How to get the sum of the nodes() in a path (variable length)

[bbigras]

a -> b -> c -> d

All four of them have value: 1.

I would like to get the sum of all four using (a { name: 'a'})-[*]-(b { name: 'd'}) (which would be 4).

I saw that list comprehensions is not supported yet.

Is there a way, maybe, to get the array as rows or something, where I could only access value?

SELECT create_graph('playground');
SELECT create_vlabel('playground','Thing');
SELECT create_elabel('playground','CHILD_OF');

SELECT * FROM cypher('playground', $$
  CREATE
  (a:Thing { name: 'a', value: 1}),
  (b:Thing { name: 'b', value: 1}),
  (c:Thing { name: 'c', value: 1}),
  (d:Thing { name: 'd', value: 1}),
  (d)-[:CHILD_OF]->(c),
  (c)-[:CHILD_OF]->(b),
  (b)-[:CHILD_OF]->(a)
$$) as (a agtype);

SELECT * FROM cypher('playground', $$
  MATCH p = (a { name: 'a'})-[*]-(b { name: 'd'})
  RETURN nodes(p)
$$) as (nodes agtype);

I get:

[{"id": 844424930131969, "label": "Thing", "properties": {"name": "a", "value": 1}}::vertex, {"id": 844424930131970, "label": "Thing", "properties": {"name": "b", "value": 1}}::vertex, {"id": 844424930131971, "label": "Thing", "properties": {"name": "c", "value": 1}}::vertex, {"id": 844424930131972, "label": "Thing", "properties": {"name": "d", "value": 1}}::vertex]

but I would like to have the sum, or maybe 4 rows.

EDIT: or maybe if I could cast the agtype to a postgresql array somehow.