# Evaluate the 'then' expression if the condition is false.
unless (true) {
    print("bad");
}
unless (false) {
    print("good"); # expect: good
}
# Allow block body.
unless (false) { print("block"); } # expect: block

# Assignment in if condition.
var a = true;
unless (a = false) {
    print(a); # expect: false
}