Fix for #25 (Broken lambdas due to variable scoping).

Scaseco · Oct 22, 2024 · b436105 · b436105
1 parent 9a41a1e
commit b436105
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Showing 5 changed files with 53 additions and 17 deletions.
diff --git a/...arq-plugins-bundle/src/main/java/org/aksw/jena_sparql_api/sparql/ext/sys/FN_LambdaOf.java b/...arq-plugins-bundle/src/main/java/org/aksw/jena_sparql_api/sparql/ext/sys/FN_LambdaOf.java
@@ -1,27 +1,33 @@
 package org.aksw.jena_sparql_api.sparql.ext.sys;
 
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 
 import org.aksw.jenax.arq.datatype.lambda.Lambda;
 import org.aksw.jenax.arq.datatype.lambda.NodeValueLambda;
 import org.aksw.jenax.arq.util.binding.BindingUtils;
+import org.aksw.jenax.arq.util.expr.ExprUtils;
+import org.aksw.jenax.arq.util.var.VarUtils;
 import org.apache.jena.query.Query;
 import org.apache.jena.query.QueryFactory;
 import org.apache.jena.query.ResultSet;
 import org.apache.jena.query.ResultSetFormatter;
 import org.apache.jena.sparql.core.DatasetGraphFactory;
 import org.apache.jena.sparql.core.Substitute;
 import org.apache.jena.sparql.core.Var;
+import org.apache.jena.sparql.engine.Rename;
 import org.apache.jena.sparql.engine.binding.Binding;
 import org.apache.jena.sparql.exec.QueryExec;
 import org.apache.jena.sparql.expr.Expr;
 import org.apache.jena.sparql.expr.ExprList;
 import org.apache.jena.sparql.expr.NodeValue;
 import org.apache.jena.sparql.function.FunctionBase;
 import org.apache.jena.sparql.function.FunctionEnv;
+import org.apache.jena.sparql.service.enhancer.impl.util.VarScopeUtils;
 
 /**
  * A function that returns an RDF term that encapsulates a lambda.
@@ -85,18 +91,21 @@ public NodeValue exec(Binding binding, ExprList args, String uri, FunctionEnv en
         if (n == 0) {
             throw new RuntimeException("At least 1 argument required which is an expression");
         }
-        List<Expr> el = args.getList();
-        List<Expr> argList = el.subList(0, n - 1);
+        List<Expr> scopedExprs = args.getList();
+        List<Expr> scopedArgList = scopedExprs.subList(0, n - 1);
 
-        List<Var> argVars = argList.stream().map(e -> e.asVar()).collect(Collectors.toList());
-        Set<Var> argVarsSet = new HashSet<>(argVars);
-        Expr rawExpr = el.get(n - 1);
+        List<Var> scopedArgVars = scopedArgList.stream().map(e -> e.asVar()).collect(Collectors.toList());
+        Set<Var> scopedArgVarsSet = new HashSet<>(scopedArgVars);
+        Expr scopedRawExpr = scopedExprs.get(n - 1);
 
         // Remove all argVars from the binding
-        Binding effBinding = BindingUtils.project(binding, binding.vars(), argVarsSet);
-        Expr expr = Substitute.substitute(rawExpr, effBinding);
+        Binding effBinding = BindingUtils.project(binding, binding.vars(), scopedArgVarsSet);
+        Expr scopedExpr = Substitute.substitute(scopedRawExpr, effBinding);
 
-        Lambda lambda = new Lambda(argVars, expr);
+        List<Var> unscopedArgVars = scopedArgVars.stream().map(v -> (Var)Rename.reverseVarRename(v)).toList();
+        Expr unscopedExpr = ExprUtils.reverseVarRename(scopedExpr);
+
+        Lambda lambda = new Lambda(unscopedArgVars, unscopedExpr);
         NodeValue result = new NodeValueLambda(lambda);
         return result;
     }

diff --git a/...lugins-bundle/src/main/java/org/aksw/jena_sparql_api/sparql/ext/sys/JenaExtensionSys.java b/...lugins-bundle/src/main/java/org/aksw/jena_sparql_api/sparql/ext/sys/JenaExtensionSys.java
@@ -10,7 +10,7 @@
 import org.aksw.jenax.arq.functionbinder.FunctionBinder;
 import org.aksw.jenax.arq.functionbinder.FunctionBinders;
 import org.aksw.jenax.norse.term.core.NorseTerms;
-import org.aksw.jenax.norse.term.rdf.NorseTermsLambda;
+import org.aksw.jenax.norse.term.sparql.NorseTermsSparql;
 import org.apache.jena.shared.PrefixMapping;
 import org.apache.jena.sparql.function.FunctionRegistry;
 import org.apache.jena.sparql.pfunction.PropertyFunctionRegistry;
@@ -35,9 +35,14 @@ public static void register() {
         registry.put(ns + "nextLong", E_NextLong.class);
         registry.put(ns + "rscmp", E_CompareResultSet.class);
 
