mapOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>({
  1. TResult? slp(
    1. SlpTokenType value
    )?,
  2. TResult? alp(
    1. AlpTokenType value
    )?,
  3. TResult? unknown(
    1. UnknownTokenType 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( SlpTokenType value)?  slp,TResult? Function( AlpTokenType value)?  alp,TResult? Function( UnknownTokenType value)?  unknown,}){
final _that = this;
switch (_that) {
case SlpTokenType() when slp != null:
return slp(_that);case AlpTokenType() when alp != null:
return alp(_that);case UnknownTokenType() when unknown != null:
return unknown(_that);case _:
  return null;

}
}