Type Alias: Validation<T, E>

Validation<T, E> = Valid<T> | Invalid<E>

Defined in: validation/types.ts:39

Validation type representing either success (Valid) or failure (Invalid).

Validation is similar to Result but optimized for error accumulation. While Result short-circuits on the first error (fail-fast), Validation accumulates all errors (fail-slow), making it ideal for form validation and multi-field data validation.

Type Parameters

T

T

The type of the success value

E

E

The type of error values (stored as array)

Example

type FormValidation = Validation<User, string>

const success: FormValidation = { _tag: 'Valid', value: { name: 'John', email: 'john@example.com' } }
const failure: FormValidation = { _tag: 'Invalid', errors: ['Name too short', 'Invalid email'] }