[jira] [Commented] (TINKERPOP-3015) Use wildcard instead of Object for hasId predicates
[
https://issues.apache.org/jira/browse/TINKERPOP-3015?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17876107#comment-17876107
]
Christopher Smith commented on TINKERPOP-3015:
--
Commenting because I'm still running into this problem in new code with 3.7.2;
I get the following compilation error (which correctly implements the generic
semantics):
{code}
[Static type checking] - Cannot call
org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal#hasId(org.apache.tinkerpop.gremlin.process.traversal.P)
with arguments
[org.apache.tinkerpop.gremlin.process.traversal.P]
{code}
> Use wildcard instead of Object for hasId predicates
> ---
>
> Key: TINKERPOP-3015
> URL: https://issues.apache.org/jira/browse/TINKERPOP-3015
> Project: TinkerPop
> Issue Type: Improvement
> Components: process
>Affects Versions: 3.5.7, 3.6.5
>Reporter: Christopher Smith
>Priority: Minor
>
> From both {{GraphTraversal}} and {{__}}, the {{hasId(P)}} steps specify a
> {{P}}. Common predicates, such as {{within}}, propagate the generic
> type from their own arguments, so that this produces a compile-time error:
> {code}
> Collection ids = ...
> g.V().hasId(P.within(ids))
> {code}
> I believe that without loss of safety, the signature in both locations could
> be changed to {{P}}, making the typical case of "here's a collection of
> IDs of known type" work smoothly.
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[jira] [Commented] (TINKERPOP-3015) Use wildcard instead of Object for hasId predicates
[
https://issues.apache.org/jira/browse/TINKERPOP-3015?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17798360#comment-17798360
]
Christopher Smith commented on TINKERPOP-3015:
--
That's exactly what I meant: The _implementation_ has a (kinda hacky) check to
see if it is, but the actual API specification says that that method, which has
a binary name, does something else. Updating the signature from {{P}}
to {{P}} would align the specification and the ABI correctly.
> Use wildcard instead of Object for hasId predicates
> ---
>
> Key: TINKERPOP-3015
> URL: https://issues.apache.org/jira/browse/TINKERPOP-3015
> Project: TinkerPop
> Issue Type: Improvement
>Affects Versions: 3.5.7, 3.6.5
>Reporter: Christopher Smith
>Priority: Minor
>
> From both {{GraphTraversal}} and {{__}}, the {{hasId(P)}} steps specify a
> {{P}}. Common predicates, such as {{within}}, propagate the generic
> type from their own arguments, so that this produces a compile-time error:
> {code}
> Collection ids = ...
> g.V().hasId(P.within(ids))
> {code}
> I believe that without loss of safety, the signature in both locations could
> be changed to {{P}}, making the typical case of "here's a collection of
> IDs of known type" work smoothly.
--
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[jira] [Commented] (TINKERPOP-3015) Use wildcard instead of Object for hasId predicates
[
https://issues.apache.org/jira/browse/TINKERPOP-3015?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17798353#comment-17798353
]
Valentyn Kahamlyk commented on TINKERPOP-3015:
--
now it's equivalent
https://github.com/apache/tinkerpop/blob/master/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal.java#L2382
> Use wildcard instead of Object for hasId predicates
> ---
>
> Key: TINKERPOP-3015
> URL: https://issues.apache.org/jira/browse/TINKERPOP-3015
> Project: TinkerPop
> Issue Type: Improvement
>Affects Versions: 3.5.7, 3.6.5
>Reporter: Christopher Smith
>Priority: Minor
>
> From both {{GraphTraversal}} and {{__}}, the {{hasId(P)}} steps specify a
> {{P}}. Common predicates, such as {{within}}, propagate the generic
> type from their own arguments, so that this produces a compile-time error:
> {code}
> Collection ids = ...
> g.V().hasId(P.within(ids))
> {code}
> I believe that without loss of safety, the signature in both locations could
> be changed to {{P}}, making the typical case of "here's a collection of
> IDs of known type" work smoothly.
