addPrefix method

void addPrefix(
  1. IValidator prefix(
    1. IValidator child
    )
)

Adds a prefix value-mapping validator that runs before coercion and post-validators. Used for operations like pluckValue that extract values from containers.

Implementation

void addPrefix(IValidator Function(IValidator child) prefix) {
  if (_prefix == null) {
    _prefix = prefix;
  } else {
    final existing = _prefix!;
    _prefix = (child) => existing(prefix(child));
  }
}