#1412 - fix out of memory issues

org.hl7.fhir.dstu3/src/main/java/org/hl7/fhir/dstu3/utils/FHIRPathEngine.java

@@ -37,7 +37,9 @@ import org.hl7.fhir.dstu3.model.TimeType;
 import org.hl7.fhir.dstu3.model.TypeDetails;
 import org.hl7.fhir.dstu3.model.TypeDetails.ProfiledType;
 import org.hl7.fhir.dstu3.utils.FHIRLexer.FHIRLexerException;
-import org.hl7.fhir.dstu3.utils.FHIRPathEngine.IEvaluationContext.FunctionDetails;
+import org.hl7.fhir.dstu3.utils.FHIRPathUtilityClasses.FunctionDetails;
+import org.hl7.fhir.dstu3.utils.FHIRPathUtilityClasses.ExecutionContext;
+import org.hl7.fhir.dstu3.utils.FHIRPathUtilityClasses.ExecutionTypeContext;
 import org.hl7.fhir.exceptions.DefinitionException;
 import org.hl7.fhir.exceptions.FHIRException;
 import org.hl7.fhir.exceptions.PathEngineException;
@@ -93,27 +95,7 @@ public class FHIRPathEngine {
   // if the fhir path expressions are allowed to use constants beyond those defined in the specification
   // the application can implement them by providing a constant resolver
   public interface IEvaluationContext {
-    public class FunctionDetails {
+   
-      private String description;
-      private int minParameters;
-      private int maxParameters;
-      public FunctionDetails(String description, int minParameters, int maxParameters) {
-        super();
-        this.description = description;
-        this.minParameters = minParameters;
-        this.maxParameters = maxParameters;
-      }
-      public String getDescription() {
-        return description;
-      }
-      public int getMinParameters() {
-        return minParameters;
-      }
-      public int getMaxParameters() {
-        return maxParameters;
-      }
-
-    }
 
     /**
      * A constant reference - e.g. a reference to a name that must be resolved in context.
@@ -554,63 +536,6 @@ public class FHIRPathEngine {
       return "";
   }
 
-  private class ExecutionContext {
-    private Object appInfo;
-    private Base resource;
-    private Base context;
-    private Base thisItem;
-    private Map<String, Base> aliases;
-
-    public ExecutionContext(Object appInfo, Base resource, Base context, Map<String, Base> aliases, Base thisItem) {
-      this.appInfo = appInfo;
-      this.context = context;
-      this.resource = resource;
-      this.aliases = aliases;
-      this.thisItem = thisItem;
-    }
-    public Base getResource() {
-      return resource;
-    }
-    public Base getThisItem() {
-      return thisItem;
-    }
-    public void addAlias(String name, List<Base> focus) throws FHIRException {
-      if (aliases == null)
-        aliases = new HashMap<String, Base>();
-      else
-        aliases = new HashMap<String, Base>(aliases); // clone it, since it's going to change
-      if (focus.size() > 1)
-        throw new FHIRException("Attempt to alias a collection, not a singleton");
-      aliases.put(name, focus.size() == 0 ? null : focus.get(0));
-    }
-    public Base getAlias(String name) {
-      return aliases == null ? null : aliases.get(name);
-    }
-  }
-
-  private class ExecutionTypeContext {
-    private Object appInfo;
-    private String resource;
-    private String context;
-    private TypeDetails thisItem;
-
-
-    public ExecutionTypeContext(Object appInfo, String resource, String context, TypeDetails thisItem) {
-      super();
-      this.appInfo = appInfo;
-      this.resource = resource;
-      this.context = context;
-      this.thisItem = thisItem;
-
-    }
-    public String getResource() {
-      return resource;
-    }
-    public TypeDetails getThisItem() {
-      return thisItem;
-    }
-  }
-
   private ExpressionNode parseExpression(FHIRLexer lexer, boolean proximal) throws FHIRLexerException {
     ExpressionNode result = new ExpressionNode(lexer.nextId());
     SourceLocation c = lexer.getCurrentStartLocation();
@@ -1048,7 +973,7 @@ public class FHIRPathEngine {
     } else if (constant.startsWith("%")) {
       return resolveConstant(context, constant);
     } else if (constant.startsWith("@")) {
-      return processDateConstant(context.appInfo, constant.substring(1));
+      return processDateConstant(context.getAppInfo(), constant.substring(1));
     } else {
       return new StringType(constant);
     }
@@ -1081,11 +1006,11 @@ public class FHIRPathEngine {
     else if (s.equals("%ucum"))
       return new StringType("http://unitsofmeasure.org");
     else if (s.equals("%resource")) {
-      if (context.resource == null)
+      if (context.getResource() == null)
         throw new PathEngineException("Cannot use %resource in this context");
-      return context.resource;
+      return context.getResource();
     } else if (s.equals("%context")) {
-      return context.context;
+      return context.getContext();
     } else if (s.equals("%us-zip"))
       return new StringType("[0-9]{5}(-[0-9]{4}){0,1}");
     else if (s.startsWith("%\"vs-"))
@@ -1097,7 +1022,7 @@ public class FHIRPathEngine {
     else if (hostServices == null)
       throw new PathEngineException("Unknown fixed constant '"+s+"'");
     else
-      return hostServices.resolveConstant(context.appInfo, s.substring(1));
+      return hostServices.resolveConstant(context.getAppInfo(), s.substring(1));
   }
 
 
@@ -1776,11 +1701,11 @@ public class FHIRPathEngine {
     else if (s.equals("%ucum"))
       return new TypeDetails(CollectionStatus.SINGLETON, "string");
     else if (s.equals("%resource")) {
-      if (context.resource == null)
+      if (context.getResource() == null)
         throw new PathEngineException("%resource cannot be used in this context");
-      return new TypeDetails(CollectionStatus.SINGLETON, context.resource);
+      return new TypeDetails(CollectionStatus.SINGLETON, context.getResource());
     } else if (s.equals("%context")) {
-      return new TypeDetails(CollectionStatus.SINGLETON, context.context);
+      return new TypeDetails(CollectionStatus.SINGLETON, context.getContext());
     } else if (s.equals("%map-codes"))
       return new TypeDetails(CollectionStatus.SINGLETON, "string");
     else if (s.equals("%us-zip"))
@@ -1794,7 +1719,7 @@ public class FHIRPathEngine {
     else if (hostServices == null)
       throw new PathEngineException("Unknown fixed constant type for '"+s+"'");
     else
-      return hostServices.resolveConstantType(context.appInfo, s);
+      return hostServices.resolveConstantType(context.getAppInfo(), s);
   }
 
 	private List<Base> execute(ExecutionContext context, Base item, ExpressionNode exp, boolean atEntry) throws FHIRException {
@@ -1804,8 +1729,8 @@ public class FHIRPathEngine {
         result.add(item);
     } else
       getChildrenByName(item, exp.getName(), result);
-    if (result.size() == 0 && atEntry && context.appInfo != null) {
+    if (result.size() == 0 && atEntry && context.getAppInfo() != null) {
-      Base temp = hostServices.resolveConstant(context.appInfo, exp.getName());
+      Base temp = hostServices.resolveConstant(context.getAppInfo(), exp.getName());
       if (temp != null) {
         result.add(temp);
       }
@@ -1816,7 +1741,7 @@ public class FHIRPathEngine {
   private TypeDetails executeContextType(ExecutionTypeContext context, String name) throws PathEngineException, DefinitionException {
     if (hostServices == null)
       throw new PathEngineException("Unable to resolve context reference since no host services are provided");
-    return hostServices.resolveConstantType(context.appInfo, name);
+    return hostServices.resolveConstantType(context.getAppInfo(), name);
   }
 