--
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[jira] [Commented] (TINKERPOP-3015) Use wildcard instead of Object for hasId predicates
[
https://issues.apache.org/jira/browse/TINKERPOP-3015?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17798300#comment-17798300
]
Christopher Smith commented on TINKERPOP-3015:
--
There exists a compilation error with that exact code in 3.5, and I suspect it
also exists in 3.6 and 3.7. Specifically, even if your code words by
coincidence, I believe inspecting the generated bytecode (e.g., with {{javap
-v}}) will show that the wrong overload is being selected.
{code}Collection asString = List.of("a", "b");
@SuppressWarnings({ "unchecked", "rawtypes" })
Collection asObject = (Collection) asString;
gts.V().hasId(P.within(asString)).iterate();
gts.V().hasId(P.within(asObject)).iterate();
{code}
correctly produces the following bytecode snippet, where you can see that the
invocation of {{hasId(P)}} is resolved to {{hasId(Object, Object...)}}
{code}
#60 = InterfaceMethodref #61.#63 //
org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal.hasId:(Ljava/lang/Object;[Ljava/lang/Object;)Lorg/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal;
#61 = Class #62 //
org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal
#62 = Utf8
org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal
#63 = NameAndType#64:#65 //
hasId:(Ljava/lang/Object;[Ljava/lang/Object;)Lorg/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal;
#64 = Utf8 hasId
#65 = Utf8
(Ljava/lang/Object;[Ljava/lang/Object;)Lorg/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal;
#66 = InterfaceMethodref #61.#67 //
org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal.iterate:()Lorg/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal;
#67 = NameAndType#68:#69 //
iterate:()Lorg/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal;
#68 = Utf8 iterate
#69 = Utf8
()Lorg/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal;
#70 = InterfaceMethodref #61.#71 //
org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal.hasId:(Lorg/apache/tinkerpop/gremlin/process/traversal/P;)Lorg/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal;
{code}
The fact that this produces the desired results in the current implementation
is an implementation detail and not guaranteed by the API semantics.
> Use wildcard instead of Object for hasId predicates
> ---
>
> Key: TINKERPOP-3015
> URL: https://issues.apache.org/jira/browse/TINKERPOP-3015
> Project: TinkerPop
> Issue Type: Improvement
>Affects Versions: 3.5.7, 3.6.5
>Reporter: Christopher Smith
>Priority: Minor
>
> From both {{GraphTraversal}} and {{__}}, the {{hasId(P)}} steps specify a
> {{P}}. Common predicates, such as {{within}}, propagate the generic
> type from their own arguments, so that this produces a compile-time error:
> {code}
> Collection ids = ...
> g.V().hasId(P.within(ids))
> {code}
> I believe that without loss of safety, the signature in both locations could
> be changed to {{P}}, making the typical case of "here's a collection of
> IDs of known type" work smoothly.
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[jira] [Commented] (TINKERPOP-3015) Use wildcard instead of Object for hasId predicates
[
https://issues.apache.org/jira/browse/TINKERPOP-3015?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17786480#comment-17786480
]
Valentyn Kahamlyk commented on TINKERPOP-3015:
--
Could you share code example with compilation error?
For me works without issues with latest 3.6.x and 3.7.x
{code:java}
Graph graph = TinkerFactory.createModern();
GraphTraversalSource g = graph.traversal();
Collection ids = Arrays.asList("1","2","3");
List vertices = g.V().hasId(P.within(ids)).toList();
System.out.println(vertices);{code}
> Use wildcard instead of Object for hasId predicates
> ---
>
> Key: TINKERPOP-3015
> URL: https://issues.apache.org/jira/browse/TINKERPOP-3015
> Project: TinkerPop
> Issue Type: Improvement
>Affects Versions: 3.5.7, 3.6.5
>Reporter: Christopher Smith
>Priority: Minor
>
> From both {{GraphTraversal}} and {{__}}, the {{hasId(P)}} steps specify a
> {{P}}. Common predicates, such as {{within}}, propagate the generic
> type from their own arguments, so that this produces a compile-time error:
> {code}
> Collection ids = ...
> g.V().hasId(P.within(ids))
> {code}
> I believe that without loss of safety, the signature in both locations could
> be changed to {{P}}, making the typical case of "here's a collection of
> IDs of known type" work smoothly.
--
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(v8.20.10#820010)
