# repl-block
[](https://crates.io/crates/repl-block)
[](https://docs.rs/repl-block/latest)



## Synopsis
This crate provides a simple and easy way to build a `Read-Eval-Print-Loop`,
a.k.a. REPL.
## Usage
Add a dependency on this crate to your project's `Cargo.toml`:
``` toml
[dependencies]
repl-block= "0.7.3"
```
Then one can use the `ReplBuilder` type to build an start a REPL like this:
```rust
use repl_block::prelude::{ReplBuilder, ReplBlockResult, Utf8PathBuf};
fn main() -> ReplBlockResult<()> {
let mut evaluator = /* initialize your evaluator */;
let path = Utf8PathBuf::try_from(env::current_dir()?)?.join(".repl.history");
ReplBuilder::default()
// Explicitly register .repl.history as the history file:
.history_filepath(path)
// Register the evaluator; the default evaluator fn is NOP
.evaluator(|query: &str| {
match evaluator.evaluate(query) {
Ok(value) => println!("{value}"),
Err(err) => println!("{err}"),
}
Ok(())
})
.build()? // Use `self` to build a REPL
.start()?;
Ok(())
}
```