# Kust
_**Write Rust like you never left Kotlin.**_
Kust aims to make new Rustaceans, familiar with Kotlin, feel right at home. It's also aimed to bring a few of Kotlin's goodies to the existing Rust community, without compromising on any of Rust's benefits.
## Scope functions
Perform side effects and modify objects in a more concise and readable way.
Available functions:
- `using` - use a value in an expression without creating a new variable (returns a new value)
- `also` - perform a side effect using a value without modifying it (returns the same value)
- `apply` - modify a value before returning it (returns the same value)
> [!NOTE]
> The Kotlin `let` function has been renamed to `using`, as the `let` keyword is reserved in Rust.
> See [Kotlin documentation](https://kotlinlang.org/docs/scope-functions.html).
### Examples
**Using**
```rust
use some::Person;
use kust::ScopeFunctions;
fn greet_person(encoded_person: &str) -> String {
let name = Person::from_str(encoded_person).using(|person| format!("{} {}", person.first_name, person.last_name));
println!("Hi, {name}!")
}
```
**Also**
```rust
use some::ComplexType;
use kust::ScopeFunctions;
fn parse_items(&items: Vec<&str>) -> Vec<ComplexType> {
items
// easily add a debug print for each item
.map(|item| ComplexType::from_str(item).also(|it| println!("{it}")))
.filter(|item| !item.is_empty())
.collect()
}
```
**Apply**
```rust
use some::Person;
use kust::ScopeFunctions;
fn get_users() -> Vec<Person> {
vec![
// set an additional attribute
Person::create("Mike").apply(|it| it.age = 34),
Person::create("Linda").apply(|it| it.age = 25),
]
}
```