PinCase: A Type-Safe and Expressive Way to Handle Errors in Rust

PinCase is a type-safe and expressive way to handle errors in Rust. It allows you to specify the types of errors that can occur in your function, and provides a way to handle those errors in a structured and predictable way.

In Rust, functions can return multiple values at once by using tuples or arrays. However, this can make it difficult to handle errors in a type-safe way, because you need to know how many values are being returned and what types they have. PinCase helps solve this problem by allowing you to specify the types of errors that can occur, and providing a way to handle those errors in a structured and predictable way.

Here's an example of how PinCase is used:
```
fn my_function(x: i32) -> Result<(), &str> {
match x {
// Success case
0 => Ok(()),
// Error case
_ => Err("Invalid input"),
}
}
```
In this example, `my_function` takes an `i32` argument and returns a `Result` of either success (`Ok(())`) or error (`Err("Invalid input")`). The `PinCase` keyword is used to specify the types of errors that can occur.

You can then use PinCase in your code like this:
```
let result = my_function(42);
match result {
Ok(_) => println!("Success"),
Err("Invalid input") => println!("Error"),
}
```
This code will print "Success" if `my_function` returns `Ok(())` and "Error" if it returns `Err("Invalid input")`. The `PinCase` keyword allows you to specify the types of errors that can occur, so you don't need to worry about the specific types of errors that might be returned.