namespace -> urn

Author: benbellick

core/src/main/java/io/substrait/extension/ImmutableExtensionLookup.java

@@ -41,10 +41,10 @@ public Builder from(ExtendedExpression extendedExpression) {
     private Builder from(
         List<SimpleExtensionURN> simpleExtensionURNs,
         List<SimpleExtensionDeclaration> simpleExtensionDeclarations) {
-      Map<Integer, String> namespaceMap = new HashMap<>();
+      Map<Integer, String> urnMap = new HashMap<>();
       // Handle URN format
       for (SimpleExtensionURN extension : simpleExtensionURNs) {
-        namespaceMap.put(extension.getExtensionUrnAnchor(), extension.getUrn());
+        urnMap.put(extension.getExtensionUrnAnchor(), extension.getUrn());
       }
 
       // Add all functions used in plan to the functionMap
@@ -54,14 +54,14 @@ private Builder from(
         }
         SimpleExtensionDeclaration.ExtensionFunction func = extension.getExtensionFunction();
         int reference = func.getFunctionAnchor();
-        String namespace = namespaceMap.get(func.getExtensionUrnReference());
-        if (namespace == null) {
+        String urn = urnMap.get(func.getExtensionUrnReference());
+        if (urn == null) {
           throw new IllegalStateException(
               "Could not find extension URN for function reference "
                   + func.getExtensionUrnReference());
         }
         String name = func.getName();
-        SimpleExtension.FunctionAnchor anchor = SimpleExtension.FunctionAnchor.of(namespace, name);
+        SimpleExtension.FunctionAnchor anchor = SimpleExtension.FunctionAnchor.of(urn, name);
         functionMap.put(reference, anchor);
       }
 
@@ -72,13 +72,13 @@ private Builder from(
         }
         SimpleExtensionDeclaration.ExtensionType type = extension.getExtensionType();
         int reference = type.getTypeAnchor();
-        String namespace = namespaceMap.get(type.getExtensionUrnReference());
-        if (namespace == null) {
+        String urn = urnMap.get(type.getExtensionUrnReference());
+        if (urn == null) {
           throw new IllegalStateException(
               "Could not find extension URN for type reference " + type.getExtensionUrnReference());
         }
         String name = type.getName();
-        SimpleExtension.TypeAnchor anchor = SimpleExtension.TypeAnchor.of(namespace, name);
+        SimpleExtension.TypeAnchor anchor = SimpleExtension.TypeAnchor.of(urn, name);
         typeMap.put(reference, anchor);
       }