diff --git a/Snippets/use-program-instanceswithtypes.swift b/Snippets/use-program-instanceswithtypes.swift
index a494019..802538a 100644
--- a/Snippets/use-program-instanceswithtypes.swift
+++ b/Snippets/use-program-instanceswithtypes.swift
@@ -39,8 +39,8 @@ let p4_program_with_control_decl = """
 
 
 // snippet.include
-let flter = { (tipe: P4Type) -> Bool in
-  switch tipe.dataType(){
+let flter = { (tipe: P4QualifiedType) -> Bool in
+  switch tipe.baseType(){
   case let c as Control: c.name == "simple"
   default: false
   }
diff --git a/Sources/Common/Call.swift b/Sources/Common/Call.swift
index f365200..706f877 100644
--- a/Sources/Common/Call.swift
+++ b/Sources/Common/Call.swift
@@ -21,10 +21,10 @@ public struct Parameter: CustomStringConvertible, Equatable {
   }
 
   public var name: Identifier
-  public var type: P4Type
+  public var type: P4QualifiedType
 
   public init(
-    identifier: Identifier, withType type: P4Type
+    identifier: Identifier, withType type: P4QualifiedType
   ) {
     self.name = identifier
     self.type = type
@@ -46,7 +46,7 @@ public struct Parameter: CustomStringConvertible, Equatable {
         return false
       }
     }
-    return arg_type.dataType().eq(rhs: self.type.dataType())
+    return arg_type.baseType().eq(rhs: self.type.baseType())
   }
 
 }
diff --git a/Sources/Common/Compiler.swift b/Sources/Common/Compiler.swift
index c9f43ea..797b880 100644
--- a/Sources/Common/Compiler.swift
+++ b/Sources/Common/Compiler.swift
@@ -16,10 +16,10 @@
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
 /// A scope that resolves variable identifiers to their types.
-public typealias VarTypeScope = Scope<P4Type>
+public typealias VarTypeScope = Scope<P4QualifiedType>
 
 /// Scopes that resolve variable identifiers to their types.
-public typealias VarTypeScopes = Scopes<P4Type>
+public typealias VarTypeScopes = Scopes<P4QualifiedType>
 
 /// A scope that resolves type identifiers to their types.
 public typealias TypeTypeScope = Scope<P4DataType>
diff --git a/Sources/Common/DataTypes.swift b/Sources/Common/DataTypes.swift
index 2844584..abb4a8c 100644
--- a/Sources/Common/DataTypes.swift
+++ b/Sources/Common/DataTypes.swift
@@ -50,14 +50,14 @@ public class Identifier: CustomStringConvertible, Comparable, Hashable {
 
 /// A P4 identifier
 public class TypedIdentifier: Identifier {
-  public var type: P4Type
+  public var type: P4QualifiedType
 
-  public init(name: String, withType type: P4Type) {
+  public init(name: String, withType type: P4QualifiedType) {
     self.type = type
     super.init(name: name)
   }
 
-  public init(id: Identifier, withType type: P4Type) {
+  public init(id: Identifier, withType type: P4QualifiedType) {
     self.type = type
     super.init(id: id)
   }
@@ -107,7 +107,7 @@ public struct P4StructFields: Sequence, CustomStringConvertible, Equatable {
     }.joined(separator: ",")
   }
 
-  public func get_field_type(_ field: Identifier) -> P4Type? {
+  public func get_field_type(_ field: Identifier) -> P4QualifiedType? {
     if let found_field = self.fields.makeIterator().first(where: { current in
       return current.name == field.name
     }) {
@@ -566,13 +566,13 @@ public class Packet {
 
 /// A P4 array type
 public struct P4Array: P4DataType {
-  public init(withValueType vtype: P4Type) {
+  public init(withValueType vtype: P4QualifiedType) {
     self.vtype = vtype
   }
 
-  let vtype: P4Type
+  let vtype: P4QualifiedType
 
-  public func value_type() -> P4Type {
+  public func value_type() -> P4QualifiedType {
     return self.vtype
   }
 
@@ -599,9 +599,9 @@ public class P4ArrayValue: P4DataValue {
   }
 
   let value: [P4Value]
-  let vtype: P4Type
+  let vtype: P4QualifiedType
 
-  public init(withType type: P4Type, withValue value: [P4Value]) {
+  public init(withType type: P4QualifiedType, withValue value: [P4Value]) {
     self.vtype = type
     self.value = value
   }
@@ -664,13 +664,13 @@ public class P4ArrayValue: P4DataValue {
 
 /// A P4 set type
 public struct P4Set: P4DataType {
-  public init(withSetType stype: P4Type) {
+  public init(withSetType stype: P4QualifiedType) {
     self.stype = stype
   }
 
-  let stype: P4Type
+  let stype: P4QualifiedType
 
-  public func set_type() -> P4Type {
+  public func set_type() -> P4QualifiedType {
     return self.stype
   }
 
@@ -681,13 +681,13 @@ public struct P4Set: P4DataType {
   public func eq(rhs: any P4DataType) -> Bool {
     return switch rhs {
     // If rhs is a set type, then they are the same if the types in the set are the same.
-    case let srhs as P4Set: srhs.eq(rhs: self.stype.dataType())
+    case let srhs as P4Set: srhs.eq(rhs: self.stype.baseType())
     default: false
     }
   }
 
   public func def() -> P4DataValue {
-    return P4SetValue(withValue: P4Value(self.stype.dataType().def(), self.stype))
+    return P4SetValue(withValue: P4Value(self.stype.baseType().def(), self.stype))
   }
 }
 
@@ -748,9 +748,9 @@ public class P4SetDefaultValue: P4DataValue {
     return P4Set(withSetType: self.stype)
   }
 
-  let stype: P4Type
+  let stype: P4QualifiedType
 
-  public init(withType type: P4Type) {
+  public init(withType type: P4QualifiedType) {
     self.stype = type
   }
 
diff --git a/Sources/Common/FFI.swift b/Sources/Common/FFI.swift
index 821c780..02c0f11 100644
--- a/Sources/Common/FFI.swift
+++ b/Sources/Common/FFI.swift
@@ -17,6 +17,6 @@
 
 public protocol P4FFI {
   func execute(execution: ProgramExecution) -> (ControlFlow, ProgramExecution)
-  func type() -> P4Type
+  func type() -> P4QualifiedType
   func parameters() -> ParameterList
 }
diff --git a/Sources/Common/P4Types.swift b/Sources/Common/P4Types.swift
index 9c7dc82..29babb9 100644
--- a/Sources/Common/P4Types.swift
+++ b/Sources/Common/P4Types.swift
@@ -52,27 +52,27 @@ public enum Direction: Equatable, CustomStringConvertible {
   }
 }
 
-public enum P4TypeAttribute: Equatable {
+public enum P4TypeQualifier: Equatable {
   case Direction(Direction)
   case Readonly  // Not yet used -- here to keep Swift warnings at bay
 }
 
-public struct P4TypeAttributes: CustomStringConvertible {
-  let _attributes: [P4TypeAttribute]
+public struct P4TypeQualifiers: CustomStringConvertible {
+  let _qualifiers: [P4TypeQualifier]
 