   private TypeDetails executeType(String type, ExpressionNode exp, boolean atEntry) throws PathEngineException, DefinitionException {
@@ -2003,7 +1928,7 @@ public class FHIRPathEngine {
       checkParamTypes(exp.getFunction().toCode(), paramTypes, new TypeDetails(CollectionStatus.SINGLETON, "string"));
       return focus;
     case Custom : {
-      return hostServices.checkFunction(context.appInfo, exp.getName(), paramTypes);
+      return hostServices.checkFunction(context.getAppInfo(), exp.getName(), paramTypes);
     }
     default:
       break;
@@ -2120,7 +2045,7 @@ public class FHIRPathEngine {
       List<List<Base>> params = new ArrayList<List<Base>>();
       for (ExpressionNode p : exp.getParameters())
         params.add(execute(context, focus, p, true));
-      return hostServices.executeFunction(context.appInfo, exp.getName(), params);
+      return hostServices.executeFunction(context.getAppInfo(), exp.getName(), params);
     }
     default:
       throw new Error("not Implemented yet");
@@ -2181,11 +2106,11 @@ public class FHIRPathEngine {
 
 
   private ExecutionContext changeThis(ExecutionContext context, Base newThis) {
-    return new ExecutionContext(context.appInfo, context.resource, context.context, context.aliases, newThis);
+    return new ExecutionContext(context.getAppInfo(), context.getResource(), context.getContext(), context.getAliases(), newThis);
   }
 
   private ExecutionTypeContext changeThis(ExecutionTypeContext context, TypeDetails newThis) {
-    return new ExecutionTypeContext(context.appInfo, context.resource, context.context, newThis);
+    return new ExecutionTypeContext(context.getAppInfo(), context.getResource(), context.getContext(), newThis);
   }
 
 
@@ -2467,13 +2392,13 @@ public class FHIRPathEngine {
         }
         Base res = null;
         if (s.startsWith("#")) {
-          Property p = context.resource.getChildByName("contained");
+          Property p = context.getResource().getChildByName("contained");
           for (Base c : p.getValues()) {
           if (s.equals(c.getIdBase()))
               res = c;
         }
       } else if (hostServices != null) {
-         res = hostServices.resolveReference(context.appInfo, s);
+         res = hostServices.resolveReference(context.getAppInfo(), s);
       }
         if (res != null)
           result.add(res);
@@ -2699,7 +2624,7 @@ public class FHIRPathEngine {
     return makeBoolean(!convertToBoolean(focus));
   }
 
-  public class ElementDefinitionMatch {
+  private class ElementDefinitionMatch {
     private ElementDefinition definition;
     private String fixedType;
     public ElementDefinitionMatch(ElementDefinition definition, String fixedType) {

org.hl7.fhir.dstu3/src/main/java/org/hl7/fhir/dstu3/utils/FHIRPathUtilityClasses.java

@@ -0,0 +1,110 @@
+package org.hl7.fhir.dstu3.utils;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.hl7.fhir.dstu3.model.Base;
+import org.hl7.fhir.dstu3.model.TypeDetails;
+import org.hl7.fhir.exceptions.FHIRException;
+
+public class FHIRPathUtilityClasses {
+
+
+  public static class ExecutionContext {
+    private Object appInfo;
+    private Base resource;
+    private Base context;
+    private Base thisItem;
+    private Map<String, Base> aliases;
+
+    public ExecutionContext(Object appInfo, Base resource, Base context, Map<String, Base> aliases, Base thisItem) {
+      this.appInfo = appInfo;
+      this.context = context;
+      this.resource = resource;
+      this.aliases = aliases;
+      this.thisItem = thisItem;
+    }
+    public Base getResource() {
+      return resource;
+    }
+    public Base getThisItem() {
+      return thisItem;
+    }
+    public void addAlias(String name, List<Base> focus) throws FHIRException {
+      if (aliases == null)
+        aliases = new HashMap<String, Base>();
+      else
+        aliases = new HashMap<String, Base>(aliases); // clone it, since it's going to change
+      if (focus.size() > 1)
+        throw new FHIRException("Attempt to alias a collection, not a singleton");
+      aliases.put(name, focus.size() == 0 ? null : focus.get(0));
+    }
+    public Base getAlias(String name) {
+      return aliases == null ? null : aliases.get(name);
+    }
+    public Object getAppInfo() {
+      return appInfo;
+    }
+    public Base getContext() {
+      return context;
+    }
+    public Map<String, Base> getAliases() {
+      return aliases;
+    }
+    
+  }
+
+  public static class ExecutionTypeContext {
+    private Object appInfo;
+    private String resource;
+    private String context;
+    private TypeDetails thisItem;
+
+
+    public ExecutionTypeContext(Object appInfo, String resource, String context, TypeDetails thisItem) {
+      super();
+      this.appInfo = appInfo;
+      this.resource = resource;
+      this.context = context;
+      this.thisItem = thisItem;
+
+    }
+    public String getResource() {
+      return resource;
+    }
+    public TypeDetails getThisItem() {
+      return thisItem;
+    }
+    public Object getAppInfo() {
+      return appInfo;
+    }
+    public String getContext() {
+      return context;
+    }
+    
+    
+  }
+
+  public static class FunctionDetails {
+    private String description;
+    private int minParameters;
+    private int maxParameters;
+    public FunctionDetails(String description, int minParameters, int maxParameters) {
+      super();
+      this.description = description;
+      this.minParameters = minParameters;
+      this.maxParameters = maxParameters;
+    }
+    public String getDescription() {
+      return description;
+    }
+    public int getMinParameters() {
+      return minParameters;
+    }
+    public int getMaxParameters() {
+      return maxParameters;
+    }
+
+  }
+}

org.hl7.fhir.dstu3/src/main/java/org/hl7/fhir/dstu3/utils/StructureMapUtilities.java

@@ -108,6 +108,7 @@ import org.hl7.fhir.dstu3.model.ValueSet.ValueSetExpansionContainsComponent;
 import org.hl7.fhir.dstu3.terminologies.ValueSetExpander.ValueSetExpansionOutcome;
 import org.hl7.fhir.dstu3.utils.FHIRLexer.FHIRLexerException;
 import org.hl7.fhir.dstu3.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.dstu3.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.exceptions.DefinitionException;
 import org.hl7.fhir.exceptions.FHIRException;
 import org.hl7.fhir.exceptions.FHIRFormatError;

org.hl7.fhir.dstu3/src/test/java/org/hl7/fhir/dstu3/test/SnapShotGenerationTests.java

