How do I install and use dotnet-repl on Windows?

Install it globally using `dotnet tool install -g dotnet-repl`, then run `dotnet repl`. It works on any platform with .NET SDK installed, and you can set default kernels via environment variables or command-line flags.

Can dotnet-repl run Jupyter notebooks from the command line?

Yes, use `dotnet repl --run notebook.ipynb` to execute .ipynb files, and it supports output formats like .ipynb or .trx for testing in CI pipelines, as detailed in the README's file support section.

How does dotnet-repl compare to the C# Interactive Window in Visual Studio?

dotnet-repl is command-line based and polyglot, supporting multiple languages, while Visual Studio's Interactive Window is GUI-integrated but limited to C#. dotnet-repl offers more flexibility for cross-language work but lacks IDE features like debugging.

Is it possible to save my REPL session state in dotnet-repl?

No, sessions are ephemeral, but you can initialize them from files or use scripts to recreate environments. The README mentions support for running files with --run, but there's no built-in session persistence.

How to add NuGet packages in dotnet-repl?

Use the #r nuget command followed by the package name, e.g., `#r nuget Newtonsoft.Json`, to install and reference packages directly in the session. This is shown in the README's NuGet integration example.

Does dotnet-repl support debugging with breakpoints?

No, it does not support debugging features; it's primarily for code execution and prototyping. For debugging, you'd need a full IDE like Visual Studio or VS Code with appropriate extensions.

Open-Awesome

dotnet-repl

MITC#

A polyglot command-line REPL for .NET supporting C#, F#, PowerShell, and more, built on .NET Interactive.

GitHub

844 stars42 forks0 contributors

What is dotnet-repl?

dotnet-repl is a polyglot REPL (Read-Eval-Print Loop) tool for the .NET ecosystem, built on .NET Interactive. It allows developers to write and execute code in multiple .NET languages—such as C#, F#, and PowerShell—directly from the command line, supporting interactive coding, script running, and rapid prototyping.

Target Audience

.NET developers, data scientists, and educators who need a lightweight, interactive environment for testing code snippets, learning languages, or running scripts without launching a full IDE.

Value Proposition

It offers a unified, polyglot REPL experience on the command line, leveraging .NET Interactive's capabilities for multi-language support, NuGet integration, and magic commands, making it more versatile than single-language REPLs.

Overview

A polyglot REPL built on .NET Interactive

Use Cases

Best For

Quickly testing C# or F# code snippets in a scripting dialect
Interactive learning and experimentation with .NET languages
Running and testing Jupyter notebooks (`.ipynb`) or .NET Interactive scripts (`.dib`) from the terminal
Prototyping with NuGet packages in an isolated REPL session
Automating script execution with parameterized inputs for CI/CD pipelines
Switching between multiple .NET languages in a single coding session

Not Ideal For

Teams requiring integrated debugging and step-through execution in their REPL environment
Projects built on .NET Framework 4.x or other legacy .NET versions not supported by .NET Interactive
Developers who prefer a GUI-based interactive environment with rich visual feedback and tools
Production environments needing a stable, officially supported REPL with guaranteed SLAs and extensive documentation

Pros & Cons

Pros

Polyglot Language Support

Allows seamless switching between C#, F#, PowerShell, and other languages in a single session, leveraging .NET Interactive's capabilities for a unified coding experience.

Direct NuGet Integration

Enables on-the-fly installation and use of NuGet packages with #r nuget commands, facilitating rapid prototyping and library testing without external setup.

Flexible File Execution

Supports running and initializing sessions from various file types like .ipynb, .csx, and .fsx, making it versatile for scripting, testing, and CI/CD integration.

Magic Commands Enhancement

Provides advanced functionalities through magic commands like #!import and #!help, extending beyond basic REPL features to include database connections and script imports.

Cons

Experimental and Unofficial

As a personal project noted in the README, it may have stability issues, slower updates, and less community support compared to official .NET tools like Visual Studio Interactive.

Limited Source Code Support

For C# and F# source files, the README admits that some language constructs such as namespaces are not fully supported, restricting execution of complex codebases.

Terminal-Only Interface

Lacks graphical elements like syntax highlighting or visual debugging, which might hinder users accustomed to IDE-based REPLs with richer feedback and tools.

Frequently Asked Questions

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