-  public init(_ attributes: [P4TypeAttribute]) {
-    self._attributes = attributes
+  public init(_ qualifiers: [P4TypeQualifier]) {
+    self._qualifiers = qualifiers
   }
 
   public func direction() -> Direction? {
-    let result = _attributes.firstIndex { attribute in
+    let result = _qualifiers.firstIndex { attribute in
       return switch attribute {
       case .Direction(_): true
       default: false
       }
     }
     return result.flatMap { index in
-      return switch _attributes[index] {
+      return switch _qualifiers[index] {
       case .Direction(let d): d
       default: Optional<Direction>.none
       }
@@ -80,7 +80,7 @@ public struct P4TypeAttributes: CustomStringConvertible {
   }
 
   public func readOnly() -> Bool {
-    return _attributes.contains { attribute in
+    return _qualifiers.contains { attribute in
       return switch attribute {
       case .Readonly: true
       default: false
@@ -88,45 +88,45 @@ public struct P4TypeAttributes: CustomStringConvertible {
     }
   }
 
-  public func update(removeAttribute attributeToRemove: P4TypeAttribute) -> P4TypeAttributes {
-    var new_attributes = self._attributes
+  public func update(removeAttribute attributeToRemove: P4TypeQualifier) -> P4TypeQualifiers {
+    var new_attributes = self._qualifiers
     new_attributes.removeAll { item in
       return item == attributeToRemove
     }
-    return P4TypeAttributes(new_attributes)
+    return P4TypeQualifiers(new_attributes)
   }
 
-  public func update(addAttribute attributeToAdd: P4TypeAttribute) -> P4TypeAttributes {
-    return P4TypeAttributes(self._attributes + [attributeToAdd])
+  public func update(addAttribute attributeToAdd: P4TypeQualifier) -> P4TypeQualifiers {
+    return P4TypeQualifiers(self._qualifiers + [attributeToAdd])
   }
 
   public var description: String {
-    return self._attributes.map { attribute in
-      return "\(attribute)"
+    return self._qualifiers.map { qualifier in
+      return "\(qualifier)"
     }.joined(separator: ",")
   }
 
-  public static func ReadOnly() -> P4TypeAttributes {
-    return P4TypeAttributes([P4TypeAttribute.Readonly])
+  public static func ReadOnly() -> P4TypeQualifiers {
+    return P4TypeQualifiers([P4TypeQualifier.Readonly])
   }
 
 }
 
-public struct P4Type: CustomStringConvertible {
-  let _attributes: P4TypeAttributes
-  let _data_type: P4DataType
+public struct P4QualifiedType: CustomStringConvertible {
+  let _attributes: P4TypeQualifiers
+  let base_type: P4DataType
 
-  public init(_ type: P4DataType, _ attributes: P4TypeAttributes = P4TypeAttributes([])) {
+  public init(_ base_type: P4DataType, _ attributes: P4TypeQualifiers = P4TypeQualifiers([])) {
     self._attributes = attributes
-    self._data_type = type
+    self.base_type = base_type
   }
 
-  public func update(removeAttribute attribute: P4TypeAttribute) -> P4Type {
-    return P4Type(self._data_type, self._attributes.update(removeAttribute: attribute))
+  public func update(removeAttribute attribute: P4TypeQualifier) -> P4QualifiedType {
+    return P4QualifiedType(self.base_type, self._attributes.update(removeAttribute: attribute))
   }
 
-  public func update(addAttribute attribute: P4TypeAttribute) -> P4Type {
-    return P4Type(self._data_type, self._attributes.update(addAttribute: attribute))
+  public func update(addAttribute attribute: P4TypeQualifier) -> P4QualifiedType {
+    return P4QualifiedType(self.base_type, self._attributes.update(addAttribute: attribute))
   }
 
   public func direction() -> Direction? {
@@ -137,17 +137,17 @@ public struct P4Type: CustomStringConvertible {
     return self._attributes.readOnly()
   }
 
-  public func dataType() -> P4DataType {
-    return self._data_type
+  public func baseType() -> P4DataType {
+    return self.base_type
   }
 
   public func def() -> P4Value {
-    return P4Value(self._data_type.def(), self)
+    return P4Value(self.base_type.def(), self)
   }
 
-  public func eq(_ rhs: P4Type) -> Bool {
+  public func eq(_ rhs: P4QualifiedType) -> Bool {
     return self.direction() == rhs.direction() && self.readOnly() == self.readOnly()
-      && self.dataType().eq(rhs: rhs.dataType())
+      && self.baseType().eq(rhs: rhs.baseType())
   }
 
   public func assignable() -> TypeCheckResults {
@@ -163,8 +163,8 @@ public struct P4Type: CustomStringConvertible {
     return TypeCheckResults.Ok
   }
 
-  public func assignableFromType(_ rhs: P4Type) -> TypeCheckResults {
-    if !self.dataType().eq(rhs: rhs.dataType()) {
+  public func assignableFromType(_ rhs: P4QualifiedType) -> TypeCheckResults {
+    if !self.baseType().eq(rhs: rhs.baseType()) {
       return TypeCheckResults.IncompatibleTypes
     }
 
@@ -181,8 +181,8 @@ public struct P4Type: CustomStringConvertible {
     return TypeCheckResults.Ok
   }
 
-  public static func ReadOnly(_ type: P4DataType) -> P4Type {
-    return P4Type(type, P4TypeAttributes.ReadOnly())
+  public static func ReadOnly(_ type: P4DataType) -> P4QualifiedType {
+    return P4QualifiedType(type, P4TypeQualifiers.ReadOnly())
   }
 
   public var description: String {
@@ -190,17 +190,17 @@ public struct P4Type: CustomStringConvertible {
     if !attributes_description.isEmpty {
       attributes_description += " "
     }
-    return "\(attributes_description)\(self._data_type)"
+    return "\(attributes_description)\(self.base_type)"
   }
 }
 
 public struct P4Value: CustomStringConvertible {
   let _value: P4DataValue
-  let _type: P4Type
+  let _type: P4QualifiedType
 
-  public init(_ value: P4DataValue, _ type: P4Type? = .none) {
+  public init(_ value: P4DataValue, _ type: P4QualifiedType? = .none) {
     self._value = value
-    self._type = type != nil ? type! : P4Type(value.type())
+    self._type = type != nil ? type! : P4QualifiedType(value.type())
   }
 
   public func update(withNewValue value: P4DataValue) -> Result<P4Value> {
@@ -212,7 +212,7 @@ public struct P4Value: CustomStringConvertible {
     return "Value: \(self._value) of type \(self._type)"
   }
 
-  public func type() -> P4Type {
+  public func type() -> P4QualifiedType {
     return self._type
   }
 
diff --git a/Sources/Common/Protocols.swift b/Sources/Common/Protocols.swift
index 41a22b2..272d37b 100644
--- a/Sources/Common/Protocols.swift
+++ b/Sources/Common/Protocols.swift
@@ -21,7 +21,7 @@ public protocol EvaluatableExpression {
   ///  - execution: The execution context in which to evaluate the expression
   /// - Returns: The value of expression
   func evaluate(execution: ProgramExecution) -> (Result<P4Value>, ProgramExecution)
-  func type() -> P4Type
+  func type() -> P4QualifiedType
 }
 
