Gremlin using pipe output as an input again

Question

I have a graph which looks like

a --father_of--> 1 --wife_of--> b --father_of-->2 --wife_of--> c --father_of--> 3--wife_of--> d --father_of --> 5--wife_of-->e

I want to write a query which gives me all fathers in the tree starting from a

I can get to one level by writing

g.V('name','a').out(father_of).out(wife_of) which gives b

How can I write a recursive query giving b as input of the pipe so that the query gives me nodes b, c, d and e.

Answer 1

You can use the loop() and an emit-closure:

g.V('name','a').as('here').out('fatherOf').out('wifeOf').loop('here'){true}{true}