mapOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>({
  1. TResult? string(
    1. ListDataBuilderString<T> value
    )?,
  2. TResult? custom(
    1. ListDataBuilderCustom<T> value
    )?,
})

A variant of map that fallback to returning null.

It is equivalent to doing:

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

Implementation

@optionalTypeArgs TResult? mapOrNull<TResult extends Object?>({TResult? Function( ListDataBuilderString<T> value)?  string,TResult? Function( ListDataBuilderCustom<T> value)?  custom,}){
final _that = this;
switch (_that) {
case ListDataBuilderString() when string != null:
return string(_that);case ListDataBuilderCustom() when custom != null:
return custom(_that);case _:
  return null;

}
}