# rustyrepl
The easy Rust Read-Evaluate-Print-Loop (REPL) utility crate
[
](https://github.com/slawlor/repl)
[
](https://crates.io/crates/rustyrepl)
[
](https://docs.rs/rustyrepl)
[](https://github.com/slawlor/repl/actions/workflows/ci.yaml)
## About
`rustyrepl` is a simple crate to facilitate creation of Read, Evaluate, Print, Loop utilities at the command-line. A unique combination of `rustyline` and `clap` to build a simple REPL interface
with handy argument parsing.
## Purpose
1. Capturing exits/quits of the REPL interface
2. Storing and managing REPL history commands as well as an index of said commands for you
3. Allowing operators to get a help menu at any point, using the full Clap supported help interface (i.e. sub-command help as well)
4. Processing the commands as incoming
# Usage
First, add rustyrepl to your `Cargo.toml` file
```toml
[dependencies]
rustyrepl = "0.2"
```
Next:
```rust
use anyhow::Result;
use clap::{Parser, Subcommand};
use rustyrepl::{Repl, ReplCommandProcessor};
/// The enum of sub-commands supported by the CLI
#[derive(Subcommand, Clone, Debug)]
pub enum Command {
/// Execute a test command
Test,
}
/// The general CLI, essentially a wrapper for the sub-commands [Commands]
#[derive(Parser, Clone, Debug)]
pub struct Cli {
#[clap(subcommand)]
command: Command,
}
#[derive(Debug)]
pub struct CliProcessor {}
#[async_trait::async_trait]
impl ReplCommandProcessor for CliProcessor {
fn is_quit(&self, command: &str) -> bool {
matches!(command, "quit" | "exit")
}
async fn process_command(&self, command: Cli) -> Result<()> {
match command.command {
Command::Test => println!("A wild test appeared!"),
}
Ok(())
}
}
// MAIN //
#[tokio::main]
async fn main() -> Result<()> {
let processor: Box> = Box::new(CliProcessor {});
let mut repl = Repl::::new(processor, None, Some(">>".to_string()))?;
repl.process().await
}
```
This small program will startup up a REPL with the prompt ">>" which you can interact with
```text
>> help
The general CLI, essentially a wrapper for the sub-commands [Commands]
Usage: repl-interface
Commands:
test Execute a test command
help Print this message or the help of the given subcommand(s)
Options:
-h, --help Print help
```