将Gremlin GraphTraversal结果与字符串连接 [英] Concatenate Gremlin GraphTraversal result with string

问题描述

在这个非常简单的示例中，我尝试添加一个新的顶点，该顶点应被标记为现有的顶点，但要附加一些前缀:

In this very simple example I am trying to add a new vertex which should be labeled like an existing vertex but with some prefix attached:

g.V(1).addV('prefix_' + label()).valueMap(true)

我在这里想念什么?显然不是字符串，但是我该如何序列化呢?

What am I missing here? It's clearly not a String, but how would I serialize that?

gremlin> g.V(1).label()
==>Person

gremlin> g.V(1).constant(label())
==>[LabelStep]

推荐答案

今天，Gremlin不提供内置的字符串连接功能.如果这样做的话，那就太好了.这意味着您今天最好的选择是使用内联闭包/lambda.这是一个使用TinkerGraph和航路图的示例.

Gremlin today does not provide a built in string concatenation function. It would be nice if it did. That means your best alternative today is to use an in line closure/lambda. Here is an example using TinkerGraph and the air-routes graph.

gremlin> g.V(3).map {"prefix_" + it.get().label}.as('a').addV(select('a'))
==>v[60867]
gremlin> g.V(60867).label()
==>prefix_airport 

请注意，并非所有的图形数据库都允许闭包，因此不能假定其在启用了TinkerPop的任何Graph DB后端上都可以通用.

Note that not all graph databases allow closures so this cannot be assumed to work universally on any TinkerPop enabled Graph DB backend.

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