Gizmo

Gremlin language query builder for Go.

This is a work in progress for now. At the moment, this package can only be used for generating Gremlin query strings.

The Logic

Let me know if the package is missing any Traversal steps. Which I'm sure it is.

The basic idea is to have a starting point for a gremlin query and then append a sequence of steps to the end.

Installation

go get github.com/scigno/gizmo

Getting started

Lets say that we have a query like this:

g.V().hasLabel('user')

The query has as a starting point the character 'g'. Then, V() is appended, then finally hasLabel('user'). There are two ways to start a query:

g := gizmo.NewGraph()
or
g := gizmo.G()

This results in a Traversal that has 'g' as the start/head of the query.

Now that we know how to start the query, we can continue with the rest of the query

g.V().HasLabel("user)

You can also pass a parameter.

g := gizmo.NewGraph("x")
or
g := gizmo.G("x")

Which results in a Traversal that begins with 'x'. The character 'g' is the default when a parameter is ommitted.

Now for a more complex example. Let's say we want to create the query bellow.

We want to create a vertex 'product' for a particular user if it does not exist, then create an edge from the user to the product. But if the product exists, return the product vertex.

g.V().has('product', 'productName', 'camera').fold().
coalesce(
	unfold(), 
	addV('product').
		property('productName', 'camera').
		property('createdBy', '12345').
		property('modifiedBy', '12345').
		property('createdOn', 1570288181201).
		property('modifiedOn', 1570288181201).
		as('p').project('p').
		V().has('user', 'userId', '12345').as('u').
		addE('has').from('u').to('p').
		select('p'))

The Graph object generates a new Traversal with a starting point of 'g'

g := gizmo.NewGraph()
g.V().Has("product", "productName", "camera").Fold().
	Coalesce(
		gizmo.Unfold(),
		gizmo.AddV("product").
			Property("productName", "camera").
			Property("createdBy", "12345").
			Property("modifiedBy", "12345").
			Property("createdOn", time.Now().UnixNano()/1000000).
			Property("modifiedOn", time.Now().UnixNano()/1000000).
			As("p").Project("p").
			V().Has("user", "userId", "12345").As("u").
			AddE("has").From("u").To("p").
			Select("p"),
	)

In this other example, we can separate the quey in two steps since the steps are always added to the end of the Traversal

vals := []string{"one", "two"}
ids := []float32{1, 2}
g := gizmo.G()
g.V().Has("user", "userId", "1968410f-a76c-4827-a0cc-4126dcd95590").
	OutE("has").InV().HasLabel("attribute").Order().By("name")
g.Or(gizmo.Has("values", gizmo.Within(vals)), gizmo.Has("ids", gizmo.Within(ids)))

This results in the following query

g.V().has('user', 'userId', '1968410f-a76c-4827-a0cc-4126dcd95590').
	outE('has').inV().hasLabel('attribute').order().by('name').
	or(has('values', within('one', 'two')), has('ids', within(1, 2)))
)

You can find more examples in the example folder.

TODO

• Incorporate the ability to use a Gremlin language driver.
• Complete unit testing