whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>({
  1. TResult? transfer(
    1. SplTokenTransferInfo info,
    2. String type
    )?,
  2. TResult? transferChecked(
    1. SplTokenTransferCheckedInfo info,
    2. String type
    )?,
  3. TResult? generic(
    1. dynamic info,
    2. String type
    )?,
})

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( SplTokenTransferInfo info,  String type)?  transfer,TResult? Function( SplTokenTransferCheckedInfo info,  String type)?  transferChecked,TResult? Function( dynamic info,  String type)?  generic,}) {final _that = this;
switch (_that) {
case ParsedSplTokenTransferInstruction() when transfer != null:
return transfer(_that.info,_that.type);case ParsedSplTokenTransferCheckedInstruction() when transferChecked != null:
return transferChecked(_that.info,_that.type);case ParsedSplTokenGenericInstruction() when generic != null:
return generic(_that.info,_that.type);case _:
  return null;

}
}