 public protocol EvaluatableStatement {
diff --git a/Sources/P4Compiler/Common.swift b/Sources/P4Compiler/Common.swift
index 707525f..b6cc1c5 100644
--- a/Sources/P4Compiler/Common.swift
+++ b/Sources/P4Compiler/Common.swift
@@ -229,7 +229,7 @@ extension Parameter: Compilable {
         Parameter(
           identifier: parameter_name,
           withType: direction != nil
-            ? parameter_type.update(addAttribute: P4TypeAttribute.Direction(direction!))
+            ? parameter_type.update(addAttribute: P4TypeQualifier.Direction(direction!))
             : parameter_type),
         context
       ))
diff --git a/Sources/P4Compiler/Compiler.swift b/Sources/P4Compiler/Compiler.swift
index 8afaf30..1321cf5 100644
--- a/Sources/P4Compiler/Compiler.swift
+++ b/Sources/P4Compiler/Compiler.swift
@@ -54,7 +54,7 @@ public struct CompilerContext {
   let types: TypeTypeScopes
   let externs: TypeTypeScopes
   let ffis: [P4FFI]
-  let expected_type: P4Type?
+  let expected_type: P4QualifiedType?
   let extern_context: Bool
 
   public init() {
@@ -77,7 +77,7 @@ public struct CompilerContext {
 
   public init(
     withInstances _instances: VarTypeScopes, withTypes _types: TypeTypeScopes,
-    withExpectation expectation: P4Type?, withExtern extern: Bool,
+    withExpectation expectation: P4QualifiedType?, withExtern extern: Bool,
     withExterns externs: TypeTypeScopes, withFFIs foreigns: [P4FFI]
   ) {
     instances = _instances
@@ -118,7 +118,7 @@ public struct CompilerContext {
   ///
   /// - Parameter expectation: a ``P4Type?`` to (re)set the type the compiler is expecting.
   /// - Returns: A new compiler context based on the current but new expected type.
-  public func update(newExpectation expectation: P4Type?) -> CompilerContext {
+  public func update(newExpectation expectation: P4QualifiedType?) -> CompilerContext {
     return CompilerContext(
       withInstances: self.instances, withTypes: self.types, withExpectation: expectation,
       withExtern: self.extern_context, withExterns: self.externs, withFFIs: self.ffis)
diff --git a/Sources/P4Compiler/Declarations.swift b/Sources/P4Compiler/Declarations.swift
index f8d604f..25e9799 100644
--- a/Sources/P4Compiler/Declarations.swift
+++ b/Sources/P4Compiler/Declarations.swift
@@ -128,7 +128,7 @@ extension FunctionDeclaration: CompilableDeclaration {
     let function_declaration = Declaration(
       TypedIdentifier(
         id: function_name,
-        withType: P4Type(
+        withType: P4QualifiedType(
           FunctionDeclaration(
             named: function_name, ofType: function_type, withParameters: function_parameters,
             withBody: function_body))))
@@ -144,7 +144,7 @@ extension FunctionDeclaration: CompilableDeclaration {
           ? context
           : context.update(
             newTypes: context.types.declare(
-              identifier: function_name, withValue: function_declaration.identifier.type.dataType())
+              identifier: function_name, withValue: function_declaration.identifier.type.baseType())
           )
       ))
   }
@@ -189,7 +189,7 @@ extension P4Struct: CompilableDeclaration {
       let struc = Declaration(
         TypedIdentifier(
           id: struct_identifier,
-          withType: P4Type(P4Struct(withName: struct_identifier, andFields: P4StructFields([])))))
+          withType: P4QualifiedType(P4Struct(withName: struct_identifier, andFields: P4StructFields([])))))
       return Result.Ok(
         (
           struc,
@@ -197,7 +197,7 @@ extension P4Struct: CompilableDeclaration {
             ? context
             : context.update(
               newTypes: context.types.declare(
-                identifier: struct_identifier, withValue: struc.identifier.type.dataType()))
+                identifier: struct_identifier, withValue: struc.identifier.type.baseType()))
         ))
     }
 
@@ -234,7 +234,7 @@ extension P4Struct: CompilableDeclaration {
     let declared_struct = Declaration(
       TypedIdentifier(
         id: struct_identifier,
-        withType: P4Type(
+        withType: P4QualifiedType(
           P4Struct(
             withName: struct_identifier, andFields: P4StructFields(parsed_fields)))))
     return .Ok(
@@ -244,7 +244,7 @@ extension P4Struct: CompilableDeclaration {
           ? current_context
           : current_context.update(
             newTypes: current_context.types.declare(
-              identifier: struct_identifier, withValue: declared_struct.identifier.type.dataType()))
+              identifier: struct_identifier, withValue: declared_struct.identifier.type.baseType()))
       ))
   }
 }
@@ -366,7 +366,7 @@ extension P4Lang.Parser: CompilableDeclaration {
     {
     case Result.Ok((let parser, let updated_context)):
       let parser_declaration = Declaration(
-        TypedIdentifier(id: parser.name, withType: P4Type(parser)))
+        TypedIdentifier(id: parser.name, withType: P4QualifiedType(parser)))
       // Create a new context with the name of the parser that was just compiled in scope.
       return .Ok(
         (
@@ -518,7 +518,7 @@ extension Control: CompilableDeclaration {
       Declaration(
         TypedIdentifier(
           id: control_name,
-          withType: P4Type(
+          withType: P4QualifiedType(
             Control(
               named: control_name, withParameters: control_parameters, withTable: tables[0],
               withActions: Actions(withActions: actions), withApply: apply))))
@@ -753,7 +753,7 @@ extension TableActionsProperty: Compilable {
         switch context.types.lookup(identifier: listed_action) {
         case .Ok(let maybe_action):
           if maybe_action.eq(rhs: Action()) {
-            return .Ok(TypedIdentifier(id: listed_action, withType: P4Type(maybe_action)))
+            return .Ok(TypedIdentifier(id: listed_action, withType: P4QualifiedType(maybe_action)))
           }
           return .Error(
             ErrorOnNode(node: node, withError: "\(listed_action) does not name an action"))
@@ -923,7 +923,7 @@ extension ExternDeclaration: CompilableDeclaration {
     // with the matching "stuff".
 
     let found_ffi = context.ffis.first { ffi in
-      ffi.type().dataType().eq(rhs: declared.identifier.type.dataType())
+      ffi.type().baseType().eq(rhs: declared.identifier.type.baseType())
     }
 
     guard let found_ffi = found_ffi else {
diff --git a/Sources/P4Compiler/Expression.swift b/Sources/P4Compiler/Expression.swift
index c0160f5..625a8f9 100644
--- a/Sources/P4Compiler/Expression.swift
+++ b/Sources/P4Compiler/Expression.swift
@@ -392,49 +392,49 @@ extension BinaryOperatorExpression: CompilableExpression {
       return Result.Error(maybe_right_hand_side.error()!)
     }
 
