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https://issues.apache.org/jira/browse/TINKERPOP-968?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15126331#comment-15126331
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Marko A. Rodriguez commented on TINKERPOP-968:
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First, we would not do this as this is not in the conventional language scope:
{code}
g.V().hasLabel('A').out(true, 'ab').out(true, 'bc')
{code}
For your next representation:
{code}
g.V().hasLabel('A').optional(out('ab')).optional(out('bc'))
{code}
depending on the semantics of optional, it would be either of the two:
{code}
g.V().hasLabel('A').coalesce(out('ab'),identity()).coalesce(out('bc'),identity())
{code}
or
{code}
g.V().hasLabel('A').union(out('ab'),identity()).union(out('bc'),identity())
{code}
> Add first class support for an optional traversal
> -------------------------------------------------
>
> Key: TINKERPOP-968
> URL: https://issues.apache.org/jira/browse/TINKERPOP-968
> Project: TinkerPop
> Issue Type: Improvement
> Components: process
> Affects Versions: 3.1.0-incubating
> Reporter: pieter martin
>
> Both SparQL and Cypher use the "Optional" keyword to indicate an optional
> traversal. SQL uses the "left join".
> Gremlin has no first class support for an optional traversal. It can be
> achieved with the choose step but it is verbose, unintuitive and not what the
> choose step is intended for.
> The benefits of optional traversals are many. In particular it makes it
> trivial to load complete subgraphs/trees with one easy to read intuitive
> gremlin statement.
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