when<TResult extends Object?> method

  1. @optionalTypeArgs
TResult when<TResult extends Object?>({
  1. required TResult success(
    1. T data
    ),
  2. required TResult failure(
    1. FxError error
    ),
})

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( T data)  success,required TResult Function( FxError error)  failure,}) {final _that = this;
switch (_that) {
case FxSuccess():
return success(_that.data);case FxFailure():
return failure(_that.error);}
}