🦀 rusty_repl

A lightweight, modular framework for building interactive REPLs in Rust — with clean prompts, terminal isolation, and customisable input handling.

✨ Features

🖥️ Alternate screen mode — clean, isolated terminal workspace
💬 Custom prompts — easily define your own Prompt style via CleanPrompt
⚡ Input handling loop — powered by reedline
🧹 Automatic cleanup — restores cursor, title, and screen on exit
🎨 Keyword highlighting — built-in highlighter with custom color schemes (KeywordStyle)
🧩 Extensible design — drop in new highlighters, prompts, or REPL logic
🛠️ Config builder — safely construct REPL configuration with ReplConfig::new().with_title(...).with_prompt(...).with_kw_style(...)

🚀 Quick Start

Add to your Cargo.toml:

[dependencies]
rusty_repl = "0.3.0"

Then in your project:

use rusty_repl::Repl;

fn input_handler(cmd: String) -> bool {
    match cmd.as_str() {
        "e" | "q" | "quit" | "exit" => {
            return true;
        }
        val => println!("{val}"),
    };

    false
}

fn main() {
    // Use default configuration
    let repl_manager = Repl::new();

    // Run REPL loop
    let _ = repl_manager.run(run);
}

use rusty_repl::{CleanPrompt, Color, DefaultPromptSegment, KeywordStyle, Repl, ReplConfig};

fn input_handler(cmd: String) -> bool {
    match cmd.as_str() {
        "e" | "q" | "quit" | "exit" => {
            return true;
        }
        val => println!("{val}"),
    };

    false
}

fn main() {
    // Configure keywords
    let ks = KeywordStyle::new(
        vec!["ls", "pwd", "cd", "e", "q", "quit", "exit"],
        Color::Red,
    );

    // Configure prompt
    let default_prompt = CleanPrompt::from(
        DefaultPromptSegment::Basic("❯❯❯ ".to_string()),
        DefaultPromptSegment::Empty,
    );

    // Build REPL configuration
    let cfg = ReplConfig::new("REPL")
        .with_kw_style(ks)
        .with_prompt(default_prompt);

    let repl_manager = Repl::from(cfg);

    // Run REPL loop
    let _ = repl_manager.run(run);
}

This opens an alternate terminal screen with a minimal prompt.

Type exit to leave the session.

🧩 Architecture

Module	Responsibility
`repl::input`	Handles user input with `reedline`
`repl::terminal`	Manages terminal (alternate screen, cursor, cleanup)
`repl::prompt`	Defines a cleaner, customisable prompt
`repl::highlighter`	Highlights configured keywords during input
`repl::style`	Configures keyword styles (colors, word list)
`repl::repl`	Connects all components into a cohesive REPL session

🔧 Future Enhancements

💾 Persistent command history
🧠 Syntax-aware input completion
🌈 Theming and multi-color highlighting

📜 License

Licensed under the MIT License

📝 Changelog

0.3.0

Introduced ReplConfig builder with .with_title(), .with_prompt(), .with_kw_style()
REPL prompt now uses Arc<dyn Prompt> to avoid ownership/move issues
InputHandler stores the prompt internally; run no longer requires external prompt
Updated all modules to consume Arc<ReplConfig> instead of cloning individual fields
Documentation updated for builder pattern, prompt handling, and Arc usage
Example code updated to reflect new API

0.2.0

Added keyword highlighting support
Introduced KeywordHighlighter for basic keyword-based styling.
Exposed KeywordStyle as part of the public API.
Updated Repl::new to accept an optional KeywordStyle argument.

rusty_repl 0.3.0