-    let evaluators: [String: (String, P4Type, BinaryOperatorChecker?, BinaryOperatorEvaluator)] = [
+    let evaluators: [String: (String, P4QualifiedType, BinaryOperatorChecker?, BinaryOperatorEvaluator)] = [
       "binaryEqualOperatorExpression": (
-        "Binary Equal", P4Type(P4Boolean()), Optional<BinaryOperatorChecker>.none,
+        "Binary Equal", P4QualifiedType(P4Boolean()), Optional<BinaryOperatorChecker>.none,
         binary_equal_operator_evaluator
       ),
       "binaryLessThanOperatorExpression": (
-        "Binary Less Than", P4Type(P4Boolean()), Optional<BinaryOperatorChecker>.none,
+        "Binary Less Than", P4QualifiedType(P4Boolean()), Optional<BinaryOperatorChecker>.none,
         binary_lt_operator_evaluator
       ),
       "binaryLessThanEqualOperatorExpression": (
-        "Binary Less Than Or Equal", P4Type(P4Boolean()), Optional<BinaryOperatorChecker>.none,
+        "Binary Less Than Or Equal", P4QualifiedType(P4Boolean()), Optional<BinaryOperatorChecker>.none,
         binary_lte_operator_evaluator
       ),
       "binaryGreaterThanOperatorExpression": (
-        "Binary Greater Than", P4Type(P4Boolean()), Optional<BinaryOperatorChecker>.none,
+        "Binary Greater Than", P4QualifiedType(P4Boolean()), Optional<BinaryOperatorChecker>.none,
         binary_gt_operator_evaluator
       ),
       "binaryGreaterThanEqualOperatorExpression": (
-        "Binary Greater Than Or Equal", P4Type(P4Boolean()), Optional<BinaryOperatorChecker>.none,
+        "Binary Greater Than Or Equal", P4QualifiedType(P4Boolean()), Optional<BinaryOperatorChecker>.none,
         binary_gte_operator_evaluator
       ),
       "binaryAndOperatorExpression": (
-        "Binary Or", P4Type(P4Boolean()), binary_and_or_operator_checker,
+        "Binary Or", P4QualifiedType(P4Boolean()), binary_and_or_operator_checker,
         binary_and_operator_evaluator
       ),
       "binaryOrOperatorExpression": (
-        "Binary And", P4Type(P4Boolean()), binary_and_or_operator_checker,
+        "Binary And", P4QualifiedType(P4Boolean()), binary_and_or_operator_checker,
         binary_or_operator_evaluator
       ),
       "binaryAddOperatorExpression": (
-        "Binary Add", P4Type(P4Int()), binary_int_math_operator_checker,
+        "Binary Add", P4QualifiedType(P4Int()), binary_int_math_operator_checker,
         binary_add_operator_evaluator
       ),
       "binarySubtractOperatorExpression": (
-        "Binary Subtract", P4Type(P4Int()), binary_int_math_operator_checker,
+        "Binary Subtract", P4QualifiedType(P4Int()), binary_int_math_operator_checker,
         binary_subtract_operator_evaluator
       ),
       "binaryMultiplyOperatorExpression": (
-        "Binary Multiply", P4Type(P4Int()), binary_int_math_operator_checker,
+        "Binary Multiply", P4QualifiedType(P4Int()), binary_int_math_operator_checker,
         binary_multiply_operator_evaluator
       ),
       "binaryDivideOperatorExpression": (
-        "Binary Divide", P4Type(P4Int()), binary_int_math_operator_checker,
+        "Binary Divide", P4QualifiedType(P4Int()), binary_int_math_operator_checker,
         binary_divide_operator_evaluator
       ),
     ]
@@ -510,7 +510,7 @@ extension ArrayAccessExpression: CompilableExpression {
     }
 
     let maybe_array_type = array_identifier.type()
-    guard let array_type = maybe_array_type.dataType() as? P4Array else {
+    guard let array_type = maybe_array_type.baseType() as? P4Array else {
       return Result.Error(
         ErrorOnNode(
           node: array_access_identifier_node,
@@ -581,7 +581,7 @@ extension FieldAccessExpression: CompilableExpression {
     guard case Result.Ok(let struct_identifier) = maybe_struct_identifier else {
       return Result.Error(maybe_struct_identifier.error()!)
     }
-    guard let struct_type = struct_identifier.type().dataType() as? P4Struct else {
+    guard let struct_type = struct_identifier.type().baseType() as? P4Struct else {
       return .Error(
         ErrorOnNode(
           node: struct_identifier_node,
@@ -690,7 +690,7 @@ extension FunctionCall: CompilableExpression {
         switch context.externs.lookup(identifier: callee_name) {
         case .Ok(let callee as Declaration):
           // Now, make sure that it is a function declaration!
-          switch callee.identifier.type.dataType() {
+          switch callee.identifier.type.baseType() {
           case is FunctionDeclaration: Result.Ok((.none, callee))
           default:
             .Error(ErrorOnNode(node: current_node!, withError: "\(callee_name) is not a function"))
@@ -725,7 +725,7 @@ extension FunctionCall: CompilableExpression {
       switch callee {
       case (.some(let callee), .none): Optional<ParameterList>.some(callee.params)
       case (.none, .some(let callee)):
-        Optional<ParameterList>.some((callee.ffi!.type().dataType() as! FunctionDeclaration).params)
+        Optional<ParameterList>.some((callee.ffi!.type().baseType() as! FunctionDeclaration).params)
       default: Optional<ParameterList>.none
       }
 
diff --git a/Sources/P4Compiler/Statement.swift b/Sources/P4Compiler/Statement.swift
index 5be841e..87c42a1 100644
--- a/Sources/P4Compiler/Statement.swift
+++ b/Sources/P4Compiler/Statement.swift
@@ -312,7 +312,7 @@ extension ReturnStatement: CompilableStatement {
 
     return switch Expression.Compile(node: expression_node, withContext: context) {
     case .Ok(let result):
-      if result.type().dataType().eq(rhs: context.expected_type!.dataType()) {
+      if result.type().baseType().eq(rhs: context.expected_type!.baseType()) {
         .Ok((ReturnStatement(result), context))
       } else {
         .Error(
diff --git a/Sources/P4Compiler/Types.swift b/Sources/P4Compiler/Types.swift
index aec0c27..685ae72 100644
--- a/Sources/P4Compiler/Types.swift
+++ b/Sources/P4Compiler/Types.swift
@@ -68,13 +68,13 @@ extension P4Struct: CompilableType {
 public struct Types {
   static func CompileType(
     type: SwiftTreeSitter.Node, withContext context: CompilerContext
-  ) -> Result<P4Type> {
+  ) -> Result<P4QualifiedType> {
     let type_parsers: [CompilableType.Type] = [
       P4Boolean.self, P4Int.self, P4String.self, P4Struct.self,
     ]
     for type_parser in type_parsers {
       switch type_parser.CompileType(type: type, withContext: context) {
-      case .Ok(.some(let type)): return .Ok(P4Type(type))
+      case .Ok(.some(let type)): return .Ok(P4QualifiedType(type))
       case .Ok(.none): continue
       case .Error(let e): return .Error(e)
       }
diff --git a/Sources/P4Lang/Declarations.swift b/Sources/P4Lang/Declarations.swift
index ef01350..be2294f 100644
--- a/Sources/P4Lang/Declarations.swift
+++ b/Sources/P4Lang/Declarations.swift
@@ -37,7 +37,7 @@ public struct Declaration: P4DataType {
   public func eq(rhs: any Common.P4DataType) -> Bool {
     return switch rhs {
     case let rrhs as Declaration:
-      self.identifier.type.dataType().eq(rhs: rrhs.identifier.type.dataType())
+      self.identifier.type.baseType().eq(rhs: rrhs.identifier.type.baseType())
         && self.extern == rrhs.extern
     default: false
     }
@@ -45,7 +45,7 @@ public struct Declaration: P4DataType {
 
   public func def() -> any Common.P4DataValue {
     /// TODO: Is a default of the extern'd type the right way to go?
-    return self.identifier.type.dataType().def()
+    return self.identifier.type.baseType().def()
   }
 
   public func type() -> any Common.P4DataType {
@@ -109,7 +109,7 @@ public struct FunctionDeclaration: P4DataType, P4DataValue {
 
   public func def() -> any Common.P4DataValue {
     return FunctionDeclaration(
-      named: Identifier(name: ""), ofType: P4Type(P4Boolean()),
+      named: Identifier(name: ""), ofType: P4QualifiedType(P4Boolean()),
       withParameters: ParameterList([]),
       withBody: .none)
   }
@@ -121,10 +121,10 @@ public struct FunctionDeclaration: P4DataType, P4DataValue {
   public var body: BlockStatement?
   public var params: ParameterList
   public var name: Identifier
-  public var tipe: P4Type
+  public var tipe: P4QualifiedType
 
   public init(
-    named name: Identifier, ofType type: P4Type, withParameters parameters: ParameterList,
+    named name: Identifier, ofType type: P4QualifiedType, withParameters parameters: ParameterList,
     withBody body: BlockStatement?
   ) {
     self.name = name
diff --git a/Sources/P4Lang/Expressions.swift b/Sources/P4Lang/Expressions.swift
index 6029037..9d1611d 100644
--- a/Sources/P4Lang/Expressions.swift
+++ b/Sources/P4Lang/Expressions.swift
@@ -24,8 +24,8 @@ public struct KeysetExpression {
     self.key = key
   }
 
