whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>(
  1. TResult? $default(
    1. Map<String, VersionConstraint?>? environment,
    2. Version? version,
    3. String? publishTo,
    4. Uri? homepage,
    5. Uri? repository,
    6. Uri? issueTracker,
    7. List<String>? topics,
    8. String? documentation,
    9. List<String>? funding,
    10. Map<String, Object?>? platforms,
    11. String? resolution,
    12. Map<String, Dependency>? dependencies,
    )?
)

A variant of when that fallback to returning null

It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case _:
    return null;
}

Implementation

@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( Map<String, VersionConstraint?>? environment,  Version? version,  String? publishTo,  Uri? homepage,  Uri? repository,  Uri? issueTracker,  List<String>? topics,  String? documentation,  List<String>? funding,  Map<String, Object?>? platforms,  String? resolution,  Map<String, Dependency>? dependencies)?  $default,) {final _that = this;
switch (_that) {
case _Catalog() when $default != null:
return $default(_that.environment,_that.version,_that.publishTo,_that.homepage,_that.repository,_that.issueTracker,_that.topics,_that.documentation,_that.funding,_that.platforms,_that.resolution,_that.dependencies);case _:
  return null;

}
}