@@ -31,6 +31,7 @@ import org.hl7.fhir.dstu3.test.support.TestingUtilities;
 import org.hl7.fhir.dstu3.utils.CodingUtilities;
 import org.hl7.fhir.dstu3.utils.FHIRPathEngine;
 import org.hl7.fhir.dstu3.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.dstu3.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.exceptions.DefinitionException;
 import org.hl7.fhir.exceptions.FHIRException;
 import org.hl7.fhir.exceptions.FHIRFormatError;

org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/utils/FHIRPathEngine.java

@@ -56,7 +56,10 @@ import org.hl7.fhir.r4.model.TypeDetails;
 import org.hl7.fhir.r4.model.TypeDetails.ProfiledType;
 import org.hl7.fhir.r4.model.ValueSet;
 import org.hl7.fhir.r4.utils.FHIRLexer.FHIRLexerException;
-import org.hl7.fhir.r4.utils.FHIRPathEngine.IEvaluationContext.FunctionDetails;
+import org.hl7.fhir.r4.utils.FHIRPathUtilityClasses.FHIRConstant;
+import org.hl7.fhir.r4.utils.FHIRPathUtilityClasses.ClassTypeInfo;
+import org.hl7.fhir.r4.utils.FHIRPathUtilityClasses.TypedElementDefinition;
+import org.hl7.fhir.r4.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.utilities.CommaSeparatedStringBuilder;
 import org.hl7.fhir.utilities.MergedList;
 import org.hl7.fhir.utilities.MergedList.MergeNode;
@@ -110,167 +113,6 @@ public class FHIRPathEngine {
   private enum Equality {
     Null, True, False
   }
-
-  private class FHIRConstant extends Base {
-
-    private static final long serialVersionUID = -8933773658248269439L;
-    private String value;
-
-    public FHIRConstant(String value) {
-      this.value = value;
-    }
-
-    @Override
-    public String fhirType() {
-      return "%constant";
-    }
-
-    @Override
-    protected void listChildren(List<Property> result) {
-    }
-
-    @Override
-    public String getIdBase() {
-      return null;
-    }
-
-    @Override
-    public void setIdBase(String value) {
-    }
-
-    public String getValue() {
-      return value;
-    }
-
-    @Override
-    public String primitiveValue() {
-      return value;
-    }
-
-    @Override
-    public Base copy() {
-      throw new Error("Not Implemented");
-    }
-
-  }
-
-  private class ClassTypeInfo extends Base {
-    private static final long serialVersionUID = 4909223114071029317L;
-    private Base instance;
-
-    public ClassTypeInfo(Base instance) {
-      super();
-      this.instance = instance;
-    }
-
-    @Override
-    public String fhirType() {
-      return "ClassInfo";
-    }
-
-    @Override
-    protected void listChildren(List<Property> result) {
-    }
-
-    @Override
-    public String getIdBase() {
-      return null;
-    }
-
-    @Override
-    public void setIdBase(String value) {
-    }
-
-    public Base[] getProperty(int hash, String name, boolean checkValid) throws FHIRException {
-      if (name.equals("name")) {
-        return new Base[] { new StringType(getName()) };
-      } else if (name.equals("namespace")) {
-        return new Base[] { new StringType(getNamespace()) };
-      } else {
-        return super.getProperty(hash, name, checkValid);
-      }
-    }
-
-    private String getNamespace() {
-      if ((instance instanceof Resource)) {
-        return "FHIR";
-      } else if (!(instance instanceof Element) || ((Element) instance).isDisallowExtensions()) {
-        return "System";
-      } else {
-        return "FHIR";
-      }
-    }
-
-    private String getName() {
-      if ((instance instanceof Resource)) {
-        return instance.fhirType();
-      } else if (!(instance instanceof Element) || ((Element) instance).isDisallowExtensions()) {
-        return Utilities.capitalize(instance.fhirType());
-      } else {
-        return instance.fhirType();
-      }
-    }
-
-    @Override
-    public Base copy() {
-      throw new Error("Not Implemented");
-    }
-
-  }
-
-  public static class TypedElementDefinition {
-    private ElementDefinition element;
-    private String type;
-    private StructureDefinition src;
-
-    public TypedElementDefinition(StructureDefinition src, ElementDefinition element, String type) {
-      super();
-      this.element = element;
-      this.type = type;
-      this.src = src;
-    }
-
-    public TypedElementDefinition(ElementDefinition element) {
-      super();
-      this.element = element;
-    }
-
-    public ElementDefinition getElement() {
-      return element;
-    }
-
-    public String getType() {
-      return type;
-    }
-
-    public List<TypeRefComponent> getTypes() {
-      List<TypeRefComponent> res = new ArrayList<ElementDefinition.TypeRefComponent>();
-      for (TypeRefComponent tr : element.getType()) {
-        if (type == null || type.equals(tr.getCode())) {
-          res.add(tr);
-        }
-      }
-      return res;
-    }
-
-    public boolean hasType(String tn) {
-      if (type != null) {
-        return tn.equals(type);
-      } else {
-        for (TypeRefComponent t : element.getType()) {
-          if (tn.equals(t.getCode())) {
-            return true;
-          }
-        }
-        return false;
-      }
-    }
-
-    public StructureDefinition getSrc() {
-      return src;
-    }
-  }
-
   private IWorkerContext worker;
   private IEvaluationContext hostServices;
   private StringBuilder log = new StringBuilder();
@@ -292,31 +134,7 @@ public class FHIRPathEngine {
   // defined in the specification
   // the application can implement them by providing a constant resolver
   public interface IEvaluationContext {
-    public class FunctionDetails {
+   
-      private String description;
-      private int minParameters;
-      private int maxParameters;
-
-      public FunctionDetails(String description, int minParameters, int maxParameters) {
-        super();
-        this.description = description;
-        this.minParameters = minParameters;
-        this.maxParameters = maxParameters;
-      }
-
-      public String getDescription() {
-        return description;
-      }
-
-      public int getMinParameters() {
-        return minParameters;
-      }
-
-      public int getMaxParameters() {
-        return maxParameters;
-      }
-
-    }
 
     /**
      * A constant reference - e.g. a reference to a name that must be resolved in
@@ -6129,7 +5947,7 @@ public class FHIRPathEngine {
     return result;
   }
 
-  public class ElementDefinitionMatch {
+  private class ElementDefinitionMatch {
     private ElementDefinition definition;
     private String fixedType;
 

org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/utils/FHIRPathUtilityClasses.java

