>more f

%h=(m=>1=>n=>2=>o=>3=>)=>@h{m,n,o}=(4,5,6)=>print%h


>perl -MO=Deparse f
%h = ('m', 1, 'n', 2, 'o', 3), @h{/n/o} = (4, 5, 6), print(%h);
f syntax OK

>perl -w f
Use of uninitialized value in pattern match (m//) at f line 1.
m1n2o3