chain

Transforms the value and context of a Validation computation with an unary function. As with .map(), the transformation is only applied if the value is a Success, but the transformation is expected a new Validation value, which then becomes the result of the function.

Signature

chain(validation, fn)

Type(what is this?)

forall a, b, c: (Validation a b, (b) => Validation a c) => Validation a c

Documentation

Example:

const { Success, Failure, chain } = require('folktale/validation');

chain(Success('a'), x => Success(x.toUpperCase()));
// ==> Success('A')

chain(Success('a'), x => Failure(x));
// ==> Failure('a')

chain(Failure('a'), x => Success(x.toUpperCase()));
// ==> Failure('a')

Properties

Source Code

Defined in source/validation/chain.js at line 17, column 0

(validation, fn) =>
  validation.matchWith({
    Success: ({ value }) => fn(value),
    Failure: ({ value }) => Failure(value)
  })