when<TResult extends Object?> method

@optionalTypeArgs TResult when<TResult extends Object?>({ required TResult never(), required TResult timeout(int data), required TResult timestamp(int data), })

A switch-like method, using callbacks.

As opposed to map, this offers destructuring. It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case Subclass2(:final field2):
    return ...;
}

Implementation

@optionalTypeArgs TResult when<TResult extends Object?>({required TResult Function()  never,required TResult Function( int data)  timeout,required TResult Function( int data)  timestamp,}) {final _that = this;
switch (_that) {
case ExpirationNever():
return never();case ExpirationTimeout():
return timeout(_that.data);case ExpirationTimestamp():
return timestamp(_that.data);}
}