Marko A. Rodriguez created TINKERPOP3-798:
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Summary: [Proposal] Rename mapKeys()/mapValues() to select(keys)
and select(values).
Key: TINKERPOP3-798
URL: https://issues.apache.org/jira/browse/TINKERPOP3-798
Project: TinkerPop 3
Issue Type: Improvement
Components: process
Affects Versions: 3.0.0-incubating
Reporter: Marko A. Rodriguez
Assignee: Marko A. Rodriguez
I don't like the terms {{mapKeys()}} and {{mapValues()}}. I think we should use
"select" as the term for all projections out of a tuple. For instance, we do:
{code}
select('a') // get the object referenced by 'a' out of the incoming map
select('a','b') // get the objects referenced by 'a' and 'b' out of the
incoming map
{code}
{{select()}} can even be used in situations that people don't typically think
to use it.
gremlin> g.V().has('name','Die Hard').groupCount().by('name')
==>[Die Hard:1]
gremlin> g.V().has('name','Die Hard').groupCount().by('name').select('Die Hard')
==>1
gremlin> g.V().hasLabel('movie').groupCount().by('name').select('Die Hard','Toy
Story','Jurassic Park')
==>[Die Hard:1, Toy Story:1, Jurassic Park:1]
{code}
However, this assumes the keys are strings as {{select()}} only takes string
arguments.
I think for all "project scenarios" the term should be "select." Thus, instead
of {{mapKeys()}} and {{mapValues()}}, we have:
{code}
select(keys) : Map -> Set<String>
select(values) : Map -> Collection<Object>
{code}
Moreover, I don't think these should be flatMap steps like {{mapXXX()}} as you
are projecting for EACH map (similar to how {{select('a','b')}} is not a flat
map of a/b entires but maps of a/b entries).
This type of select is different than the others as you are not projecting out
a value for an entry (row + key -> value), but a Collection value for column
(map + key/value -> collection). Regardless, it is still a projection of the
incoming map (or path!).
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