-  public func compatible(type: P4Type) -> Result<()> {
-    if let key_type = self.key.type().dataType() as? P4Set {
+  public func compatible(type: P4QualifiedType) -> Result<()> {
+    if let key_type = self.key.type().baseType() as? P4Set {
       if !key_type.set_type().eq(type) {
         return .Error(
           Error(
@@ -84,7 +84,7 @@ public struct SelectExpression {
   }
 }
 
-public typealias NamedBinaryOperatorEvaluator = (String, P4Type, (P4Value, P4Value) -> P4DataValue)
+public typealias NamedBinaryOperatorEvaluator = (String, P4QualifiedType, (P4Value, P4Value) -> P4DataValue)
 public typealias BinaryOperatorEvaluator = (P4Value, P4Value) -> P4DataValue
 
 public struct BinaryOperatorExpression {
@@ -135,13 +135,13 @@ public struct FunctionCall {
   public init(_ callee: FunctionDeclaration, withArguments arguments: ArgumentList) {
     self.callee = (callee, .none)
     self.arguments = arguments
-    self.return_type = callee.tipe.dataType()
+    self.return_type = callee.tipe.baseType()
   }
 
   public init(_ callee: P4FFI, withArguments arguments: ArgumentList) {
     self.callee = (.none, callee)
     self.arguments = arguments
     /// ASSUME: That the FFI has been checked and the type is always a function declaration.
-    self.return_type = (callee.type().dataType() as! FunctionDeclaration).tipe.dataType()
+    self.return_type = (callee.type().baseType() as! FunctionDeclaration).tipe.baseType()
   }
 }
diff --git a/Sources/P4Lang/Program.swift b/Sources/P4Lang/Program.swift
index aaa4072..6d78a23 100644
--- a/Sources/P4Lang/Program.swift
+++ b/Sources/P4Lang/Program.swift
@@ -28,15 +28,15 @@ public struct ExpressionStatement {
 public struct Program {
   public var types: [P4DataType] = Array()
   public var externs: [P4DataType] = Array()
-  public var instances: [P4Type] = Array()
+  public var instances: [P4QualifiedType] = Array()
 
   /// Type of closure for filtering results from ``Program/InstancesWithTypes(_:)``
-  public typealias TypeFilter = (P4Type) -> Bool
+  public typealias TypeFilter = (P4QualifiedType) -> Bool
   /// Type of closure for filtering results from ``Program/TypesWithTypes(_:)``
   public typealias DataTypeFilter = (P4DataType) -> Bool
 
   /// Retrieve global instances in the compiled P4 program.
-  public func InstancesWithTypes() -> [P4Type] {
+  public func InstancesWithTypes() -> [P4QualifiedType] {
     return self.instances
   }
 
@@ -52,7 +52,7 @@ public struct Program {
   ///
   /// @Snippet(path: "use-program-instanceswithtypes", slice: "include")
   ///
-  public func InstancesWithTypes(_ filter: TypeFilter) -> [P4Type] {
+  public func InstancesWithTypes(_ filter: TypeFilter) -> [P4QualifiedType] {
     return self.instances.filter { instance in
       filter(instance)
     }
@@ -113,7 +113,7 @@ public struct Program {
 
   public func find_parser(withName name: Identifier) -> Result<Parser> {
     for instance in self.instances {
-      guard let parser = instance.dataType() as? Parser else {
+      guard let parser = instance.baseType() as? Parser else {
         continue
       }
       if parser.name == name {
diff --git a/Sources/P4Lang/Types.swift b/Sources/P4Lang/Types.swift
index 15ce50a..d4ce6b3 100644
--- a/Sources/P4Lang/Types.swift
+++ b/Sources/P4Lang/Types.swift
@@ -19,9 +19,9 @@ import Common
 
 public struct AttributedP4Type {
   public let type: P4DataType
-  public let attributes: P4Type
+  public let attributes: P4QualifiedType
 
-  public init(_ type: P4DataType, _ attributes: P4Type) {
+  public init(_ type: P4DataType, _ attributes: P4QualifiedType) {
     self.type = type
     self.attributes = attributes
   }
diff --git a/Sources/P4Runtime/Expressions.swift b/Sources/P4Runtime/Expressions.swift
index f899729..8909ba9 100644
--- a/Sources/P4Runtime/Expressions.swift
+++ b/Sources/P4Runtime/Expressions.swift
@@ -23,8 +23,8 @@ extension SelectCaseExpression: EvaluatableExpression {
     return (execution.scopes.lookup(identifier: next_state_identifier), execution)
   }
 
-  public func type() -> P4Type {
-    return P4Type(ParserState())
+  public func type() -> P4QualifiedType {
+    return P4QualifiedType(ParserState())
   }
 }
 
@@ -49,14 +49,14 @@ extension SelectExpression: EvaluatableExpression {
     }
   }
 
-  public func type() -> P4Type {
-    return P4Type(ParserState())
+  public func type() -> P4QualifiedType {
+    return P4QualifiedType(ParserState())
   }
 }
 
 // Variables are evaluatable because they can be looked up by identifiers.
 extension TypedIdentifier: EvaluatableExpression {
-  public func type() -> P4Type {
+  public func type() -> P4QualifiedType {
     return self.type
   }
 
@@ -192,7 +192,7 @@ public func binary_and_or_operator_checker(
   left: EvaluatableExpression, right: EvaluatableExpression
 ) -> Result<()> {
   // Check that both are Boolean-typed things!
-  if !(left.type().dataType().eq(rhs: P4Boolean()) && right.type().dataType().eq(rhs: P4Boolean()))
+  if !(left.type().baseType().eq(rhs: P4Boolean()) && right.type().baseType().eq(rhs: P4Boolean()))
   {
     return .Error(Error(withMessage: "And/Or on operands with non-bool type is not allowed"))
   }
@@ -203,7 +203,7 @@ public func binary_int_math_operator_checker(
   left: EvaluatableExpression, right: EvaluatableExpression
 ) -> Result<()> {
   // Check that both are int-typed things!
-  if !(left.type().dataType().eq(rhs: P4Int()) && right.type().dataType().eq(rhs: P4Int())) {
+  if !(left.type().baseType().eq(rhs: P4Int()) && right.type().baseType().eq(rhs: P4Int())) {
     return .Error(
       Error(withMessage: "Mathematical operation on operands with non-int type is not allowed"))
   }
@@ -230,7 +230,7 @@ extension BinaryOperatorExpression: EvaluatableExpression {
     return (.Ok(P4Value(self.evaluator.2(evaluated_left, evaluated_right))), updated_execution)
   }
 
