Option

The Option component represents a value that may or may not be present. It replaces nullable types (?T) with explicit Some/None semantics, making the absence of a value intentional and impossible to ignore.

Instead of returning null and hoping callers remember to check, you return an Option that forces the caller to handle both cases.

Design

Option<T> is a single readonly class with two states:

• Option::some($value) -- A value is present
• Option::none() -- No value is present

Convenience functions some(), none(), and from_nullable() are available in the Psl\Option namespace.

Usage

Creating Options

@example('types/option-creating.php')

Checking and Unwrapping

@example('types/option-checking.php')

Transforming Values

@example('types/option-transforming.php')

Pattern Matching with proceed()

Handle both cases and return a unified result:

@example('types/option-proceed.php')

Side Effects with apply()

Run a closure on the value without changing the Option:

@example('types/option-apply.php')

Filtering

@example('types/option-filtering.php')

Combining Options

@example('types/option-combining.php')

When to Use Option

• Repository lookups: find_by_id() returns Option<Entity> instead of ?Entity
• Configuration: get_setting() returns Option<string> -- absence is explicit
• Chained lookups: Use andThen() to chain fallible lookups without nested null checks
• Safe data access: Parse user input with from_nullable() and transform with map()

See src/Psl/Option/ for the full API.