@@ -0,0 +1,210 @@
+package org.hl7.fhir.r4.utils;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.hl7.fhir.exceptions.FHIRException;
+import org.hl7.fhir.r4.model.Base;
+import org.hl7.fhir.r4.model.Element;
+import org.hl7.fhir.r4.model.ElementDefinition;
+import org.hl7.fhir.r4.model.IntegerType;
+import org.hl7.fhir.r4.model.Property;
+import org.hl7.fhir.r4.model.Resource;
+import org.hl7.fhir.r4.model.StringType;
+import org.hl7.fhir.r4.model.StructureDefinition;
+import org.hl7.fhir.r4.model.TypeDetails;
+import org.hl7.fhir.r4.model.ElementDefinition.TypeRefComponent;
+import org.hl7.fhir.utilities.Utilities;
+import org.hl7.fhir.utilities.i18n.I18nConstants;
+
+public class FHIRPathUtilityClasses {
+
+
+  public static class FHIRConstant extends Base {
+
+    private static final long serialVersionUID = -8933773658248269439L;
+    private String value;
+
+    public FHIRConstant(String value) {
+      this.value = value;
+    }
+
+    @Override
+    public String fhirType() {
+      return "%constant";
+    }
+
+    @Override
+    protected void listChildren(List<Property> result) {
+    }
+
+    @Override
+    public String getIdBase() {
+      return null;
+    }
+
+    @Override
+    public void setIdBase(String value) {
+    }
+
+    public String getValue() {
+      return value;
+    }
+
+    @Override
+    public String primitiveValue() {
+      return value;
+    }
+
+    @Override
+    public Base copy() {
+      throw new Error("Not Implemented");
+    }
+
+  }
+
+  public static class ClassTypeInfo extends Base {
+    private static final long serialVersionUID = 4909223114071029317L;
+    private Base instance;
+
+    public ClassTypeInfo(Base instance) {
+      super();
+      this.instance = instance;
+    }
+
+    @Override
+    public String fhirType() {
+      return "ClassInfo";
+    }
+
+    @Override
+    protected void listChildren(List<Property> result) {
+    }
+
+    @Override
+    public String getIdBase() {
+      return null;
+    }
+
+    @Override
+    public void setIdBase(String value) {
+    }
+
+    public Base[] getProperty(int hash, String name, boolean checkValid) throws FHIRException {
+      if (name.equals("name")) {
+        return new Base[] { new StringType(getName()) };
+      } else if (name.equals("namespace")) {
+        return new Base[] { new StringType(getNamespace()) };
+      } else {
+        return super.getProperty(hash, name, checkValid);
+      }
+    }
+
+    private String getNamespace() {
+      if ((instance instanceof Resource)) {
+        return "FHIR";
+      } else if (!(instance instanceof Element) || ((Element) instance).isDisallowExtensions()) {
+        return "System";
+      } else {
+        return "FHIR";
+      }
+    }
+
+    private String getName() {
+      if ((instance instanceof Resource)) {
+        return instance.fhirType();
+      } else if (!(instance instanceof Element) || ((Element) instance).isDisallowExtensions()) {
+        return Utilities.capitalize(instance.fhirType());
+      } else {
+        return instance.fhirType();
+      }
+    }
+
+    @Override
+    public Base copy() {
+      throw new Error("Not Implemented");
+    }
+
+  }
+
+  public static class TypedElementDefinition {
+    private ElementDefinition element;
+    private String type;
+    private StructureDefinition src;
+
+    public TypedElementDefinition(StructureDefinition src, ElementDefinition element, String type) {
+      super();
+      this.element = element;
+      this.type = type;
+      this.src = src;
+    }
+
+    public TypedElementDefinition(ElementDefinition element) {
+      super();
+      this.element = element;
+    }
+
+    public ElementDefinition getElement() {
+      return element;
+    }
+
+    public String getType() {
+      return type;
+    }
+
+    public List<TypeRefComponent> getTypes() {
+      List<TypeRefComponent> res = new ArrayList<ElementDefinition.TypeRefComponent>();
+      for (TypeRefComponent tr : element.getType()) {
+        if (type == null || type.equals(tr.getCode())) {
+          res.add(tr);
+        }
+      }
+      return res;
+    }
+
+    public boolean hasType(String tn) {
+      if (type != null) {
+        return tn.equals(type);
+      } else {
+        for (TypeRefComponent t : element.getType()) {
+          if (tn.equals(t.getCode())) {
+            return true;
+          }
+        }
+        return false;
+      }
+    }
+
+    public StructureDefinition getSrc() {
+      return src;
+    }
+  }
+
+  public static class FunctionDetails {
+    private String description;
+    private int minParameters;
+    private int maxParameters;
+
+    public FunctionDetails(String description, int minParameters, int maxParameters) {
+      super();
+      this.description = description;
+      this.minParameters = minParameters;
+      this.maxParameters = maxParameters;
+    }
+
+    public String getDescription() {
+      return description;
+    }
+
+    public int getMinParameters() {
+      return minParameters;
+    }
+
+    public int getMaxParameters() {
+      return maxParameters;
+    }
+
+  }
+}

org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/utils/LiquidEngine.java

@@ -46,6 +46,7 @@ import org.hl7.fhir.r4.model.TypeDetails;
 import org.hl7.fhir.r4.model.ValueSet;
 import org.hl7.fhir.r4.utils.FHIRPathEngine.ExpressionNodeWithOffset;
 import org.hl7.fhir.r4.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r4.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.utilities.Utilities;
 
 public class LiquidEngine implements IEvaluationContext {

org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/utils/StructureMapUtilities.java

@@ -114,6 +114,7 @@ import org.hl7.fhir.r4.model.ValueSet.ValueSetExpansionContainsComponent;
 import org.hl7.fhir.r4.terminologies.ValueSetExpander.ValueSetExpansionOutcome;
 import org.hl7.fhir.r4.utils.FHIRLexer.FHIRLexerException;
 import org.hl7.fhir.r4.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r4.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.r4.utils.validation.IResourceValidator;
 import org.hl7.fhir.utilities.CommaSeparatedStringBuilder;
 import org.hl7.fhir.utilities.TerminologyServiceOptions;

org.hl7.fhir.r4/src/test/java/org/hl7/fhir/r4/test/FHIRPathTests.java

@@ -34,6 +34,7 @@ import org.hl7.fhir.r4.model.ValueSet;
 import org.hl7.fhir.r4.test.utils.TestingUtilities;
 import org.hl7.fhir.r4.utils.FHIRPathEngine;
 import org.hl7.fhir.r4.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r4.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.utilities.Utilities;
 import org.hl7.fhir.utilities.xml.XMLUtil;
 import org.junit.jupiter.api.Assertions;

org.hl7.fhir.r4/src/test/java/org/hl7/fhir/r4/test/SnapShotGenerationTests.java

@@ -33,6 +33,7 @@ import org.hl7.fhir.r4.model.ValueSet;
 import org.hl7.fhir.r4.test.utils.TestingUtilities;
 import org.hl7.fhir.r4.utils.FHIRPathEngine;
 import org.hl7.fhir.r4.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r4.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.r4.utils.NarrativeGenerator;
 import org.hl7.fhir.r4.utils.validation.IResourceValidator;
 import org.hl7.fhir.utilities.Utilities;

org.hl7.fhir.r4b/src/main/java/org/hl7/fhir/r4b/comparison/ComparisonRenderer.java

