prototype

Combines two maybes such that if they both have values (are a Just) their values are concatenated. Maybe values are expected to be Fantasy Land 1.x semigroups and implement a concat method.

Performs a deep-comparison of two Maybe values for equality. See adt/union/derivations/equality for details.

Tests if an arbitrary value is a Maybe instance.

Constructs a Maybe containing no value (a Nothing).

Constructs a Maybe value that represents a successful value (a Just).

A convenience method for the folktale/conversions/maybe-to-result module.

A convenience method for the folktale/conversions/maybe-to-validation module.

A textual representation for Maybe instances.

A textual representation for Maybe instances.

Extracts the value of a Maybe structure, if it exists (i.e.: is a Just), otherwise returns the provided default value.

Extracts the value from a Just structure.

Part of the Applicative instance for Fantasy Land 1.x. See the apply method for details.

Part of the Applicative instance for Fantasy Land 2.x+. See the apply method for details.

Part of the Monad instance for Fantasy Land 2.x+. See the chain method for details.

Part of the Semigroup instance for Fantasy Land 2.x+. See the concat method for details.

Part of the Monoid instance for Fantasy Land 2.x+. See the empty method for details.

Part of the Setoid instance for Fantasy Land 2.x+. See the equals method for details.

Part of the Functor instance for Fantasy Land 2.x+. See the map method for details.

Part of the Applicative instance for Fantasy Land 2.x+. See the of method for details.

Allows a function to provide functionality to variants in an union.

Applies a function to each variant of the Maybe structure.

Chooses and executes a function for each variant in the Maybe structure.

Allows recovering from from failed Maybe values.

Parses a JavaScript object previously serialised as aMaybe.toJSON() into a proper Maybe structure.

Converts a Maybe value to a JavaScript object that may be stored as a JSON value.

The constructor function for this variant.

The variants in the Maybe structure.

Transforms a Maybe value using a function contained in another Maybe. As with .map(), the Maybe values are expected to be Just, and no operation is performed if any of them is a Nothing.

Transforms an entire Maybe structure with the provided function. As with .map(), the transformation is only applied if the value is a Just, but unlike .map() the transformation is expected to return a new Maybe value.

If the Maybe is a Just, passes its value to the predicate. If the predicate returns true, then the Maybe is returned unchanged. In every other case, a Nothing gets returned.

Transforms the value inside a Maybe structure with an unary function. Only transforms values that are successful (Just), and constructs a new Maybe as a result.

Constructs a Maybe value that represents a successful value (a Just).

Constructs a Maybe value that represents a failure (a Nothing).