Read a file line by line

The lines method is lazy so the following code does indeed read the file line by line, and not all at once.

for open('test.txt').lines
{
  .say
}

In order to be more explicit about the file being read on line at a time, one can write:

my $f = open 'test.txt';
while my $line = $f.get {
    say $line;
}