GH-3888: SHACL list constraints

jena-shacl/src/main/java/org/apache/jena/shacl/engine/constraint/ListMaxLength.java

@@ -30,12 +30,19 @@
 import org.apache.jena.shacl.parser.ConstraintVisitor;
 import org.apache.jena.shacl.validation.ReportItem;
 import org.apache.jena.shacl.vocabulary.SHACL;
+import org.apache.jena.system.GList;
+import org.apache.jena.system.RDFDataException;
 
 /** sh:memberShape */
 
 public class ListMaxLength extends ConstraintList {
 
-    public ListMaxLength(Node node) {}
+    private final long maxLength;
+
+    public ListMaxLength(int maxLength) {
+        this.maxLength = maxLength;
+    }
+
 
     @Override
     public void visit(ConstraintVisitor visitor){
@@ -48,8 +55,19 @@ public void printCompact(IndentedWriter out, NodeFormatter nodeFmt) {
     }
 
     @Override
-    protected ReportItem validateList(ValidationContext vCxt, Graph data, Node headNode) {
-        throw new NotImplemented();
+    protected ReportItem validateList(ValidationContext vCxt, Graph data, Node listNode) {
+        try {
+            GList.isWellformedListEx(data, listNode);
+        } catch (RDFDataException ex) {
+            return new ReportItem(ex.getMessage());
+        }
+
+        long listLength = GList.listLength(data, listNode);
+        if ( listLength > maxLength ) {
+            String msg = toString()+": Invalid list length: expected max "+maxLength+": Got length = "+listLength;
+            return new ReportItem(msg);
+        }
+        return null;
     }
 
     @Override

jena-shacl/src/main/java/org/apache/jena/shacl/engine/constraint/ListMemberShape.java

@@ -37,8 +37,8 @@
 import org.apache.jena.shacl.validation.ReportItem;
 import org.apache.jena.shacl.validation.ValidationProc;
 import org.apache.jena.shacl.vocabulary.SHACL;
-import org.apache.jena.sparql.util.graph.GNode;
-import org.apache.jena.sparql.util.graph.GraphList;
+import org.apache.jena.system.GList;
+import org.apache.jena.system.RDFDataException;
 
 /** sh:memberShape */
 
@@ -61,22 +61,37 @@ public void printCompact(IndentedWriter out, NodeFormatter nodeFmt) {
     }
 
     @Override
-    protected ReportItem validateList(ValidationContext vCxt, Graph data, Node headNode) {
+    protected ReportItem validateList(ValidationContext vCxt, Graph data, Node listNode) {
         Shape memberShape = vCxt.getShapes().getShape(shape);
         if ( memberShape == null ) {
             // XXX
             //vCxt.reportEntry(, shape, focusNode, path, valueNode, constraint);
             // No shape. Error?
             return null;
         }
-        // XXX Check for valid lists.
-        GNode gNode = GNode.create(data, headNode);
-        List<Node> members = GraphList.members(gNode);
+        // Checks for valid lists.
+        List<Node> members;
+        try {
+            members = GList.members(data, listNode);
+        } catch (RDFDataException ex) {
+            String errMsg = ex.getMessage();
+            return new ReportItem(errMsg);
+        }
 
+        // DRY : execute in isolated context e.g. sh:xone (etc), sh:node, QualifiedValueShape,
+        ValidationContext vCxt2 = ValidationContext.create(vCxt);
+        // XXX Isolate validation and wrap violations?
+        // 1 - ensure the base focusNode
+        // 2 - stop at first violation?
         members.forEach(x->{
-            ValidationProc.execValidateShape(vCxt, data, memberShape, x);
+            ValidationProc.execValidateShape(vCxt2, data, memberShape, x);
         });
-        // XXX Isolate validation and wrap violations?
+        boolean innerConforms = vCxt2.generateReport().conforms();
+        if ( ! innerConforms ) {
+            // XXX sh:detail
+            return new ReportItem("One or more members does not conform to shape "+memberShape);
+        }
+
         return null;
     }
 

jena-shacl/src/main/java/org/apache/jena/shacl/engine/constraint/ListMinLength.java

@@ -30,12 +30,18 @@
 import org.apache.jena.shacl.parser.ConstraintVisitor;
 import org.apache.jena.shacl.validation.ReportItem;
 import org.apache.jena.shacl.vocabulary.SHACL;
+import org.apache.jena.system.GList;
+import org.apache.jena.system.RDFDataException;
 
 /** sh:memberShape */
 
 public class ListMinLength extends ConstraintList {
 
-    public ListMinLength(Node node) { }
+    private final long minLength;
+
+    public ListMinLength(int minLength) {
+        this.minLength = minLength;
+    }
 
     @Override
     public void visit(ConstraintVisitor visitor){
@@ -48,8 +54,19 @@ public void printCompact(IndentedWriter out, NodeFormatter nodeFmt) {
     }
 
     @Override
-    protected ReportItem validateList(ValidationContext vCxt, Graph data, Node headNode) {
-        throw new NotImplemented();
+    protected ReportItem validateList(ValidationContext vCxt, Graph data, Node listNode) {
+        try {
+            GList.isWellformedListEx(data, listNode);
+        } catch (RDFDataException ex) {
+            return new ReportItem(ex.getMessage());
+        }
+
+        long listLength = GList.listLength(data, listNode);
+        if ( listLength < minLength ) {
+            String msg = toString()+": Invalid list length: expected min "+minLength+": Got length = "+listLength;
+            return new ReportItem(msg);
+        }
+        return null;
     }
 
     @Override

jena-shacl/src/main/java/org/apache/jena/shacl/parser/Constraints.java

@@ -109,8 +109,8 @@ public class Constraints {
         dispatch.put( SHACL.closed,            (g, s, p, o) -> new ClosedConstraint(g,s,booleanValue(o)) );
 
         dispatch.put( SHACL.memberShape,       (g, s, p, o) -> new ListMemberShape(o));
-        dispatch.put( SHACL.minListLength,     (g, s, p, o) -> new ListMinLength(o));
-        dispatch.put( SHACL.maxListLength,     (g, s, p, o) -> new ListMaxLength(o));
+        dispatch.put( SHACL.minListLength,     (g, s, p, o) -> new ListMinLength(intValue(o)) );
+        dispatch.put( SHACL.maxListLength,     (g, s, p, o) -> new ListMaxLength(intValue(o)) );
         dispatch.put( SHACL.uniqueMembers,     (g, s, p, o) -> new ListUniqueMembers(o));
 
         // Below