Re: plural properties should become singular

On 1/28/14 12:59 PM, Gregg Kellogg wrote:
> On Jan 28, 2014, at 9:31 AM, Ruben Verborgh<ruben.verborgh@ugent.be>  wrote:
>
>> >Dear all,
>> >
>> >TL;DR: Since the range of the following properties is not a list, I think they should be singular:
>> >- hydra:mappings
>> >- hydra:members
>> >- hydra:operations
>> >- hydra:statusCodes
>> >- hydra:supportedClasses
>> >- hydra:supportedOperations
>> >- hydra:supportedProperties
>> >This mail argues why plural properties are not a good idea.
>> >
>> >In the RDF data model, a property creates a relation between a subject and an object.
>> >For instance, :subject :hasP :object means that “subject has object as P".
>> >We see examples of that in all popular vocabularies. Examples:
>> >RDF – :me rdf:type foaf:Person, foaf:Agent.
>> >FOAF – :me foaf:interest, :Web, :Hypermedia.
>> >Dublin Core – ;document dc:hasPart :part1, :part2.
>> >
>> >As you can see, it doesn't matter whether one or multiple properties are expected:
>> >multiple objects can be attached to the same subject; but all are different relations.
>> >The property is singular because it describes a relation between two (singular) things.
>> >The only time we would encounter a plural, is if the object is a list/collection.
>> >
>> >If we look at Hydra, this is not defined as one would expect:
>> >    {
>> >      "@id": "hydra:mappings",
>> >      "@type": "rdf:Property",
>> >      "comment": "The variable-to-property mappings of the IRI template.",
>> >      "domain": "hydra:IriTemplate",
>> >      "label": "mappings",
>> >      "range": "hydra:IriTemplateMapping",
>> >      "status": "testing"
>> >    },
>> >
>> >This can lead to situations such as
>> >    :Template hydra:template "/issues{?q}" ;
>> >        hydra:mappings :q.
>> >    :q a hydra:IriTemplateMapping;
>> >        hydra:property hydra:freetextQuery;
>> >        hydra:required true;
>> >        hydra:variable "q" .
>> >
>> >So the “mappings” of /issues{?q} is actually a single mapping.
>> >Or in other words: /issues{?q} has "mappings” :q,
>> >but :q is only a single mapping, not a collection of mappings.
>> >Let me trim down the example to show this contradiction better:
>> >    :Template hydra:mappings :q.
>> >    :q a hydra:IriTemplateMapping.
>> >Either :q should be hydra:IriTemplateMappings,
>> >or the property should be singular: "hydra:mapping".
>> >
>> >The case of “statusCodes” shows to how much confusion this leads:
>> >we have both a “statusCode” and a ”statusCodes” property.
>> >The situation would be that a resource can lead to “statusCodes" X, Y, Z,
>> >each of which have a “statusCode” 200, 400, 500, respectively.
>> >I think the correct way is that “statusCodes” becomes “status”,
>> >and that the current statusCode remains the way it is.
>> >
>> >I would strongly suggest that all of the aforementioned properties are turned into singular;
>> >that would align Hydra with the best practices of all other vocabularies.
>> >I know that changing this can be a pain, but I think it's important we do this.
> +1. IMO, best practice for RDF predicate names is to be singular; schema.org made many mistakes in this area, and now there are typically both plural and singular versions which mean the same thing.
>
> Gregg
>
+1

-- 

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