Deviceeither

Deviceeither is a theoretical data type used in software design to model computations that interact with hardware devices. It mirrors the standard Either type in functional programming but places emphasis on device context and failure modes that are common in device I/O. As a result, deviceeither helps separate successful results from device-related errors and supports explicit error handling in device drivers and embedded systems.

Definition and variants: at its core, deviceeither is a two-branch sum type with two constructors: Ok(value) representing a successful result, and Err(error) carrying information about the failure. The Err variant commonly includes fields such as deviceId, errorCode, and a human-readable message. The type may also embed minimal device state to aid recovery or retry logic.

Operations and composition: deviceeither supports functional-style composition, including mapping and flat-mapping (bind) operations that propagate errors automatically. Example: connect(device) returns deviceeither; if successful, subsequent operations can be chained; otherwise, error handling is invoked. This approach mirrors the monadic pattern used with Either or Result types but is specialized for device I/O.

Relationship to related concepts: deviceeither is conceptually similar to the Haskell Either and Rust Result types, but with a domain focus on hardware interfaces. In practical implementations, it may be integrated with an IO or hardware abstraction layer and can be combined with retry policies, timeouts, and concurrency primitives.

Applications: used in device drivers, sensor data acquisition, and embedded systems where operations can fail due to connectivity, permissions, or hardware faults. By making errors explicit, deviceeither aids maintainability and robust error handling across complex hardware stacks.

See also: Either, Result, IO, monad, device driver, embedded systems.