#482 path grammar

shacl12-core/images/Makefile

@@ -0,0 +1,4 @@
+all: SHACL-UML.svg path-EBNF.svg
+
+%.svg: %.puml
+	plantuml -Tsvg $^

shacl12-core/images/SHACL-UML.puml

@@ -0,0 +1,54 @@
+@startuml
+hide circles
+hide empty members
+skinparam pathHoverColor red ' on cover, highlight blue links as red
+' skinparam topurl https://raw.githack.com/w3c/data-shapes/master/shacl12-core/index.html ' links resolve to anchors in current HTML page, when the SVG is embedded
+
+class "<color:blue><u>sh:Shape" as Shape [[#shapes]] {
+  [[#targetClass sh:targetClass]] : rdfs:Class
+  [[#targetNode sh:targetNode]] : any
+  [[#targetSubjectsOf sh:targetSubjectsOf]] : rdf:Property
+  [[#targetObjectsOf sh:targetObjectsOf]] : rdf:Property
+  ....
+  [[#deactivated sh:deactivated]] : xsd:boolean
+  [[#message sh:message]] : xsd:string or rdf:langString
+  [[#severity sh:severity]] : sh:Severity
+}
+
+class "<color:blue><u>sh:NodeShape" as NodeShape [[#node-shapes]] {
+  [[#constraints Constraint parameters]], for example:
+  [[#NodeKindConstraintComponent sh:nodeKind]] a sh:NodeKind
+  [[#ClosedConstraintComponent sh:closed]] : xsd:boolean or [[#syntax-rule-closed-datatype sh:ByTypes]]
+  [[#ClosedConstraintComponent sh:ignoredProperties]] : list
+  [[#OrConstraintComponent sh:or]], [[#AndConstraintComponent sh:and]], [[#XoneConstraintComponent sh:xone]] : list of Shape
+  [[#NotConstraintComponent sh:not]] : [[#shapes sh:Shape]]
+  ...
+}
+
+class "<color:blue><u>sh:PropertyShape" as PropertyShape [[#property-shapes]] {
+  [[#constraints Constraint parameters]], for example:
+  [[#MinCountConstraintComponent sh:minCount]], [[#MaxCountConstraintComponent sh:maxCount]] : xsd:integer
+  [[#MinLengthConstraintComponent sh:minLength]], [[#MaxLengthConstraintComponent sh:maxLength]] : xsd:integer
+  [[#ClassConstraintComponent sh:class]] or [[#DatatypeConstraintComponent sh:datatype]] : IRI or list of IRIs
+  [[#NodeConstraintComponent sh:node]] : [[#node-shapes sh:NodeShape]]
+  ...
+  ....
+  [[#name sh:name]] : xsd:string or rdf:langString
+  [[#description sh:description]] : xsd:string or rdf:langString
+  [[#syntax-rule-path-defaultValue sh:defaultValue]] : any
+  [[#syntax-rule-path-defaultValue sh:values]] : any
+  [[#codeIdentifier sh:codeIdentifier]] : xsd:string 
+  [[#order sh:order]] : xsd:integer or xsd:decimal
+  [[#property-paths sh:path]] : predicate or list or blank node
+}
+
+class "<color:blue><u>sh:PropertyGroup" as PropertyGroup [[#group sh:group]] {
+  [[#group sh:order]] : xsd:integer or xsd:decimal
+  ... eg rdfs:label
+}
+
+Shape <|-- NodeShape
+Shape <|-- PropertyShape
+NodeShape -> PropertyShape : [[#property-shapes sh:property]] *
+PropertyShape --> PropertyGroup :  [[#group sh:group]]
+@enduml

shacl12-core/images/path-EBNF-rr.txt

@@ -0,0 +1,6 @@
+/* https://www.bottlecaps.de/rr/ui : check SVG, uncheck Embedded */
+
+path ::= predicate | 
+  '(' path* ')' | 
+  '[' ('sh:inversePath'|'sh:alternativePath'|'sh:zeroOrOnePath'|'sh:zeroOrMorePath'|'sh:oneOrMorePath') path ']'
+

shacl12-core/images/path-EBNF.puml

@@ -0,0 +1,3 @@
+@startEbnf
+path = predicate | "(", {path}-, ")" | "[", ("sh:inversePath"|"sh:alternativePath"|"sh:zeroOrOnePath"|"sh:zeroOrMorePath"|"sh:oneOrMorePath"), path, "]" ;
+@endEbnf

shacl12-core/index.html

@@ -2379,7 +2379,12 @@ <h2>SHACL Property Paths</h2>
 				SHACL includes RDF terms to represent the following subset of <a>SPARQL property paths</a>:
 				<code>PredicatePath</code>, <code>InversePath</code>, <code>SequencePath</code>, <code>AlternativePath</code>,
 				<code>ZeroOrMorePath</code>, <code>OneOrMorePath</code> and <code>ZeroOrOnePath</code>.
+        This syntax diagram shows how they can be used together
+        (<code>PredicatePath</code> is the basic case consisting of a single predicate,
+        <code>SequencePath</code> uses a parenthesized list of paths,
+        and the rest use a blank node and a specific <code>sh:</code> term):
 			</p>
+      <img src="images/path-EBNF-rr.svg" alt="Railroad grammar diagram of RDF terms to represent property paths">
 			<p>
 				The following sub-sections provide syntax rules of <a>well-formed</a> <a>SHACL property paths</a>
 				together with mapping rules to <a href="https://www.w3.org/TR/sparql12-query/#pp-language">SPARQL 1.2 property paths</a>.

shacl12-vocabularies/shacl-shacl.ttl

@@ -23,11 +23,11 @@ shsh:
 shsh:ListShape
 	a sh:NodeShape ;
 	rdfs:label "List shape"@en ;
-	rdfs:comment "A shape describing well-formed RDF lists. Currently does not check for non-recursion. This could be expressed using SHACL-SPARQL."@en ;
+	rdfs:comment "A shape describing well-formed RDF lists. Currently does not check for non-recursion (this could be expressed using SHACL-SPARQL)."@en ;
 	rdfs:seeAlso <https://www.w3.org/TR/shacl/#syntax-rule-SHACL-list> ;
 	sh:property [
 		sh:path [ sh:zeroOrMorePath rdf:rest ] ;
-		rdfs:comment "Each list member (including this node) must be have the shape shsh:ListNodeShape."@en ;
+		rdfs:comment "Each list member (including this node) must have the shape shsh:ListNodeShape."@en ;
 		sh:hasValue rdf:nil ;
 		sh:node shsh:ListNodeShape ;
 	] .