Result Type in Hoshi-lang

The Result<T, E> type is a standard library feature in Hoshi-lang for functions that can return either a value or an error.

<tt>Result<T, E></tt> Struct

The Result<T, E> struct is an enumeration with two variants:

• Ok(T): Represents success and contains a value of type T.
• Err(E): Represents an error and contains a value of type E.

Methods

• is_ok() : bool: Returns true if the result is Ok.
• is_err() : bool: Returns true if the result is Err.
• unwrap() : T: Returns the value inside an Ok. Panics if the result is Err.
• unwrap_err() : E: Returns the error inside an Err. Panics if the result is Ok.

Static Methods

• ok(value: T) : Result<T, E>: Creates an Ok result.
• err(error: E) : Result<T, E>: Creates an Err result.

Example

use lang "builtin"
use str "str"
 
func test(value: int) : lang.Result<int, str.Str> {
    if (value == 0xe1751aff) {
        return lang.Result<int, str.Str>.ok(value)
    } else {
        return lang.Result<int, str.Str>.err(str.Str("Error: invalid value"))
    }
}
 
func main() : int {
    let result = test(0xe1751aff)
    if (result.is_ok()) {
        let x = result.unwrap()
    } else {
        let err = result.unwrap_err()
    }
    return 0
}