Gremlin each/filter syntax help

[kantube]

i have

[1, 2, 3, 4].each{g.addEdge(g.v(it), g.v(55), 'Category') }

which works but would like to filter the ids in the array to verify that they have a NodeType property equal to 'Category'

thanks for the help.

[James Thornton]

You can do this...

g.v(1,2,3,4).filter{it.nodeType == 'Category'}.each{ g.addEdge(it, g.v(55), 'Category') }

...or...

Use Groovy's collect method to convert the list of IDs to a list of vertices, and then use Gremlin's Identity pipe to convert the list into a pipe Gremlin can use...

start = [1,2,3,4].collect{ g.v(it) }

categories = start._().filter{ it.nodeType == 'Category' }

categories.each{ g.addEdge(it, g.v(55), 'Category') }

...or as a one liner...

[1,2,3,4].collect{ g.v(it) }._().filter{it.nodeType == 'Category'}.each{ g.addEdge(it, g.v(55), 'Category') }

- James

[kantube]

what version are you able to do

g.v(1,2,3,4).filter{it.nodeType == 'Category'}

when i do this i receive and error  "No signature of method: ..."

i am using Neo4j1.5GA

[Peter Neubauer]

Uh,
that is Gremlin 1.4, packaged in Neo4j 1.6 I think.

Cheers,

/peter neubauer

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[Marko Rodriguez]

For Neo4j 1.5GA, I believe that is running Gremlin 1.3. Thus, you need to do this:

g.v(1,2,3,4)._().filter{it.nodeType == 'Category'}

Also, note that this is faster:

g.v(1,2,3,4)._().filter{it.getProperty('nodeType') == 'Category'}

https://github.com/tinkerpop/gremlin/wiki/Gremlin-Groovy-Path-Optimizations

Good luck,

Marko.

http://markorodriguez.com