Scala MatchError scala.collection.immutable.$colon$colon

I got an error while writing a Scala Combinator Parser:
MatchError: ... scala.collection.immutable.$colon$colon
I didn't understand anything until I found there is a list called "::"
$colon$colon
All that was need was to use .toList to get an ordinary list.

Rachel Maddow on The New York Times article about Khashoggi

Interesting to watch Rachel Maddow talk about New York Times article about Khashoggi citing:

"From Trump's failure to condemn white supremacist violence in Charlotesville to mocking a sexual assault victim, there have been many low points of this presidency. But turning a blind eye to the butchering of a U.S.-based journalist just may be one of the lowest."