@@ -31,6 +31,7 @@ import org.hl7.fhir.r4b.model.Tuple;
 import org.hl7.fhir.r4b.model.TypeDetails;
 import org.hl7.fhir.r4b.model.ValueSet;
 import org.hl7.fhir.r4b.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r4b.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.r4b.utils.LiquidEngine;
 import org.hl7.fhir.r4b.utils.LiquidEngine.LiquidDocument;
 import org.hl7.fhir.utilities.TextFile;

org.hl7.fhir.r4b/src/main/java/org/hl7/fhir/r4b/utils/FHIRPathEngine.java

@@ -57,7 +57,10 @@ import org.hl7.fhir.r4b.model.TypeDetails;
 import org.hl7.fhir.r4b.model.TypeDetails.ProfiledType;
 import org.hl7.fhir.r4b.model.ValueSet;
 import org.hl7.fhir.r4b.utils.FHIRLexer.FHIRLexerException;
-import org.hl7.fhir.r4b.utils.FHIRPathEngine.IEvaluationContext.FunctionDetails;
+import org.hl7.fhir.r4b.utils.FHIRPathUtilityClasses.FHIRConstant;
+import org.hl7.fhir.r4b.utils.FHIRPathUtilityClasses.ClassTypeInfo;
+import org.hl7.fhir.r4b.utils.FHIRPathUtilityClasses.TypedElementDefinition;
+import org.hl7.fhir.r4b.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.utilities.CommaSeparatedStringBuilder;
 import org.hl7.fhir.utilities.MergedList;
 import org.hl7.fhir.utilities.MergedList.MergeNode;
@@ -112,160 +115,6 @@ public class FHIRPathEngine {
     Null, True, False
   }
 
-  private class FHIRConstant extends Base {
-
-    private static final long serialVersionUID = -8933773658248269439L;
-    private String value;
-
-    public FHIRConstant(String value) {
-      this.value = value;
-    }
-
-    @Override
-    public String fhirType() {
-      return "%constant";
-    }
-
-    @Override
-    protected void listChildren(List<Property> result) {
-    }
-
-    @Override
-    public String getIdBase() {
-      return null;
-    }
-
-    @Override
-    public void setIdBase(String value) {
-    }
-
-    public String getValue() {
-      return value;
-    }
-
-    @Override
-    public String primitiveValue() {
-      return value;
-    }
-
-    @Override
-    public Base copy() {
-      throw new Error("Not Implemented");
-    }
-  }
-
-  private class ClassTypeInfo extends Base {
-    private static final long serialVersionUID = 4909223114071029317L;
-    private Base instance;
-
-    public ClassTypeInfo(Base instance) {
-      super();
-      this.instance = instance;
-    }
-
-    @Override
-    public String fhirType() {
-      return "ClassInfo";
-    }
-
-    @Override
-    protected void listChildren(List<Property> result) {
-    }
-
-    @Override
-    public String getIdBase() {
-      return null;
-    }
-
-    @Override
-    public void setIdBase(String value) {
-    }
-
-    public Base[] getProperty(int hash, String name, boolean checkValid) throws FHIRException {
-      if (name.equals("name")) {
-        return new Base[] { new StringType(getName()) };
-      } else if (name.equals("namespace")) {
-        return new Base[] { new StringType(getNamespace()) };
-      } else {
-        return super.getProperty(hash, name, checkValid);
-      }
-    }
-
-    private String getNamespace() {
-      if ((instance instanceof Resource)) {
-        return "FHIR";
-      } else if (!(instance instanceof Element) || ((Element) instance).isDisallowExtensions()) {
-        return "System";
-      } else {
-        return "FHIR";
-      }
-    }
-
-    private String getName() {
-      if ((instance instanceof Resource)) {
-        return instance.fhirType();
-      } else if (!(instance instanceof Element) || ((Element) instance).isDisallowExtensions()) {
-        return Utilities.capitalize(instance.fhirType());
-      } else {
-        return instance.fhirType();
-      }
-    }
-
-    @Override
-    public Base copy() {
-      throw new Error("Not Implemented");
-    }
-
-  }
-
-  public static class TypedElementDefinition {
-    private ElementDefinition element;
-    private String type;
-
-    public TypedElementDefinition(ElementDefinition element, String type) {
-      super();
-      this.element = element;
-      this.type = type;
-    }
-
-    public TypedElementDefinition(ElementDefinition element) {
-      super();
-      this.element = element;
-    }
-
-    public ElementDefinition getElement() {
-      return element;
-    }
-
-    public String getType() {
-      return type;
-    }
-
-    public List<TypeRefComponent> getTypes() {
-      List<TypeRefComponent> res = new ArrayList<ElementDefinition.TypeRefComponent>();
-      for (TypeRefComponent tr : element.getType()) {
-        if (type == null || type.equals(tr.getCode())) {
-          res.add(tr);
-        }
-      }
-      return res;
-    }
-
-    public boolean hasType(String tn) {
-      if (type != null) {
-        return tn.equals(type);
-      } else {
-        for (TypeRefComponent t : element.getType()) {
-          if (tn.equals(t.getCode())) {
-            return true;
-          }
-        }
-        return false;
-      }
-    }
-
-  }
-
   private IWorkerContext worker;
   private IEvaluationContext hostServices;
   private StringBuilder log = new StringBuilder();
@@ -288,32 +137,7 @@ public class FHIRPathEngine {
   // defined in the specification
   // the application can implement them by providing a constant resolver
   public interface IEvaluationContext {
-    public class FunctionDetails {
+    
-      private String description;
-      private int minParameters;
-      private int maxParameters;
-
-      public FunctionDetails(String description, int minParameters, int maxParameters) {
-        super();
-        this.description = description;
-        this.minParameters = minParameters;
-        this.maxParameters = maxParameters;
-      }
-
-      public String getDescription() {
-        return description;
-      }
-
-      public int getMinParameters() {
-        return minParameters;
-      }
-
-      public int getMaxParameters() {
-        return maxParameters;
-      }
-
-    }
-
     /**
      * A constant reference - e.g. a reference to a name that must be resolved in
      * context. The % will be removed from the constant name before this is invoked.
@@ -6126,7 +5950,7 @@ public class FHIRPathEngine {
     return result;
   }
 
-  public class ElementDefinitionMatch {
+  private class ElementDefinitionMatch {
     private ElementDefinition definition;
     private String fixedType;
 

org.hl7.fhir.r4b/src/main/java/org/hl7/fhir/r4b/utils/FHIRPathUtilityClasses.java