-  public func type() -> P4Type {
+  public func type() -> P4QualifiedType {
     return self.evaluator.1
   }
 }
@@ -264,7 +264,7 @@ extension ArrayAccessExpression: EvaluatableExpression {
     return (.Ok(accessed), updated_execution)
   }
 
-  public func type() -> P4Type {
+  public func type() -> P4QualifiedType {
     return self.type.value_type()
   }
 }
@@ -375,7 +375,7 @@ extension FieldAccessExpression: EvaluatableExpression {
     return (.Ok(value), updated_execution)
   }
 
-  public func type() -> P4Type {
+  public func type() -> P4QualifiedType {
     return self.field.type
   }
 }
@@ -467,7 +467,7 @@ extension KeysetExpression: EvaluatableExpression {
     return execution.evaluator.EvaluateExpression(self.key, inExecution: execution)
   }
 
-  public func type() -> P4Type {
+  public func type() -> P4QualifiedType {
     return self.key.type()
   }
 }
@@ -524,8 +524,8 @@ extension FunctionCall: EvaluatableExpression {
       inExecution: execution)
   }
 
-  public func type() -> P4Type {
-    return P4Type(self.return_type)
+  public func type() -> P4QualifiedType {
+    return P4QualifiedType(self.return_type)
   }
 }
 
diff --git a/Sources/P4Runtime/Parser.swift b/Sources/P4Runtime/Parser.swift
index 281bd0f..9dbc763 100644
--- a/Sources/P4Runtime/Parser.swift
+++ b/Sources/P4Runtime/Parser.swift
@@ -62,7 +62,7 @@ extension ParserStateDirectTransition: EvaluatableParserState {
     let res = program.scopes.lookup(identifier: get_next_state())
 
     if case .Ok(let value) = res {
-      if value.type().dataType().eq(rhs: self) {
+      if value.type().baseType().eq(rhs: self) {
         return (value.dataValue() as! EvaluatableParserState, program.exit_scope())
       }
     }
@@ -119,7 +119,7 @@ extension ParserStateSelectTransition: EvaluatableParserState {
     //switch self.selectExpression.evaluate(execution: program) {
     switch program.evaluator.EvaluateExpression(self.selectExpression, inExecution: program) {
     case (.Ok(let value), let program):
-      if value.type().dataType().eq(rhs: self) {
+      if value.type().baseType().eq(rhs: self) {
         return (value.dataValue() as! EvaluatableParserState, program.exit_scope())
       } else {
         return (
@@ -150,10 +150,10 @@ extension Parser: LibraryCallable {
 
     execution = execution.declare(
       identifier: AsInstantiatedParserState(accept.state()).state,
-      withValue: P4Value(accept, P4Type.ReadOnly(accept.type())))
+      withValue: P4Value(accept, P4QualifiedType.ReadOnly(accept.type())))
     execution = execution.declare(
       identifier: AsInstantiatedParserState(reject.state()).state,
-      withValue: P4Value(reject, P4Type.ReadOnly(reject.type())))
+      withValue: P4Value(reject, P4QualifiedType.ReadOnly(reject.type())))
 
     // Add initial values to the global scope
     for (name, value) in execution.getGlobalValues() {
diff --git a/Sources/P4Runtime/Statements.swift b/Sources/P4Runtime/Statements.swift
index 4749346..6063c33 100644
--- a/Sources/P4Runtime/Statements.swift
+++ b/Sources/P4Runtime/Statements.swift
@@ -69,7 +69,7 @@ extension ConditionalStatement: EvaluatableStatement {
       )
     }
 
-    if !evaluated_condition.type().dataType().eq(rhs: P4Boolean()) {
+    if !evaluated_condition.type().baseType().eq(rhs: P4Boolean()) {
       return (
         ControlFlow.Error,
         execution.setError(error: Error(withMessage: "Condition expression is not a Boolean"))
diff --git a/Tests/p4rseTests/ArrayTests.swift b/Tests/p4rseTests/ArrayTests.swift
index 1790d61..45ac2ff 100644
--- a/Tests/p4rseTests/ArrayTests.swift
+++ b/Tests/p4rseTests/ArrayTests.swift
@@ -40,11 +40,11 @@ import TreeSitterP4
       };
     """
   var test_declarations = VarTypeScopes().enter()
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4Type(P4Array(withValueType: P4Type(P4Int()))))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Int()))))
   var test_values = VarValueScopes().enter()
   test_values = test_values.declare(
     identifier: Identifier(name: "ta"),
-    withValue: P4Value(P4ArrayValue(withType: P4Type(P4Int()), withValue: [
+    withValue: P4Value(P4ArrayValue(withType: P4QualifiedType(P4Int()), withValue: [
       P4Value(P4IntValue(withValue: 1)), P4Value(P4IntValue(withValue: 2)), P4Value(P4IntValue(withValue: 3))
     ])))
   let program = try #UseOkResult(
@@ -68,7 +68,7 @@ import TreeSitterP4
       };
     """
   var test_declarations = VarTypeScopes().enter()
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4Type(P4Int()))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4QualifiedType(P4Int()))
   #expect(
     #RequireErrorResult(
       Error(
@@ -91,12 +91,12 @@ import TreeSitterP4
       };
     """
   var test_declarations = VarTypeScopes().enter()
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4Type(P4Array(withValueType: P4Type(P4Int()))))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Int()))))
   var test_values = VarValueScopes().enter()
 
   test_values = test_values.declare(
     identifier: Identifier(name: "ta"),
-    withValue: P4Value(P4ArrayValue(withType: P4Type(P4Int()), withValue: [
+    withValue: P4Value(P4ArrayValue(withType: P4QualifiedType(P4Int()), withValue: [
       P4Value(P4IntValue(withValue: 1)), P4Value(P4IntValue(withValue: 2)), P4Value(P4IntValue(withValue: 3))
     ])))
   let program = try #UseOkResult(
@@ -119,11 +119,11 @@ import TreeSitterP4
       };
     """
   var test_declarations = VarTypeScopes().enter()
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4Type(P4Array(withValueType: P4Type(P4Int()))))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Int()))))
   var test_values = VarValueScopes().enter()
   test_values = test_values.declare(
     identifier: Identifier(name: "ta"),
-    withValue: P4Value(P4ArrayValue(withType: P4Type(P4Int()), withValue: [
+    withValue: P4Value(P4ArrayValue(withType: P4QualifiedType(P4Int()), withValue: [
       P4Value(P4IntValue(withValue: 1)), P4Value(P4IntValue(withValue: 2)), P4Value(P4IntValue(withValue: 3)),
     ])))
   let program = try #UseOkResult(
@@ -146,11 +146,11 @@ import TreeSitterP4
       };
     """
   var test_declarations = VarTypeScopes().enter()
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4Type(P4Array(withValueType: P4Type(P4Int()))))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Int()))))
   var test_values = VarValueScopes().enter()
   test_values = test_values.declare(
     identifier: Identifier(name: "ta"),
-    withValue: P4Value(P4ArrayValue(withType: P4Type(P4Int()), withValue: [
+    withValue: P4Value(P4ArrayValue(withType: P4QualifiedType(P4Int()), withValue: [
       P4Value(P4IntValue(withValue: 1)), P4Value(P4IntValue(withValue: 2)), P4Value(P4IntValue(withValue: 3)),
     ])))
   let program = try #UseOkResult(
@@ -174,16 +174,16 @@ import TreeSitterP4
       };
     """
   var test_declarations = VarTypeScopes().enter()
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4Type(P4Array(withValueType: P4Type(P4Array(withValueType: P4Type(P4Int()))))))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Int()))))))
   var test_values = VarValueScopes().enter()
 
