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https://issues.apache.org/jira/browse/TINKERPOP-2502?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17269658#comment-17269658
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Stephen Mallette commented on TINKERPOP-2502:
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thanks for the additional explanation. i dont think your suggestion to add
{{GraphTraversalSource.start()}} will work because a blank traversal won't be
rigged up properly to start. Note that there is a difference between
{{GraphTraversal.addV()}} sorts of steps and {{GraphTraversalSource.addV()}}
sorts of steps. Spawn steps in {{GraphTraversalSource}} will add a different
sort of {{addV()}}-step that is designed to trigger the start of the traversal.
Without that trigger nothing happens. your suggested
{{GraphTraversalSource.start()}} would basically just be this:
{code}
return new DefaultGraphTraversal(this.clone());
{code}
so rigged up in the console:
{code}
gremlin> g = TinkerGraph.open().traversal()
==>graphtraversalsource[tinkergraph[vertices:0 edges:0], standard]
gremlin> new DefaultGraphTraversal(g.clone()).addV('person').iterate()
gremlin> g
==>graphtraversalsource[tinkergraph[vertices:0 edges:0], standard]
{code}
I don't think a common interface helps you so well either as {{__}} are static.
I could still be misunderstanding something though....
> Consistent start API for anonymous and regular traversals
> ---------------------------------------------------------
>
> Key: TINKERPOP-2502
> URL: https://issues.apache.org/jira/browse/TINKERPOP-2502
> Project: TinkerPop
> Issue Type: Improvement
> Components: process
> Affects Versions: 3.4.9
> Reporter: Christopher Smith
> Priority: Minor
>
> I am writing a graph-based application and am taking advantage of the
> method-based nature of Gremlin to librarify some of my common usage patterns.
> However, I'm encountering a frustrating problem where I frequently need to be
> able to attach the same traversal steps to either a real
> {{GraphTraversalSource}} or an anonymous traversal (usually for some nested
> reason like a coalesced conditional insert).
> The methods on {{__}} are mostly static, but I can call {{__.start()}} to
> obtain a live {{GraphTraversal}} object and then proceed from there (invoking
> {{GraphTraversal#addV}}, for example). {{GraphTraversalSource}}, however,
> requires me to invoke the method {{GraphTraversalSource#addV}} to get
> started, and there's no common base type. I think I could theoretically use
> something like {{inject()}}, but that seems particularly odd.
> It would be helpful to either have both {{GraphTraversal}} and
> {{GraphTraversalSource}} implement a common interface holding the "start
> opcodes" or to have a {{GraphTraversalSource#start()}} method that could be
> used to obtain a "blank" traversal.
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