type Validator interface {
    Validate(input string) error
}

type PasswordValidator struct {
    MinLength int
}

func (v *PasswordValidator) Validate(input string) error {
    if len(input) < v.MinLength {
        return fmt.Errorf("password must be at least %d characters", v.MinLength)
    }
    return nil
}

// Usage
validator := &PasswordValidator{MinLength: 10}
input := ziva.NewInputTask("Password", "Enter password:").
    WithValidator(validator)

type ChainValidator struct {
    validators []Validator
}

func (c *ChainValidator) Validate(input string) error {
    for _, v := range c.validators {
        if err := v.Validate(input); err != nil {
            return err
        }
    }
    return nil
}

type ConditionalValidator struct {
    condition func(string) bool
    validator Validator
}

func (c *ConditionalValidator) Validate(input string) error {
    if c.condition(input) {
        return c.validator.Validate(input)
    }
    return nil
}