run is a versatile polyglot command runner and smart REPL (Read-Eval-Print Loop) developed in Rust, designed for developers who work across multiple programming languages. It provides a seamless command line interface that allows users to script, compile, and iterate in more than 25 programming languages without the need for multiple tools.

Key Features

• Multi-language Support: Execute code snippets or files in languages like Python, Ruby, JavaScript, Go, C++, and many more with a single command.
• Persistent REPL: Engage with an interactive REPL that retains session state, allowing for a fluid coding experience.
• Simplified Syntax: With commands such as run --lang python --code "print('hello, polyglot world!')", quickly run code without switching between different command line interfaces.

Quick Start

Begin using run easily with commands like:

# Display build metadata
run --version

# Execute a code snippet
run --lang python --code "print('hello, polyglot world!')"

# Detect language from file extension
run examples/go/hello/main.go

# Enter the REPL environment
run

# Pipe JSON input into Node.js
echo '{"name":"Ada"}' | run js --code "const data = JSON.parse(require('fs').readFileSync(0, 'utf8')); console.log(`hi ${data.name}`)"

How It Works

run leverages existing toolchains, enabling each LanguageEngine to:

1. Verify availability of the required interpreter or compiler.
2. Set up a workspace for executing scripts or compiling code.
3. Execute code snippets or read from standard input and output results uniformly.
4. Manage REPL session states effectively.

This architecture maintains a lightweight core while facilitating easy integration for new languages or toolchains.

Supported Languages

The command runner supports a variety of languages categorized as follows:

• Scripting: Bash, Python, Ruby, PHP, Perl, Lua, R, Elixir
• Web & Typed Scripting: JavaScript, TypeScript, Dart, Swift, Kotlin
• Systems & Compiled: C, C++, Rust, Go, Zig, Nim, Haskell, Crystal, C#, Java, Julia

Example Usage

Explore practical examples included in the repository:

run examples/rust/hello.rs
run examples/typescript/progress.ts
run examples/python/counter.py

Interactive REPL Commands

Within the REPL, users can leverage commands to optimize their workflow:

run streamlines the development process for polyglot developers, enabling effective script execution and management across numerous languages.