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https://issues.apache.org/jira/browse/TINKERPOP-968?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15169293#comment-15169293
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Daniel Kuppitz commented on TINKERPOP-968:
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Aren't you talking about 2 different scenarios? Only a nested {{optional()}}
would be compiled to a nested {{choose()}}, no?
{code}
g.V().optional(out("knows")).optional(out("created")).path()
// would be the same as:
g.V().choose(out("knows"), out("knows"), identity()).
choose(out("created"), out("created"), identity()).path()
{code}
and
{code}
g.V().optional(out("knows").optional(out("created"))).path()
// would be the same as:
g.V().choose(out("knows").choose(out("created"), out("created"), identity()),
out("knows").choose(out("created"), out("created"), identity()),
identity())).path()
{code}
Thus whether {{choose()}} is nested or not, would depend on how/where you use
{{optional()}}
> 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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