mapOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>({
  1. TResult? encrypted(
    1. KeySigner_Encrypted value
    )?,
  2. TResult? derived(
    1. KeySigner_Derived value
    )?,
  3. TResult? ledger(
    1. KeySigner_Ledger value
    )?,
  4. TResult? stub(
    1. KeySigner_Stub 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( KeySigner_Encrypted value)?  encrypted,TResult? Function( KeySigner_Derived value)?  derived,TResult? Function( KeySigner_Ledger value)?  ledger,TResult? Function( KeySigner_Stub value)?  stub,}){
final _that = this;
switch (_that) {
case KeySigner_Encrypted() when encrypted != null:
return encrypted(_that);case KeySigner_Derived() when derived != null:
return derived(_that);case KeySigner_Ledger() when ledger != null:
return ledger(_that);case KeySigner_Stub() when stub != null:
return stub(_that);case _:
  return null;

}
}