-        registry.put(NorseTermsLambda.fnOf, FN_LambdaOf.class);
-        registry.put(NorseTermsLambda.fnCall, FN_LambdaCall.class);
-        registry.put(NorseTermsLambda.mapComputeIfAbsent, FN_MapComputeIfAbsent.class);
+        // Legacy registrations
+        // registry.put(NorseTermsLambda.fnOf, FN_LambdaOf.class);
+        // registry.put(NorseTermsLambda.fnCall, FN_LambdaCall.class);
+        // registry.put(NorseTermsLambda.mapComputeIfAbsent, FN_MapComputeIfAbsent.class);
+
+        registry.put(NorseTermsSparql.fnOf, FN_LambdaOf.class);
+        registry.put(NorseTermsSparql.fnCall, FN_LambdaCall.class);
+        registry.put(NorseTermsSparql.mapComputeIfAbsent, FN_MapComputeIfAbsent.class);
 
         FunctionBinder binder = FunctionBinders.getDefaultFunctionBinder();
         binder.register(ns + "getenv", System.class, "getenv", String.class);

diff --git a/...plugins-datatypes/src/main/java/org/aksw/jenax/arq/datatype/lambda/RDFDatatypeLambda.java b/...plugins-datatypes/src/main/java/org/aksw/jenax/arq/datatype/lambda/RDFDatatypeLambda.java
@@ -1,11 +1,9 @@
 package org.aksw.jenax.arq.datatype.lambda;
 
+import org.aksw.jenax.norse.term.sparql.NorseTermsSparql;
 import org.apache.jena.datatypes.BaseDatatype;
 import org.apache.jena.datatypes.DatatypeFormatException;
 import org.apache.jena.datatypes.RDFDatatype;
-import org.apache.jena.sparql.expr.Expr;
-import org.apache.jena.sparql.expr.ExprEvalException;
-import org.apache.jena.sparql.util.ExprUtils;
 
 ///**
 // * A datatype for storing SPARQL expressions in RDF literals.
@@ -16,9 +14,12 @@
 public class RDFDatatypeLambda
     extends BaseDatatype
 {
-    public static final String IRI = "http://jsa.aksw.org/dt/sparql/lambda";
+    public static final String IRI = NorseTermsSparql.fn;
     public static final RDFDatatypeLambda INSTANCE = new RDFDatatypeLambda();
 
+    // Legacy IRI
+    // public static final String IRI = "http://jsa.aksw.org/dt/sparql/lambda";
+
     public static RDFDatatype get() {
         return INSTANCE;
     }
@@ -58,4 +59,4 @@ public Lambda parse(String lexicalForm) throws DatatypeFormatException {
         Lambda result = Lambdas.parse(lexicalForm);
         return result;
     }
-}
+}
diff --git a/jenax-arq-parent/jenax-arq-utils/src/main/java/org/aksw/jenax/arq/util/expr/ExprUtils.java b/jenax-arq-parent/jenax-arq-utils/src/main/java/org/aksw/jenax/arq/util/expr/ExprUtils.java
@@ -28,6 +28,7 @@
 import org.apache.jena.graph.NodeFactory;
 import org.apache.jena.sparql.core.Var;
 import org.apache.jena.sparql.core.VarAlloc;
+import org.apache.jena.sparql.engine.Rename;
 import org.apache.jena.sparql.engine.binding.Binding;
 import org.apache.jena.sparql.expr.E_Bound;
 import org.apache.jena.sparql.expr.E_Equals;
@@ -175,6 +176,11 @@ public static Expr applyNodeTransform(Expr expr, NodeTransform xform) {
         return result;
     }
 
+    /** Repeatedly reverse var naming of {@link Rename#renameVars(Expr, Set)}. */
+    public static Expr reverseVarRename(Expr expr) {
+        return applyNodeTransform(expr, Rename::reverseVarRename);
+    }
+
     public static E_OneOf oneOf(Node v, Iterable<Node> args) {
         ExprList el = new ExprList();
         el.addAll(ExprListUtils.nodesToExprs(args));

diff --git a/...nt/jenax-norse-terms/src/main/java/org/aksw/jenax/norse/term/sparql/NorseTermsSparql.java b/...nt/jenax-norse-terms/src/main/java/org/aksw/jenax/norse/term/sparql/NorseTermsSparql.java
@@ -0,0 +1,15 @@
+package org.aksw.jenax.norse.term.sparql;
+
+import org.aksw.jenax.norse.term.core.NorseTerms;
+
+public class NorseTermsSparql {
+    public static final String NS = NorseTerms.NS + "sparql.";
+    public static final String fn = NorseTerms.NS + "fn";
+
+    public static final String fnOf = NorseTerms.NS + "fn.of";
+    public static final String fnCall = NorseTerms.NS + "fn.call";
+
+    // Move to Map
+    public static final String mapComputeIfAbsent = NorseTerms.NS + "map.computeIfAbsent";
+
+}