my %hash = =$fh.map: { .split(/\t/, 2).Pair };

##</code><code>##

my %hash = =$fh.map: { my @a = .split(/\t/, 2); @a[0] => @a[1] };

##</code><code>##

my %hash = =$fh.map: { given .split(/\t/, 2) { .[0] => .[1] } };