[
https://issues.apache.org/jira/browse/TINKERPOP-800?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Stephen Mallette reopened TINKERPOP-800:
----------------------------------------
Assignee: (was: Marko A. Rodriguez)
Decided to reopen this old guy. Doing some things to improve error messages and
realize I'm taking a piecemeal approach to what is basically this concept. Not
sure that it needs to be implemented exactly this way but having something that
can generally validate modulators would go a long way with the problems we have
with error messaging.
> [Proposal] Domain/Range checking during traversal construction.
> ---------------------------------------------------------------
>
> Key: TINKERPOP-800
> URL: https://issues.apache.org/jira/browse/TINKERPOP-800
> Project: TinkerPop
> Issue Type: Improvement
> Components: process
> Affects Versions: 3.0.2-incubating
> Reporter: Marko A. Rodriguez
> Priority: Major
> Labels: breaking
>
> I think we should add two new methods to {{Step}}.
> {code}
> Step.getDomain() -> Class
> Step.getRange() -> Class
> {code}
> Now, when someone does:
> {code}
> g.V().out()
> {code}
> {{GraphStep}} will report that its range is {{Vertex.class}}. {{VertexStep}}
> will report its domain to be {{Vertex.class}}. Good. No typing issues.
> However, when you do this:
> {code}
> g.E().out()
> {code}
> {{GraphStep}} will report that its range is {{Edge.class}}. {{VertexStep}}
> will report its domain to be {{Vertex.class}} --- {{IllegalArgumentException:
> "The provided traversal has an illegal function composition."}}.
> Why is this good -- much better than getting random {{ClassCastExceptions}}
> at execution time.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
