# Vow
`Serde <--> File` made easy.
Vow is a simple but generic data binding library for Rust. It allows you to bind any type that implements `Serialize + DeserializeOwned` to a file, and keeps the file up-to-date while supporting multiple backends (both synchronous and asynchronous).
Currently [`tokio`](https://tokio.rs) and [`compio`](https://github.com/compio-rs/compio) are supported as asynchronous backends, and [`std::fs`](https://doc.rust-lang.org/std/fs/index.html) is supported as a synchronous backend.
## Example
```rust
use serde::{Deserialize, Serialize};
use vow::*;
#[derive(Serialize, Deserialize)]
struct MyData {
a: i32,
b: String,
}
#[compio::main]
async fn main() {
let mut data = VowAsync::open_compio("/tmp/data.json")
.default(MyData {
a: 42,
b: "hello".to_string(),
})
.overwrite_local()
.build()
.await
.unwrap();
assert_eq!(data.a, 42);
data.update(|data| data.a += 1).await.unwrap();
assert_eq!(data.a, 43);
data.update(|data| data.b += " world!").await.unwrap();
assert_eq!(data.b, "hello world!");
data.map(|data| MyData {
b: String::new(),
..data
})
.await
.unwrap();
assert_eq!(data.b, "");
}
```
For more examples, see the `examples` directory.