to switch to another shell, choose No.

Please note that the initialization process may take a while depending on your computer's performance.

4. Install Essential Platform Tools

After setting up opam, install additional OCaml tools that will improve your development experience. Run the following command in PowerShell:

powershell opam install ocaml-lsp-server odoc ocamlformat utop

Like before, the installation time may vary based on your system.

5. Configure Your PowerShell Profile for OCaml

To access your OCaml environment in every PowerShell session, you need to update your PowerShell profile.

Temporary Session Command

For the current session, you can load the opam environment by running:

powershell (& opam env) -split '\r?\n' | ForEach-Object { Invoke-Expression $_ }

This command sets up the OCaml-related environment variables for the active session only.

Making the Configuration Persistent

1. Locate Your PowerShell Profile File:<br /> Execute the following command to reveal the profile path:

   powershell $profile

   You might receive a path similar to:

   C:\Users\<username>\Documents\PowerShell\Microsoft.PowerShell_profile.ps1

2. Edit (or Create) Your Profile File:

   • Open the file at the path above.

   • If the file does not exist, create a new file with the same name (Microsoft.PowerShell_profile.ps1).

   • Add the following line to the file:

     powershell (& opam env) -split '\r?\n' | ForEach-Object { Invoke-Expression $_ }

   • Save the file.

Now, every time you launch PowerShell, the OCaml environment will be automatically configured.

6. Verify Your Installation

To verify that everything is set up correctly:

1. Open a new PowerShell session.

2. Launch the OCaml Read-Evaluate-Print Loop (REPL) by typing:

   powershell utop

3. In the utop prompt, test with a simple expression:

   ocaml 21 + 43;;

   The REPL should evaluate the expression and return the corresponding result.

References

• OCaml on Windows Documentation
• Installing PowerShell on Windows
• Git for Windows Downloads