GitHub user okram opened a pull request: https://github.com/apache/tinkerpop/pull/482
TINKERPOP-1541: Select should default to Pop.last semantics https://issues.apache.org/jira/browse/TINKERPOP-1541 All `Scoping` steps use `Pop.last` semantics (`where()`, `match()`, `dedup()`), except `select()` which uses `Pop.mixed`. This is a wart from TinkerPop2 days. I changed `select()` to default to `Pop.last` and provided a `selectV3d0()` backwards compatibility step (@spmallette -- is that how we should name it? or is it `selectV3d2()` now?). The benefit of this is that we can now introduce a simpler `Path` data structure if a traversal is all `Path.last` (which is 99% of traversals out there). That is, if the traversal requirements is `LABELED_PATH` and all pops are `Pop.last`, then we don't need to store "historic" path elements and can have a `MapPath` which is backed by a `Map<String,Object>`. Less data and a simpler/faster equality test for bulking. @robertdale -- ``` gremlin> g.V(1).as('a').select(mixed,'a').as('a').select(mixed,'a') ==>[v[1],v[1]] gremlin> g.V(1).as('a').select('a').as('a').select('a') ==>v[1] ``` VOTE +1. You can merge this pull request into a Git repository by running: $ git pull https://github.com/apache/tinkerpop TINKERPOP-1541 Alternatively you can review and apply these changes as the patch at: https://github.com/apache/tinkerpop/pull/482.patch To close this pull request, make a commit to your master/trunk branch with (at least) the following in the commit message: This closes #482 ---- commit 2d147bf8ef2c3f79a8015632c85a8a01a679f2fd Author: Marko A. Rodriguez <okramma...@gmail.com> Date: 2016-11-08T14:01:19Z Pop.mixed introduced to replace using a null Pop argument. SelectOneStep and SelectStep now default to using Pop.last instead of Pop.mixed. All other Scoping steps already use Pop.last semantics. This change will allow us to introduce a simpler Path data structure for LABELED_PATH traversals with complete Pop.last semantics (99 percent of uses). ---- --- If your project is set up for it, you can reply to this email and have your reply appear on GitHub as well. If your project does not have this feature enabled and wishes so, or if the feature is enabled but not working, please contact infrastructure at infrastruct...@apache.org or file a JIRA ticket with INFRA. ---