either.md

Either

Either is a monad and can be used as a generic structure for a type with two possibilities: a Left a or a Right b. It represents the logical disjunction between a and b.

A common use of this structure is to handle error cases and situations where a computation might fail, while also providing additional information about the failure. It is used to represent a value that is either correct or an error. By convention, the Left constructor is used to hold an error value, and the Right constructor is used to hold a correct value. This structure forces explicit handling of failures and avoids the problems associated with throwing exceptions.

Implements: BiFunctor, Monad, Setoid

• Either
  • Either.of(v)
  • Either.Right(v)
  • Either.Left(v)
  • Either.fromNullable(v)
  • Either.withDefault(def, v)
  • Either.swap()
  • Either.try(f)
  • Either.bimap(e, fl, fr)
  • Either.isLeft(e)
  • Either.isRight(e)
  • Either.equals(n)
  • Either.map(f)
  • Either.bimap(fl, fr)
  • Either.chain(f)
  • Either.swap()
  • Either.isLeft()
  • Either.isRight()
  • Either.ap(j)
  • Either.getValue()

Either.of(v)

Creates a Right Either.

Param	Type	Description
v	any	Value

Either.Right(v)

Creates a Right Either.

Param	Type	Description
v	any	Value

Either.Left(v)

Creates a Left Either.

Param	Type	Description
v	any	Value

Either.fromNullable(v)

Creates a Right if the value is not null or undefined; otherwise, creates a Left.

Param	Type	Description
v	any	Value

Either.withDefault(def, v)

Creates a Right if the value v is not null or undefined; otherwise, creates a Right with the default value def.

Param	Type	Description
def	any	Default value
v	any	Value

Either.swap()

Swaps the Left and Right elements of the current Either.

Either.try(f)

Executes the passed function that may throw and converts it to an Either type.

Param	Type	Description
f	function	A function that may throw an error

Either.bimap(e, fl, fr)

A static method that applies fl to the Left element or fr to the Right element of the current Either.

Param	Type	Description
e	any	Either type
fl	function	Function to be applied on the Left element
fr	function	Function to be applied on the Right element

Either.isLeft(e)

A static method that returns true if the passed Either is a Left.

Param	Type	Description
e	any	Either type

Either.isRight(e)

A static method that returns true if the passed Either is a Right.

Param	Type	Description
e	any	Either type

Either.equals(n)

Returns true if the current and the passed element are of Either type with the same value.

Param	Type	Description
n	any	Any value of type Setoid

Either.map(f)

Applies the passed function to the value of the current Either if it is a Right.

Param	Type	Description
f	function	Function

Either.bimap(fl, fr)

Applies fl to the Left element or fr to the Right element of the current Either.

Param	Type	Description
fl	function	Function to be applied on the Left element
fr	function	Function to be applied on the Right element

Either.chain(f)

An instance method that can chain together many computations that return an Either type.

Param	Type	Description
f	function	Function that returns another Either

Either.swap()

Swaps the Left and Right elements of the current Either.

Either.isLeft()

An instance method that returns true if the current Either is a Left.

Either.isRight()

An instance method that returns true if the current Either is a Right.

Either.ap(j)

Applies the function inside the passed Either to the current Either if it is a Right.

Param	Type	Description
j	any	Either with a function

Either.getValue()

Gets the value inside the Either.