orOptionalValue

orOptionalValue is a conceptual pattern used in programming with optional values. It refers to selecting a value from two sources where a primary optional is preferred if it contains a value, and a secondary optional serves as a fallback when the primary is nil. The construct can be implemented as a function, operator, or combinator, depending on the language.

Semantics and variants: In its most common form, orOptionalValue takes two optionals of the same type and yields the first non-nil result. If the primary optional is non-nil, its value is used; otherwise, the secondary optional is examined. Depending on the language, the result may be another optional (nil if both are nil) or a non-optional value obtained by unwrapping with a default. Some variants allow chaining multiple optional sources, effectively creating a prioritized fallback sequence.

Relation to related concepts: orOptionalValue is related to patterns such as nil-coalescing, orElse, and the Maybe/Optional monads found in various languages. In languages with a built-in nil-coalescing operator, a similar outcome is achieved by combining the primary optional with a fallback through a concise syntax. The concept emphasizes explicit handling of missing values and reduces repetitive nil-checks in code.

Typical use cases: The pattern is useful when data can come from multiple sources, such as a user-provided value, a cached value, or a default. It helps ensure that an operation proceeds with a valid value when possible, while preserving a defined fallback when necessary.

See also: Optional, Maybe, nil-coalescing operator, fallback, orElse.