@@ -0,0 +1,198 @@
+package org.hl7.fhir.r4b.utils;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.hl7.fhir.exceptions.FHIRException;
+import org.hl7.fhir.r4b.model.Base;
+import org.hl7.fhir.r4b.model.Element;
+import org.hl7.fhir.r4b.model.ElementDefinition;
+import org.hl7.fhir.r4b.model.Property;
+import org.hl7.fhir.r4b.model.Resource;
+import org.hl7.fhir.r4b.model.StringType;
+import org.hl7.fhir.r4b.model.ElementDefinition.TypeRefComponent;
+import org.hl7.fhir.utilities.Utilities;
+
+public class FHIRPathUtilityClasses {
+
+  public static class FHIRConstant extends Base {
+
+    private static final long serialVersionUID = -8933773658248269439L;
+    private String value;
+
+    public FHIRConstant(String value) {
+      this.value = value;
+    }
+
+    @Override
+    public String fhirType() {
+      return "%constant";
+    }
+
+    @Override
+    protected void listChildren(List<Property> result) {
+    }
+
+    @Override
+    public String getIdBase() {
+      return null;
+    }
+
+    @Override
+    public void setIdBase(String value) {
+    }
+
+    public String getValue() {
+      return value;
+    }
+
+    @Override
+    public String primitiveValue() {
+      return value;
+    }
+
+    @Override
+    public Base copy() {
+      throw new Error("Not Implemented");
+    }
+  }
+
+  public static class ClassTypeInfo extends Base {
+    private static final long serialVersionUID = 4909223114071029317L;
+    private Base instance;
+
+    public ClassTypeInfo(Base instance) {
+      super();
+      this.instance = instance;
+    }
+
+    @Override
+    public String fhirType() {
+      return "ClassInfo";
+    }
+
+    @Override
+    protected void listChildren(List<Property> result) {
+    }
+
+    @Override
+    public String getIdBase() {
+      return null;
+    }
+
+    @Override
+    public void setIdBase(String value) {
+    }
+
+    public Base[] getProperty(int hash, String name, boolean checkValid) throws FHIRException {
+      if (name.equals("name")) {
+        return new Base[] { new StringType(getName()) };
+      } else if (name.equals("namespace")) {
+        return new Base[] { new StringType(getNamespace()) };
+      } else {
+        return super.getProperty(hash, name, checkValid);
+      }
+    }
+
+    private String getNamespace() {
+      if ((instance instanceof Resource)) {
+        return "FHIR";
+      } else if (!(instance instanceof Element) || ((Element) instance).isDisallowExtensions()) {
+        return "System";
+      } else {
+        return "FHIR";
+      }
+    }
+
+    private String getName() {
+      if ((instance instanceof Resource)) {
+        return instance.fhirType();
+      } else if (!(instance instanceof Element) || ((Element) instance).isDisallowExtensions()) {
+        return Utilities.capitalize(instance.fhirType());
+      } else {
+        return instance.fhirType();
+      }
+    }
+
+    @Override
+    public Base copy() {
+      throw new Error("Not Implemented");
+    }
+
+  }
+
+  public static class TypedElementDefinition {
+    private ElementDefinition element;
+    private String type;
+
+    public TypedElementDefinition(ElementDefinition element, String type) {
+      super();
+      this.element = element;
+      this.type = type;
+    }
+
+    public TypedElementDefinition(ElementDefinition element) {
+      super();
+      this.element = element;
+    }
+
+    public ElementDefinition getElement() {
+      return element;
+    }
+
+    public String getType() {
+      return type;
+    }
+
+    public List<TypeRefComponent> getTypes() {
+      List<TypeRefComponent> res = new ArrayList<ElementDefinition.TypeRefComponent>();
+      for (TypeRefComponent tr : element.getType()) {
+        if (type == null || type.equals(tr.getCode())) {
+          res.add(tr);
+        }
+      }
+      return res;
+    }
+
+    public boolean hasType(String tn) {
+      if (type != null) {
+        return tn.equals(type);
+      } else {
+        for (TypeRefComponent t : element.getType()) {
+          if (tn.equals(t.getCode())) {
+            return true;
+          }
+        }
+        return false;
+      }
+    }
+
+  }
+  
+  public static class FunctionDetails {
+    private String description;
+    private int minParameters;
+    private int maxParameters;
+
+    public FunctionDetails(String description, int minParameters, int maxParameters) {
+      super();
+      this.description = description;
+      this.minParameters = minParameters;
+      this.maxParameters = maxParameters;
+    }
+
+    public String getDescription() {
+      return description;
+    }
+
+    public int getMinParameters() {
+      return minParameters;
+    }
+
+    public int getMaxParameters() {
+      return maxParameters;
+    }
+
+  }
+
+}

org.hl7.fhir.r4b/src/main/java/org/hl7/fhir/r4b/utils/LiquidEngine.java

@@ -49,6 +49,7 @@ import org.hl7.fhir.r4b.model.TypeDetails;
 import org.hl7.fhir.r4b.model.ValueSet;
 import org.hl7.fhir.r4b.utils.FHIRPathEngine.ExpressionNodeWithOffset;
 import org.hl7.fhir.r4b.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r4b.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.utilities.Utilities;
 import org.hl7.fhir.utilities.i18n.I18nConstants;
 import org.hl7.fhir.utilities.xhtml.NodeType;

org.hl7.fhir.r4b/src/main/java/org/hl7/fhir/r4b/utils/structuremap/FFHIRPathHostServices.java

@@ -9,6 +9,7 @@ import org.hl7.fhir.r4b.model.Resource;
 import org.hl7.fhir.r4b.model.TypeDetails;
 import org.hl7.fhir.r4b.model.ValueSet;
 import org.hl7.fhir.r4b.utils.FHIRPathEngine;
+import org.hl7.fhir.r4b.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.r4b.utils.validation.IResourceValidator;
 import org.hl7.fhir.utilities.validation.ValidationMessage;
 

org.hl7.fhir.r4b/src/main/java/org/hl7/fhir/r4b/utils/structuremap/StructureMapUtilities.java

@@ -68,6 +68,7 @@ import org.hl7.fhir.r4b.utils.FHIRLexer;
 import org.hl7.fhir.r4b.utils.FHIRLexer.FHIRLexerException;
 import org.hl7.fhir.r4b.utils.FHIRPathEngine;
 import org.hl7.fhir.r4b.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r4b.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.r4b.utils.ToolingExtensions;
 import org.hl7.fhir.r4b.utils.validation.IResourceValidator;
 import org.hl7.fhir.utilities.CommaSeparatedStringBuilder;

org.hl7.fhir.r4b/src/test/java/org/hl7/fhir/r4b/test/FHIRPathTests.java

@@ -18,6 +18,7 @@ import org.hl7.fhir.r4b.test.FHIRPathTests.TestResultType;
 import org.hl7.fhir.r4b.test.utils.TestingUtilities;
 import org.hl7.fhir.r4b.utils.FHIRPathEngine;
 import org.hl7.fhir.r4b.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r4b.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.utilities.Utilities;
 import org.hl7.fhir.utilities.xml.XMLUtil;
 import org.junit.jupiter.api.Assertions;

org.hl7.fhir.r4b/src/test/java/org/hl7/fhir/r4b/test/SnapShotGenerationTests.java

@@ -39,6 +39,7 @@ import org.hl7.fhir.r4b.model.ValueSet;
 import org.hl7.fhir.r4b.test.utils.TestingUtilities;
 import org.hl7.fhir.r4b.utils.FHIRPathEngine;
 import org.hl7.fhir.r4b.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r4b.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.r4b.utils.validation.IResourceValidator;
 import org.hl7.fhir.r4b.utils.XVerExtensionManager;
 import org.hl7.fhir.utilities.Utilities;

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/comparison/ComparisonRenderer.java

@@ -30,6 +30,7 @@ import org.hl7.fhir.r5.model.Tuple;
 import org.hl7.fhir.r5.model.TypeDetails;
 import org.hl7.fhir.r5.model.ValueSet;
 import org.hl7.fhir.r5.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.r5.utils.LiquidEngine;
 import org.hl7.fhir.r5.utils.LiquidEngine.LiquidDocument;
 import org.hl7.fhir.utilities.TextFile;

