Validates that at least one of several alternative validators succeeds.

Any provides disjunctive validation semantics. Unlike the default validation pipeline, which is conjunctive (all validators must succeed), Any succeeds as soon as a single validator passes. If all validators fail, validation fails with a single aggregated ValidationError.

This validator is useful for expressing alternatives such as: "value must satisfy rule A or rule B".

Options

• :validators (required) A non-empty list of validators. Each entry may be:

  • a validator module implementing Funx.Validate.Behaviour
  • a {Validator, opts} tuple for optioned validators
  • a validator function with arity 1, 2, or 3 (e.g., result of validate do...end)
  • a {validator_function, opts} tuple for optioned function validators

• :message (optional) A zero-arity callback (() -> String.t()) used to override the default error message when all alternatives fail.

Semantics

• Validators are evaluated left-to-right.
• Evaluation short-circuits on the first successful validation.
• If any validator returns Right, the value is returned unchanged.
• If all validators return Left, a single ValidationError is returned.
• Nothing values succeed if any validator accepts them.
• Just values are unwrapped before validation.

Examples

iex> Funx.Validator.Any.validate(10,
...>   validators: [Funx.Validator.Positive, Funx.Validator.Negative]
...> )
%Funx.Monad.Either.Right{right: 10}

iex> Funx.Validator.Any.validate(0,
...>   validators: [Funx.Validator.Positive, Funx.Validator.Negative]
...> )
%Funx.Monad.Either.Left{
  left: %Funx.Errors.ValidationError{
    errors: ["value must satisfy at least one alternative"]
  }
}

iex> Funx.Validator.Any.validate(0,
...>   validators: [Funx.Validator.Positive, Funx.Validator.Negative],
...>   message: fn -> "must be positive or negative" end
...> )
%Funx.Monad.Either.Left{
  left: %Funx.Errors.ValidationError{
    errors: ["must be positive or negative"]
  }
}