[ 
https://issues.apache.org/jira/browse/COMMONSRDF-7?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15611417#comment-15611417
 ] 

ASF GitHub Bot commented on COMMONSRDF-7:
-----------------------------------------

Github user stain commented on the issue:

    https://github.com/apache/incubator-commonsrdf/pull/26
  
    This clarifies immutability of an `RDFTerm` (as it is already implemented) 
and that it can be safely used in say a `Set`.
    
    I added `.equals()` and `.hashCode()` to `RDFTerm` which delegate to `IRI`, 
`BlankNode` and `Literal`.
    
    One questions is if `RDFTerm` class should be restrictive about its 
children being either an `IRI`, `BlankNode` or `Literal` - which would not 
allow like `Variable` we tried in Jena - or multiple inheritance.


> Document that RDFTerm, Triple and Quad are immutable
> ----------------------------------------------------
>
>                 Key: COMMONSRDF-7
>                 URL: https://issues.apache.org/jira/browse/COMMONSRDF-7
>             Project: Apache Commons RDF
>          Issue Type: Improvement
>          Components: api
>            Reporter: Stian Soiland-Reyes (old)
>            Assignee: Stian Soiland-Reyes
>              Labels: discussion, immutable
>             Fix For: 0.3.0
>
>
> From https://github.com/commons-rdf/commons-rdf/issues/57
> ansell:
> {quote}
> As mentioned in #45, should we add a contract requirement that all RDFTerm 
> instances (and Triple?) be implemented as immutable objects?
> https://github.com/commons-rdf/commons-rdf/issues/45
> {quote}
> stain:
> {quote}
> +1, if we say SHOULD. But only the exposed RDFTerm++ methods need to be 
> immutable - so this should probably go into each of their descriptions. So if 
> I have a getDatabaseThingie() method that can be mutable.
> {quote}
> ansell:
> {quote}
> The value of stating that the objects must be immutable is decreased if it 
> only applies to the results of the API methods. A useful goal would be to 
> ensure that the entire object is immutable to give a guarantee about 
> threadsafety, but that may be too much for all implementations to support.
> Just stating that the results of the visible API methods are immutable 
> doesn't help much. It is also not likely to apply to the methods that return 
> Optional, as to enable serialisation, the actual field may not be an Optional 
> itself in most cases.
> {quote}



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to