ResultErrortype

ResultErrortype is a generic, sum-type construct used in programming to represent the outcome of an operation that may succeed or fail. It encapsulates either a successful value or an error description, enabling explicit handling of failure without relying on exceptions.

Typically, ResultErrortype is parameterized by two types: the Ok type representing the successful value and the Err type representing the error. In many languages it is implemented as a discriminated union with two variants: Ok(value) and Err(error).

Usage involves returning a ResultErrortype from a function. Callers pattern-match or branch on the variant to perform appropriate actions, propagate errors upward, or convert errors to user-facing messages. This approach makes error paths explicit and can improve reliability and readability.

Design considerations include how to construct errors, what information the Err variant carries (code, message, context), and how to propagate results efficiently. Some implementations distinguish between recoverable and unrecoverable errors or provide helper methods to unwrap, map, or transform results while preserving error information.

Compared with exceptions, ResultErrortype enforces handling at compile time in languages with static typing and algebraic data types. However, it can introduce boilerplate in verbose languages and requires discipline to propagate errors consistently.

See also: Result type, Either type, Option type, error handling.