Function: mapOrElse()
Call Signature
mapOrElse<
T,U>(orElseFn,mapFn,maybe):U
Map over a Maybe instance and get out the value if maybe is a Just, or use a function to construct a default value if maybe is Nothing.
const length = (s: string) => s.length;
const getDefault = () => 0;
const justAString = Maybe.just('string');
const theStringLength = mapOrElse(getDefault, length, justAString);
console.log(theStringLength); // 6
const notAString = Maybe.nothing<string>();
const notAStringLength = mapOrElse(getDefault, length, notAString)
console.log(notAStringLength); // 0Type Parameters
T
T extends object
The type of the wrapped value.
U
U extends object
The type of the wrapped value of the returned Maybe.
Parameters
orElseFn
() => U
The function to apply if maybe is Nothing.
mapFn
(t) => U
The function to apply to the wrapped value if maybe is Just
maybe
Maybe<T>
The Maybe instance to map over.
Returns
U
Call Signature
mapOrElse<
T,U>(orElseFn,mapFn): (maybe) =>U
Map over a Maybe instance and get out the value if maybe is a Just, or use a function to construct a default value if maybe is Nothing.
const length = (s: string) => s.length;
const getDefault = () => 0;
const justAString = Maybe.just('string');
const theStringLength = mapOrElse(getDefault, length, justAString);
console.log(theStringLength); // 6
const notAString = Maybe.nothing<string>();
const notAStringLength = mapOrElse(getDefault, length, notAString)
console.log(notAStringLength); // 0Type Parameters
T
T extends object
The type of the wrapped value.
U
U extends object
The type of the wrapped value of the returned Maybe.
Parameters
orElseFn
() => U
The function to apply if maybe is Nothing.
mapFn
(t) => U
The function to apply to the wrapped value if maybe is Just
Returns
(maybe) => U
Call Signature
mapOrElse<
T,U>(orElseFn): (mapFn) => (maybe) =>U
Map over a Maybe instance and get out the value if maybe is a Just, or use a function to construct a default value if maybe is Nothing.
const length = (s: string) => s.length;
const getDefault = () => 0;
const justAString = Maybe.just('string');
const theStringLength = mapOrElse(getDefault, length, justAString);
console.log(theStringLength); // 6
const notAString = Maybe.nothing<string>();
const notAStringLength = mapOrElse(getDefault, length, notAString)
console.log(notAStringLength); // 0Type Parameters
T
T extends object
The type of the wrapped value.
U
U extends object
The type of the wrapped value of the returned Maybe.
Parameters
orElseFn
() => U
The function to apply if maybe is Nothing.
Returns
(mapFn) => (maybe) => U