   let nested = P4Value(P4ArrayValue(
-    withType: P4Type(P4Int()),
+    withType: P4QualifiedType(P4Int()),
     withValue: [P4Value(P4IntValue(withValue: 5)), P4Value(P4IntValue(withValue: 2)), P4Value(P4IntValue(withValue: 3))]))
 
   test_values = test_values.declare(
     identifier: Identifier(name: "ta"),
-    withValue: P4Value(P4ArrayValue(withType: P4Type(P4Array(withValueType: P4Type(P4Int()))), withValue: [nested])))
+    withValue: P4Value(P4ArrayValue(withType: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Int()))), withValue: [nested])))
 
   let program = try #UseOkResult(
     Program.Compile(simple_parser_declaration, withGlobalInstances: test_declarations))
@@ -207,11 +207,11 @@ import TreeSitterP4
       };
     """
   var test_declarations = VarTypeScopes().enter()
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4Type(P4Array(withValueType: P4Type(P4Int()))))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Int()))))
   var test_values = VarValueScopes().enter()
   test_values = test_values.declare(
     identifier: Identifier(name: "ta"),
-    withValue: P4Value(P4ArrayValue(withType: P4Type(P4Int()), withValue: [
+    withValue: P4Value(P4ArrayValue(withType: P4QualifiedType(P4Int()), withValue: [
       P4Value(P4IntValue(withValue: 1)), P4Value(P4IntValue(withValue: 2)), P4Value(P4IntValue(withValue: 3)),
     ])))
   let program = try #UseOkResult(
@@ -236,16 +236,16 @@ import TreeSitterP4
       };
     """
   var test_declarations = VarTypeScopes().enter()
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4Type(P4Array(withValueType: P4Type(P4Array(withValueType: P4Type(P4Int()))))))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ta"), withValue: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Int()))))))
   var test_values = VarValueScopes().enter()
 
   let nested = P4Value(P4ArrayValue(
-    withType: P4Type(P4Int()),
+    withType: P4QualifiedType(P4Int()),
     withValue: [P4Value(P4IntValue(withValue: 1)), P4Value(P4IntValue(withValue: 2)), P4Value(P4IntValue(withValue: 3))]))
 
   test_values = test_values.declare(
     identifier: Identifier(name: "ta"),
-    withValue: P4Value(P4ArrayValue(withType: P4Type(P4Array(withValueType: P4Type(P4Int()))), withValue: [nested])))
+    withValue: P4Value(P4ArrayValue(withType: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Int()))), withValue: [nested])))
 
   let program = try #UseOkResult(
     Program.Compile(simple_parser_declaration, withGlobalInstances: test_declarations))
diff --git a/Tests/p4rseTests/BinaryOperatorTests/Struct.swift b/Tests/p4rseTests/BinaryOperatorTests/Struct.swift
index e7c12a6..4dcf9b0 100644
--- a/Tests/p4rseTests/BinaryOperatorTests/Struct.swift
+++ b/Tests/p4rseTests/BinaryOperatorTests/Struct.swift
@@ -42,8 +42,8 @@ import TreeSitterP4
     """
   let test_declarations = VarTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   var test_types = TypeTypeScopes().enter()
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
@@ -75,8 +75,8 @@ import TreeSitterP4
     """
   let test_declarations = VarTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   var test_types = TypeTypeScopes().enter()
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
@@ -109,8 +109,8 @@ import TreeSitterP4
     """
   let test_declarations = VarTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   var test_types = TypeTypeScopes().enter()
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
@@ -146,8 +146,8 @@ import TreeSitterP4
     """
   let test_declarations = VarTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   var test_types = TypeTypeScopes().enter()
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
@@ -183,8 +183,8 @@ import TreeSitterP4
     """
   let test_declarations = VarTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   var test_types = TypeTypeScopes().enter()
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
diff --git a/Tests/p4rseTests/ControlTests/Compile.swift b/Tests/p4rseTests/ControlTests/Compile.swift
index 140d3be..713aeef 100644
--- a/Tests/p4rseTests/ControlTests/Compile.swift
+++ b/Tests/p4rseTests/ControlTests/Compile.swift
@@ -41,8 +41,8 @@ import P4Lang
       }
     };
     """
-  let x = { (tipe: P4Type) -> Bool in
-    switch tipe.dataType() {
+  let x = { (tipe: P4QualifiedType) -> Bool in
+    switch tipe.baseType() {
     case let c as Control: c.name == "simple"
     default: false
     }
@@ -79,8 +79,8 @@ import P4Lang
     };
     """
 
-  let filter = { (tipe: P4Type) -> Bool in
-    switch tipe.dataType() {
+  let filter = { (tipe: P4QualifiedType) -> Bool in
+    switch tipe.baseType() {
     case let c as Control: c.name == "simple" || c.name == "complex"
     default: false
     }
@@ -106,8 +106,8 @@ import P4Lang
       }
     };
     """
-  let x = { (tipe: P4Type) -> Bool in
-    switch tipe.dataType() {
+  let x = { (tipe: P4QualifiedType) -> Bool in
+    switch tipe.baseType() {
     case let c as Control: c.name == "simple"
     default: false
     }
diff --git a/Tests/p4rseTests/ControlTests/Runtime.swift b/Tests/p4rseTests/ControlTests/Runtime.swift
index d861005..2b9afcb 100644
--- a/Tests/p4rseTests/ControlTests/Runtime.swift
+++ b/Tests/p4rseTests/ControlTests/Runtime.swift
@@ -53,24 +53,24 @@ import TreeSitterP4
   let program = try! #UseOkResult(Program.Compile(simple_parser_declaration))
 
   // Pull the control out of the compiled program.
-  let controls = program.InstancesWithTypes() { (tipe: P4Type) -> Bool in
-    switch tipe.dataType() {
+  let controls = program.InstancesWithTypes() { (tipe: P4QualifiedType) -> Bool in
+    switch tipe.baseType() {
     case let c as Control: c.name == "simple"
     default: false
     }
   }
-  var control = ((controls[0].dataType() as P4DataType) as! Control)
+  var control = ((controls[0].baseType() as P4DataType) as! Control)
 
   // Add entries to the table.
   control = control.updateTable(
     addEntry: (
       P4Value(P4BooleanValue(withValue: true)),
-      TypedIdentifier(name: "a", withType: P4Type(Action()))
+      TypedIdentifier(name: "a", withType: P4QualifiedType(Action()))
     )
   ).updateTable(
     addEntry: (
       P4Value(P4BooleanValue(withValue: false)),
-      TypedIdentifier(name: "b", withType: P4Type(Action()))
+      TypedIdentifier(name: "b", withType: P4QualifiedType(Action()))
     ))
 
   // Set a variable in the global scope for the inout first parameter.
@@ -79,14 +79,14 @@ import TreeSitterP4
     identifier: Identifier(name: "result_arg"),
     withValue: P4Value(
           P4IntValue(withValue: 0),
-          P4Type(P4Int())))
+          P4QualifiedType(P4Int())))
 
   let runtime = try #UseOkResult(
     P4Runtime.Runtime<P4TableHitMissValue, Control>.create(control: control, withGlobalValues: global_values))
 
   let (hit_miss, updated_execution) = try #UseOkResult(runtime.run(
     withArguments: ArgumentList([
-      Argument(TypedIdentifier(name: "result_arg", withType: P4Type(P4Int())), atIndex: 0),
+      Argument(TypedIdentifier(name: "result_arg", withType: P4QualifiedType(P4Int())), atIndex: 0),
       Argument(P4Value(P4BooleanValue(withValue: true)), atIndex: 1),
     ])))
 
