mapOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>({
  1. TResult? solid(
    1. BackgroundFillSolid value
    )?,
  2. TResult? gradient(
    1. BackgroundFillGradient value
    )?,
  3. TResult? freeformGradient(
    1. BackgroundFillFreeformGradient 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(BackgroundFillSolid value)? solid,
  TResult? Function(BackgroundFillGradient value)? gradient,
  TResult? Function(BackgroundFillFreeformGradient value)? freeformGradient,
}) {
  final _that = this;
  switch (_that) {
    case BackgroundFillSolid() when solid != null:
      return solid(_that);
    case BackgroundFillGradient() when gradient != null:
      return gradient(_that);
    case BackgroundFillFreeformGradient() when freeformGradient != null:
      return freeformGradient(_that);
    case _:
      return null;
  }
}