OptionalorElselike

OptionalorElselike is a programming concept that provides a unified approach to handling optional values by attaching an else-like fallback that is used when the optional is empty. It aims to reduce boilerplate conditional checks and clarify what value should be produced when data is missing.

Mechanism and behavior: The concept centers on an operator or function that takes two inputs: an optional value and a fallback expression or value. If the optional contains a value, that value is returned. If the optional is empty, the fallback is evaluated or returned. Many designs favor lazy evaluation of the fallback to avoid unnecessary computation.

Syntax and usage: In pseudocode, OptionalorElselike can be expressed as:

result = OptionalorElselike(optValue, defaultValue)

or as a method form on the optional:

result = optValue.orElselike(() => computeDefault())

Some languages provide a built-in nil-coalescing or orElse-like construct that achieves a similar result, returning the contained value or applying the fallback.

Relation to existing patterns: OptionalorElselike mirrors established concepts such as Rust’s unwrap_or_else, Kotlin’s defaulting with elvis-like behavior, Swift’s nil-coalescing operator, and Java’s Optional.orElseGet. It is a language-agnostic pattern rather than a specific syntax, designed to streamline code that must handle optional data.

Considerations and variants: Implementations vary in whether the fallback is evaluated eagerly or lazily, and whether the operator is a language construct or a library function. Potential downsides include readability concerns for unfamiliar readers and the need to choose consistent naming across a codebase. See also Optional, Maybe, Nil-coalescing operator, Unwrap.

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