Query assistance with RepeatUntil

[AnthonyRyck]

Hello,
I would like to make a request with Gremlinq but I am a little lost with RepeatUntil.
This is my Gremlin query

g.V().has('name', 'startStation')
.repeat(out ().simplePath())
.until(has('name', 'StopStation'))
.path().limit(1)

Its to find the best path between 2 stations (Vertex).

var startStation = await _g.V<StationVertex>().Where(x => x.StationName == "nameStart")
								.FirstAsync();
var test = await _g.V(startStation.Id).RepeatUntil(__ => __.Out().SimplePath(),
						__ => __.V<StationVertex>().Where(x => x.StationName == "nameStop").Path().Limit(1));

The result give me just the 2 vertices StationVertex Out on start station.
Thanks for your help.

[danielcweber]

Call Debug() on the query, it'll return a gremlin string. From there you'll find where the difference to your original query is.

[AnthonyRyck]

Thanks for the command :)
And the result :

{
	"Script":
	"V(1092).repeat(__.out().simplePath())
			.until(__.V().hasLabel('StationVertex').has('StationName','Reisen').path().limit(1))
			.project('id','label','properties')
			.by(id)
			.by(label)
			.by(__.properties()
					.group()
					.by(label)
					.by(__.project('id','label','value','properties')
							.by(id)
							.by(label)
							.by(value)
							.by(__.valueMap())
							.fold()))",
	"Bindings":{}
}

[AnthonyRyck]

OK !
This request :

var temtt = await _g.V(startStation.Id)
                .RepeatUntil(__ => __.Out().SimplePath(),
			__ => __.V<StationVertex>().Where(x => x.StationName == "nameStop"))
                .Path().Limit(1);

the result :

V(1092).repeat(__.out().simplePath())
	.until(__.V().hasLabel('StationVertex').has('StationName','nameStop'))
	.path().limit(1)

and what I want :

g.V(1092).repeat(out().simplePath())
.until(has('name', 'StopStation'))
.path().limit(1)

What is "___" ? Can you give me a "definition" ?
sorry for my english

[danielcweber]

__ is the anonymous traversal. It's also a concept in Gremlin (see https://tinkerpop.apache.org/docs/current/reference/). It starts off where the outer traversal left off. As such, your use of __ => __.V<StationVertex>() is in error, it's not in your original query. Just leave it out but use V<StationVertex> at the top of your query instead.

[AnthonyRyck]

Sorry I don't understand when you say: "Just leave it out but use V at the top of your query instead."
Thanks you for your help.
The project is great. I think that when I master the writing, it will be a killing ;)

[danielcweber]

The V<StationVertex> mid-query is not in the original query:

That's why the resulting Gremlin-query differs in exactly that spot!

Try

var temtt = await _g
                .V<StationVertex>(startStation.Id)
                .RepeatUntil(__ => __.Out().SimplePath(),
			__ => __.Where(x => x.StationName == "nameStop"))
                .Path().Limit(1);

instead which should be more what you intended and see what it does.