Improve SHACL schema

[VladimirAlexiev]

https://github.com/admin-shell-io/aas-specs/blob/master/schemas/rdf/shacl-schema.ttl

• remove owl:imports <http://datashapes.org/dash> since it doesn't use DASH shape constructs
• remove owl:imports sh: since it doesn't use shapes from that URL (see https://book.validatingrdf.com/bookHtml011.html#sec126)
• remove ^^xs:string since that's default therefore redundant
• maybe rename the ontology URL from aas: to a different one (eg aas-sh:). I personally like the practice to conflate the ontology and shape namespace
• Simplify aas:AbstractLangStringShape as per enable the use of lang tags for langString #382 (comment) (will become sh:datatype rdf:langString in 2 prop shapes). In particular:
  • I doubt this is 100% correct, and there's no need to specify what a lang tag is

    aas-specs/schemas/rdf/shacl-schema.ttl

    Line 39 in 2ab08f9

    sh:pattern "^(([a-zA-Z]{2,3}(-[a-zA-Z]{3}(-[a-zA-Z]{3}){2})?|[a-zA-Z]{4}|[a-zA-Z]{5,8})(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-(([a-zA-Z0-9]){5,8}|[0-9]([a-zA-Z0-9]){3}))*(-[0-9A-WY-Za-wy-z](-([a-zA-Z0-9]){2,8})+)*(-[xX](-([a-zA-Z0-9]){1,8})+)?|[xX](-([a-zA-Z0-9]){1,8})+|((en-GB-oed|i-ami|i-bnn|i-default|i-enochian|i-hak|i-klingon|i-lux|i-mingo|i-navajo|i-pwn|i-tao|i-tay|i-tsu|sgn-BE-FR|sgn-BE-NL|sgn-CH-DE)|(art-lojban|cel-gaulish|no-bok|no-nyn|zh-guoyu|zh-hakka|zh-min|zh-min-nan|zh-xiang)))$" ;

  • This is wrong, since if a node doesn't ever have aas:AbstractLangString, that node shape won't have any effect

    aas-specs/schemas/rdf/shacl-schema.ttl

    Line 29 in 2ab08f9

    FILTER (?type = aas:AbstractLangString)

• Don't use SHACL Advanced because it's more expensive. You can use a single SHACL standard shape for all "abstract class. Please use one of the subclasses". But if you want to target by these abstract classes (aas:AbstractLangString, aas:HasDataSpecificationShape etc), you need to mandate RDFS subclass reasoning, and complicate the shape to look for some rdf:type outside of the list:

aas:NoAbstractClassShape a sh:NodeShape ;
  sh:targetClass aas:DataElement,  aas:DataSpecificationContent, aas:EventElement, ...;
  sh:not [sh:path rdf:type; sh:in (aas:DataElement aas:DataSpecificationContent aas:EventElement ...)];
  sh:message "This is an abstract class. Please use one of the subclasses for the generation of instances."@en.

• Remove this first pattern wherever possible. It says "only printable Unicode chars" and most of the time is redundant (eg digits are printable chars)

  aas-specs/schemas/rdf/shacl-schema.ttl

  Lines 63 to 64 in 2ab08f9

  	sh:pattern "^[\\x09\\x0A\\x0D\\x20-\\uD7FF\\uE000-\\uFFFD\\U00010000-\\U0010FFFF]*$" ;
  	sh:pattern "^(0|[1-9][0-9]*)$" ;

• Declaring a shape subClassOf another shape is questionable at best (a Shape is not a Class, so it cannot be a subClass). What is the purpose of this? (shapes are not inherited this way)

  aas-specs/schemas/rdf/shacl-schema.ttl

  Line 54 in 2ab08f9

  rdfs:subClassOf aas:HasDataSpecificationShape ;