CODEWITHSUNDEEP
graph-databasesgremlin
Joel V Zachariah
Joel V Zachariah

Reputation: 21

gremlin: limit step vs take step

I am new to gremlin and while referring to this website, I came across take() step. It has the same output as limit() which makes me wonder what is the difference between the two. I am unable to find any clarification regarding this matter. Thanks!

Upvotes: 2

Views: 391

Answers (2)

jbmusso
jbmusso

Reputation: 3456

The limit() step should be used and is, as of TinkerPop 3.4, the canonical way to iterate a Traversal and retrieve the first n elements.

I can't remember why take() was available on Traversal instances at the time of writing of this article. This sounds a bit odd to me; it could be an Iterator (or comparable) interface leaking, but I'll let maintainers comment on this if they read this question.

You'll be safe with limit().

Upvotes: 0

stephen mallette
stephen mallette

Reputation: 46226

Unfortunately that's a bit confusing. take() is not a Gremlin step. It is instead a Groovy function that is being applied to the end of a traversal (which itself is an Iterator). In much the same way that you can use take() at then end of a traversal you can use other Groovy functions:

gremlin> g.V().take(1)
==>v[1]
gremlin> g.V().collect{it.value('name')}
==>marko
==>vadas
==>lop
==>josh
==>ripple
==>peter

Of course, once you use a Groovy function to process the pipeline you can't go back to Gremlin steps:

gremlin> g.V().take(1).out()
No signature of method: org.codehaus.groovy.runtime.DefaultGroovyMethods$TakeIterator.out() is applicable for argument types: () values: []
Possible solutions: sum(), sort(), sort(groovy.lang.Closure), sort(java.util.Comparator), count(java.lang.Object), count(groovy.lang.Closure)
Type ':help' or ':h' for help.
Display stack trace? [yN]

which is why you would prefer limit(1):

gremlin> g.V().limit(1).out()
==>v[3]
==>v[2]
==>v[4]

Of course, if you're not using Groovy and are programming in a Java environment then it would be obvious that take() and other such functions aren't going to be available to you.

Upvotes: 5

Related Questions