Shouldn't that be

eval { goto 'L'.($var+0) }; goto L_default;

L10: print "a";
L9: print "b";
L8: print "c";
L7: print "d";
L6: print "e";
L5: print "f";
L4: print "g";
L3: print "h";
L2: print "i";
L1: print "j";
L_default:

print "\n";
[download]

to preserve the semantics of the original code?