Classes

Left

module:either.Left

Right

module:either.Right

Methods

static either(leftCallback, rightCallback, _either_) → {*}

either/Either.js, line 122

Calls matching callback on incoming Either's type; If is a Left (after mapping identity func on it) then calls left-callback and unwraps result else calls right-callback and does the same. Think of it like a functional ternary statement (lol).

Parameters:

Name	Type	Description
leftCallback	function	Mapped over value of monad's identity.
rightCallback	function	"".
_either_	Either | *

Returns:

* -

• Value of unwrapped resulting value of flatMapped, passed-in callback's on passed in monad.

Example

expect(
         either(() => 404, () => 200, compose(right, right, right, right)(true))
       ).toEqual(undefined);

static isLeft(x) → {boolean}

either/Either.js, line 90

Checks for instance of Left constructor.

Parameters:

Name	Type	Description
x	*

Returns:

boolean

static isRight(x) → {boolean}

either/Either.js, line 82

Checks for instance of Right constructor.

Parameters:

Name	Type	Description
x	*

Returns:

boolean

static left(x) → {Left}

either/Either.js, line 66

Returns a new Left

Parameters:

Name	Type	Description
x	*

Returns:

Left

static right(x) → {Right}

either/Either.js, line 74

Returns a Right.

Parameters:

Name	Type	Description
x	*

Returns:

Right

static toEither(x) → {Left|Right}

either/Either.js, line 114

Converts given to an either (Right|Left)

Parameters:

Name	Type	Description
x	*

Returns:

Left | Right

static toLeft(x) → {Left}

either/Either.js, line 106

Returns a Left - if not a Left creates one from given, else returns given.

Parameters:

Name	Type	Description
x	*

Returns:

Left

static toRight(x) → {Right}

either/Either.js, line 98

Returns a Right - if not a Right creates one from given, else returns given.

Parameters:

Name	Type	Description
x	*

Returns:

Right