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/FHIRPathEngine.java

@@ -61,7 +61,10 @@ import org.hl7.fhir.r5.model.TypeDetails;
 import org.hl7.fhir.r5.model.TypeDetails.ProfiledType;
 import org.hl7.fhir.r5.model.ValueSet;
 import org.hl7.fhir.r5.utils.FHIRLexer.FHIRLexerException;
-import org.hl7.fhir.r5.utils.FHIRPathEngine.IEvaluationContext.FunctionDetails;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.FHIRConstant;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.ClassTypeInfo;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.FunctionDetails;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.TypedElementDefinition;
 import org.hl7.fhir.utilities.CommaSeparatedStringBuilder;
 import org.hl7.fhir.utilities.MarkDownProcessor;
 import org.hl7.fhir.utilities.MergedList;
@@ -115,157 +118,7 @@ import ca.uhn.fhir.util.ElementUtil;
 public class FHIRPathEngine {
 
   private enum Equality { Null, True, False }
-
+  
-  private class FHIRConstant extends Base {
-
-    private static final long serialVersionUID = -8933773658248269439L;
-    private String value;
-
-    public FHIRConstant(String value) {
-      this.value = value;
-    }
-
-    @Override    
-    public String fhirType() {
-      return "%constant";
-    }
-
-    @Override
-    protected void listChildren(List<Property> result) {
-    }
-
-    @Override
-    public String getIdBase() {
-      return null;
-    }
-
-    @Override
-    public void setIdBase(String value) {
-    }
-
-    public String getValue() {
-      return value;
-    }
-
-    @Override
-    public String primitiveValue() {
-      return value;
-    }
-
-    @Override
-    public Base copy() {
-      throw new Error("Not Implemented");
-    }
-  }
-
-  private class ClassTypeInfo extends Base {
-    private static final long serialVersionUID = 4909223114071029317L;
-    private Base instance;
-
-    public ClassTypeInfo(Base instance) {
-      super();
-      this.instance = instance;
-    }
-
-    @Override
-    public String fhirType() {
-      return "ClassInfo";
-    }
-
-    @Override
-    protected void listChildren(List<Property> result) {
-    }
-
-    @Override
-    public String getIdBase() {
-      return null;
-    }
-
-    @Override
-    public void setIdBase(String value) {
-    }
-
-    public Base[] getProperty(int hash, String name, boolean checkValid) throws FHIRException {
-      if (name.equals("name")) {
-        return new Base[]{new StringType(getName())};
-      } else if (name.equals("namespace")) { 
-        return new Base[]{new StringType(getNamespace())};
-      } else {
-        return super.getProperty(hash, name, checkValid);
-      }
-    }
-
-    private String getNamespace() {
-      if ((instance instanceof Resource)) {
-        return "FHIR";
-      } else if (!(instance instanceof Element) || ((Element)instance).isDisallowExtensions()) {
-        return "System";
-      } else {
-        return "FHIR";
-      }
-    }
-
-    private String getName() {
-      if ((instance instanceof Resource)) {
-        return instance.fhirType();
-      } else if (!(instance instanceof Element) || ((Element)instance).isDisallowExtensions()) {
-        return Utilities.capitalize(instance.fhirType());
-      } else {
-        return instance.fhirType();
-      }
-    }
-
-    @Override
-    public Base copy() {
-      throw new Error("Not Implemented");
-    }
-  }
-
-  public static class TypedElementDefinition {
-    private ElementDefinition element;
-    private String type;
-    private StructureDefinition src;
-    public TypedElementDefinition(StructureDefinition src, ElementDefinition element, String type) {
-      super();
-      this.element = element;
-      this.type = type;
-      this.src = src;
-    }
-    public TypedElementDefinition(ElementDefinition element) {
-      super();
-      this.element = element;
-    }
-    public ElementDefinition getElement() {
-      return element;
-    }
-    public String getType() {
-      return type;
-    }
-    public List<TypeRefComponent> getTypes() {
-      List<TypeRefComponent> res = new ArrayList<ElementDefinition.TypeRefComponent>();
-      for (TypeRefComponent tr : element.getType()) {
-        if (type == null || type.equals(tr.getCode())) {
-          res.add(tr);
-        }
-      }
-      return res;
-    }
-    public boolean hasType(String tn) {
-      if (type != null) {
-        return tn.equals(type);
-      } else {
-        for (TypeRefComponent t : element.getType()) {
-          if (tn.equals(t.getCode())) {
-            return true;
-          }
-        }
-        return false;
-      }
-    }
-    public StructureDefinition getSrc() {
-      return src;
-    }
-  }
   private IWorkerContext worker;
   private IEvaluationContext hostServices;
   private StringBuilder log = new StringBuilder();
@@ -286,27 +139,6 @@ public class FHIRPathEngine {
   // if the fhir path expressions are allowed to use constants beyond those defined in the specification
   // the application can implement them by providing a constant resolver 
   public interface IEvaluationContext {
-    public class FunctionDetails {
-      private String description;
-      private int minParameters;
-      private int maxParameters;
-      public FunctionDetails(String description, int minParameters, int maxParameters) {
-        super();
-        this.description = description;
-        this.minParameters = minParameters;
-        this.maxParameters = maxParameters;
-      }
-      public String getDescription() {
-        return description;
-      }
-      public int getMinParameters() {
-        return minParameters;
-      }
-      public int getMaxParameters() {
-        return maxParameters;
-      }
-
-    }
 
     /**
      * A constant reference - e.g. a reference to a name that must be resolved in context.
@@ -5909,7 +5741,7 @@ public class FHIRPathEngine {
     return result;
   }
 
-  public class ElementDefinitionMatch {
+  private class ElementDefinitionMatch {
     private ElementDefinition definition;
     private ElementDefinition sourceDefinition; // if there was a content reference
     private String fixedType;

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/FHIRPathUtilityClasses.java

