Gremlin query to order vertices with some locked to specific positions

gremlin> g.V().hasLabel("Category").
......1>       inE("belongsTo").as('a').outV().
......2>       path().
......3>         from('a').
......4>         by(coalesce(values('lockedPosition'),constant(0))).
......5>         by('name').
......6>         fold().
......7>         index().
......8>         unfold().
......9>         order().
.....10>           by(choose(limit(local,1).limit(local,1).is(neq(0)),limit(local,1).limit(local,1),tail(local))).
.....11>           by(limit(local,1),desc).
.....12>         fold().
.....13>         union(range(local,1,-1).unfold(),limit(local,1)).fold().unfold()   
==>[[0,Product6],1]
==>[[0,Product1],2]
==>[[3,Product10],9]
==>[[0,Product7],3]
==>[[0,Product2],4]
==>[[0,Product8],5]
==>[[0,Product3],6]
==>[[7,Product9],7]
==>[[0,Product4],8]
==>[[0,Product5],0]