@@ -0,0 +1,192 @@
+package org.hl7.fhir.r5.utils;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.hl7.fhir.exceptions.FHIRException;
+import org.hl7.fhir.r5.model.Base;
+import org.hl7.fhir.r5.model.Element;
+import org.hl7.fhir.r5.model.ElementDefinition;
+import org.hl7.fhir.r5.model.Property;
+import org.hl7.fhir.r5.model.Resource;
+import org.hl7.fhir.r5.model.StringType;
+import org.hl7.fhir.r5.model.StructureDefinition;
+import org.hl7.fhir.r5.model.ElementDefinition.TypeRefComponent;
+import org.hl7.fhir.utilities.Utilities;
+
+public class FHIRPathUtilityClasses {
+
+  public static class FHIRConstant extends Base {
+
+    private static final long serialVersionUID = -8933773658248269439L;
+    private String value;
+
+    public FHIRConstant(String value) {
+      this.value = value;
+    }
+
+    @Override    
+    public String fhirType() {
+      return "%constant";
+    }
+
+    @Override
+    protected void listChildren(List<Property> result) {
+    }
+
+    @Override
+    public String getIdBase() {
+      return null;
+    }
+
+    @Override
+    public void setIdBase(String value) {
+    }
+
+    public String getValue() {
+      return value;
+    }
+
+    @Override
+    public String primitiveValue() {
+      return value;
+    }
+
+    @Override
+    public Base copy() {
+      throw new Error("Not Implemented");
+    }
+  }
+
+  public static class ClassTypeInfo extends Base {
+    private static final long serialVersionUID = 4909223114071029317L;
+    private Base instance;
+
+    public ClassTypeInfo(Base instance) {
+      super();
+      this.instance = instance;
+    }
+
+    @Override
+    public String fhirType() {
+      return "ClassInfo";
+    }
+
+    @Override
+    protected void listChildren(List<Property> result) {
+    }
+
+    @Override
+    public String getIdBase() {
+      return null;
+    }
+
+    @Override
+    public void setIdBase(String value) {
+    }
+
+    public Base[] getProperty(int hash, String name, boolean checkValid) throws FHIRException {
+      if (name.equals("name")) {
+        return new Base[]{new StringType(getName())};
+      } else if (name.equals("namespace")) { 
+        return new Base[]{new StringType(getNamespace())};
+      } else {
+        return super.getProperty(hash, name, checkValid);
+      }
+    }
+
+    private String getNamespace() {
+      if ((instance instanceof Resource)) {
+        return "FHIR";
+      } else if (!(instance instanceof Element) || ((Element)instance).isDisallowExtensions()) {
+        return "System";
+      } else {
+        return "FHIR";
+      }
+    }
+
+    private String getName() {
+      if ((instance instanceof Resource)) {
+        return instance.fhirType();
+      } else if (!(instance instanceof Element) || ((Element)instance).isDisallowExtensions()) {
+        return Utilities.capitalize(instance.fhirType());
+      } else {
+        return instance.fhirType();
+      }
+    }
+
+    @Override
+    public Base copy() {
+      throw new Error("Not Implemented");
+    }
+  }
+
+  public static class TypedElementDefinition {
+    private ElementDefinition element;
+    private String type;
+    private StructureDefinition src;
+    public TypedElementDefinition(StructureDefinition src, ElementDefinition element, String type) {
+      super();
+      this.element = element;
+      this.type = type;
+      this.src = src;
+    }
+    public TypedElementDefinition(ElementDefinition element) {
+      super();
+      this.element = element;
+    }
+    public ElementDefinition getElement() {
+      return element;
+    }
+    public String getType() {
+      return type;
+    }
+    public List<TypeRefComponent> getTypes() {
+      List<TypeRefComponent> res = new ArrayList<ElementDefinition.TypeRefComponent>();
+      for (TypeRefComponent tr : element.getType()) {
+        if (type == null || type.equals(tr.getCode())) {
+          res.add(tr);
+        }
+      }
+      return res;
+    }
+    public boolean hasType(String tn) {
+      if (type != null) {
+        return tn.equals(type);
+      } else {
+        for (TypeRefComponent t : element.getType()) {
+          if (tn.equals(t.getCode())) {
+            return true;
+          }
+        }
+        return false;
+      }
+    }
+    public StructureDefinition getSrc() {
+      return src;
+    }
+  }
+  
+
+  public static class FunctionDetails {
+    private String description;
+    private int minParameters;
+    private int maxParameters;
+    public FunctionDetails(String description, int minParameters, int maxParameters) {
+      super();
+      this.description = description;
+      this.minParameters = minParameters;
+      this.maxParameters = maxParameters;
+    }
+    public String getDescription() {
+      return description;
+    }
+    public int getMinParameters() {
+      return minParameters;
+    }
+    public int getMaxParameters() {
+      return maxParameters;
+    }
+
+  }
+}

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/LiquidEngine.java

@@ -46,6 +46,7 @@ import org.hl7.fhir.r5.model.TypeDetails;
 import org.hl7.fhir.r5.model.ValueSet;
 import org.hl7.fhir.r5.utils.FHIRPathEngine.ExpressionNodeWithOffset;
 import org.hl7.fhir.r5.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.utilities.Utilities;
 import org.hl7.fhir.utilities.i18n.I18nConstants;
 import org.hl7.fhir.utilities.xhtml.NodeType;

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/structuremap/FFHIRPathHostServices.java

@@ -9,6 +9,7 @@ import org.hl7.fhir.r5.model.Resource;
 import org.hl7.fhir.r5.model.TypeDetails;
 import org.hl7.fhir.r5.model.ValueSet;
 import org.hl7.fhir.r5.utils.FHIRPathEngine;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.r5.utils.validation.IResourceValidator;
 import org.hl7.fhir.utilities.validation.ValidationMessage;
 

org.hl7.fhir.r5/src/test/java/org/hl7/fhir/r5/test/FHIRPathTests.java

@@ -20,6 +20,7 @@ import org.hl7.fhir.r5.model.*;
 import org.hl7.fhir.r5.test.utils.TestingUtilities;
 import org.hl7.fhir.r5.utils.FHIRPathEngine;
 import org.hl7.fhir.r5.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.utilities.Utilities;
 import org.hl7.fhir.utilities.xml.XMLUtil;
 import org.junit.jupiter.api.Assertions;

org.hl7.fhir.r5/src/test/java/org/hl7/fhir/r5/test/SnapShotGenerationTests.java

@@ -40,6 +40,7 @@ import org.hl7.fhir.r5.renderers.utils.RenderingContext.ResourceRendererMode;
 import org.hl7.fhir.r5.test.utils.TestingUtilities;
 import org.hl7.fhir.r5.utils.FHIRPathEngine;
 import org.hl7.fhir.r5.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.r5.utils.XVerExtensionManager;
 import org.hl7.fhir.r5.utils.validation.IResourceValidator;
 import org.hl7.fhir.utilities.Utilities;

org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/InstanceValidator.java

@@ -155,7 +155,8 @@ import org.hl7.fhir.r5.utils.BuildExtensions;
 import org.hl7.fhir.r5.utils.FHIRLexer.FHIRLexerException;
 import org.hl7.fhir.r5.utils.FHIRPathEngine;
 import org.hl7.fhir.r5.utils.FHIRPathEngine.IEvaluationContext;
-import org.hl7.fhir.r5.utils.FHIRPathEngine.TypedElementDefinition;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.FunctionDetails;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.TypedElementDefinition;
 import org.hl7.fhir.r5.utils.ResourceUtilities;
 import org.hl7.fhir.r5.utils.ToolingExtensions;
 import org.hl7.fhir.r5.utils.XVerExtensionManager;

org.hl7.fhir.validation/src/test/java/org/hl7/fhir/conversion/tests/SnapShotGenerationXTests.java

@@ -37,6 +37,7 @@ import org.hl7.fhir.r5.renderers.utils.RenderingContext.ResourceRendererMode;
 import org.hl7.fhir.r5.test.utils.TestingUtilities;
 import org.hl7.fhir.r5.utils.FHIRPathEngine;
 import org.hl7.fhir.r5.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.r5.utils.validation.IResourceValidator;
 import org.hl7.fhir.utilities.Utilities;
 import org.hl7.fhir.utilities.validation.ValidationMessage;

org.hl7.fhir.validation/src/test/java/org/hl7/fhir/validation/tests/ValidationTests.java

@@ -52,6 +52,7 @@ import org.hl7.fhir.r5.model.ValueSet;
 import org.hl7.fhir.r5.test.utils.TestingUtilities;
 import org.hl7.fhir.r5.utils.FHIRPathEngine;
 import org.hl7.fhir.r5.utils.FHIRPathEngine.IEvaluationContext;
+import org.hl7.fhir.r5.utils.FHIRPathUtilityClasses.FunctionDetails;
 import org.hl7.fhir.r5.utils.OperationOutcomeUtilities;
 import org.hl7.fhir.r5.utils.validation.BundleValidationRule;
 import org.hl7.fhir.r5.utils.validation.IResourceValidator;