@@ -124,24 +124,24 @@ import TreeSitterP4
   let program = try! #UseOkResult(Program.Compile(simple_parser_declaration))
 
   // Pull the control out of the compiled program.
-  let controls = program.InstancesWithTypes() { (tipe: P4Type) -> Bool in
-    switch tipe.dataType() {
+  let controls = program.InstancesWithTypes() { (tipe: P4QualifiedType) -> Bool in
+    switch tipe.baseType() {
     case let c as Control: c.name == "simple"
     default: false
     }
   }
-  var control = ((controls[0].dataType() as P4DataType) as! Control)
+  var control = ((controls[0].baseType() as P4DataType) as! Control)
 
   // Add entries to the table.
   control = control.updateTable(
     addEntry: (
       P4Value(P4BooleanValue(withValue: true)),
-      TypedIdentifier(name: "a", withType: P4Type(Action()))
+      TypedIdentifier(name: "a", withType: P4QualifiedType(Action()))
     )
   ).updateTable(
     addEntry: (
       P4Value(P4BooleanValue(withValue: false)),
-      TypedIdentifier(name: "b", withType: P4Type(Action()))
+      TypedIdentifier(name: "b", withType: P4QualifiedType(Action()))
     ))
 
   // Set a variable in the global scope for the inout first parameter.
@@ -150,14 +150,14 @@ import TreeSitterP4
     identifier: Identifier(name: "result_arg"),
     withValue: P4Value(
           P4IntValue(withValue: 0),
-          P4Type(P4Int())))
+          P4QualifiedType(P4Int())))
 
   let runtime = try #UseOkResult(
     P4Runtime.Runtime<P4TableHitMissValue, Control>.create(control: control, withGlobalValues: global_values))
 
   let (hit_miss, updated_execution) = try #UseOkResult(runtime.run(
     withArguments: ArgumentList([
-      Argument(TypedIdentifier(name: "result_arg", withType: P4Type(P4Int())), atIndex: 0),
+      Argument(TypedIdentifier(name: "result_arg", withType: P4QualifiedType(P4Int())), atIndex: 0),
       Argument(P4Value(P4BooleanValue(withValue: false)), atIndex: 1),
     ])))
 
@@ -195,24 +195,24 @@ import TreeSitterP4
   let program = try! #UseOkResult(Program.Compile(simple_parser_declaration))
 
   // Pull the control out of the compiled program.
-  let controls = program.InstancesWithTypes() { (tipe: P4Type) -> Bool in
-    switch tipe.dataType() {
+  let controls = program.InstancesWithTypes() { (tipe: P4QualifiedType) -> Bool in
+    switch tipe.baseType() {
     case let c as Control: c.name == "simple"
     default: false
     }
   }
-  var control = ((controls[0].dataType() as P4DataType) as! Control)
+  var control = ((controls[0].baseType() as P4DataType) as! Control)
 
   // Add entries to the table.
   control = control.updateTable(
     addEntry: (
       P4Value(P4IntValue(withValue: 5)),
-      TypedIdentifier(name: "a", withType: P4Type(Action()))
+      TypedIdentifier(name: "a", withType: P4QualifiedType(Action()))
     )
   ).updateTable(
     addEntry: (
       P4Value(P4IntValue(withValue: 2)),
-      TypedIdentifier(name: "b", withType: P4Type(Action()))
+      TypedIdentifier(name: "b", withType: P4QualifiedType(Action()))
     ))
 
   // Set a variable in the global scope for the inout first parameter.
@@ -221,14 +221,14 @@ import TreeSitterP4
     identifier: Identifier(name: "result_arg"),
     withValue: P4Value(
           P4IntValue(withValue: 0),
-          P4Type(P4Int())))
+          P4QualifiedType(P4Int())))
 
   let runtime = try #UseOkResult(
     P4Runtime.Runtime<P4TableHitMissValue, Control>.create(control: control, withGlobalValues: global_values))
 
   let (hit_miss, updated_execution) = try #UseOkResult(runtime.run(
     withArguments: ArgumentList([
-      Argument(TypedIdentifier(name: "result_arg", withType: P4Type(P4Int())), atIndex: 0),
+      Argument(TypedIdentifier(name: "result_arg", withType: P4QualifiedType(P4Int())), atIndex: 0),
       Argument(P4Value(P4IntValue(withValue: 5)), atIndex: 1),
     ])))
 
@@ -265,24 +265,24 @@ import TreeSitterP4
   let program = try! #UseOkResult(Program.Compile(simple_parser_declaration))
 
   // Pull the control out of the compiled program.
-  let controls = program.InstancesWithTypes() { (tipe: P4Type) -> Bool in
-    switch tipe.dataType() {
+  let controls = program.InstancesWithTypes() { (tipe: P4QualifiedType) -> Bool in
+    switch tipe.baseType() {
     case let c as Control: c.name == "simple"
     default: false
     }
   }
-  var control = ((controls[0].dataType() as P4DataType) as! Control)
+  var control = ((controls[0].baseType() as P4DataType) as! Control)
 
   // Add entries to the table.
   control = control.updateTable(
     addEntry: (
       P4Value(P4IntValue(withValue: 1)),
-      TypedIdentifier(name: "a", withType: P4Type(Action()))
+      TypedIdentifier(name: "a", withType: P4QualifiedType(Action()))
     )
   ).updateTable(
     addEntry: (
       P4Value(P4IntValue(withValue: 2)),
-      TypedIdentifier(name: "b", withType: P4Type(Action()))
+      TypedIdentifier(name: "b", withType: P4QualifiedType(Action()))
     ))
 
   // Set a variable in the global scope for the inout first parameter.
@@ -291,14 +291,14 @@ import TreeSitterP4
     identifier: Identifier(name: "result_arg"),
     withValue: P4Value(
           P4IntValue(withValue: 0),
-          P4Type(P4Int())))
+          P4QualifiedType(P4Int())))
 
   let runtime = try #UseOkResult(
     P4Runtime.Runtime<P4TableHitMissValue, Control>.create(control: control, withGlobalValues: global_values))
 
   let (hit_miss, updated_execution) = try #UseOkResult(runtime.run(
     withArguments: ArgumentList([
-      Argument(TypedIdentifier(name: "result_arg", withType: P4Type(P4Int())), atIndex: 0),
+      Argument(TypedIdentifier(name: "result_arg", withType: P4QualifiedType(P4Int())), atIndex: 0),
       Argument(P4Value(P4IntValue(withValue: 3)), atIndex: 1),
     ])))
 
@@ -336,24 +336,24 @@ import TreeSitterP4
   let program = try! #UseOkResult(Program.Compile(simple_parser_declaration))
 
   // Pull the control out of the compiled program.
-  let controls = program.InstancesWithTypes() { (tipe: P4Type) -> Bool in
-    switch tipe.dataType() {
+  let controls = program.InstancesWithTypes() { (tipe: P4QualifiedType) -> Bool in
+    switch tipe.baseType() {
     case let c as Control: c.name == "simple"
     default: false
     }
   }
-  var control = ((controls[0].dataType() as P4DataType) as! Control)
+  var control = ((controls[0].baseType() as P4DataType) as! Control)
 
   // Add entries to the table.
   control = control.updateTable(
     addEntry: (
       P4Value(P4BooleanValue(withValue: true)),
-      TypedIdentifier(name: "a", withType: P4Type(Action()))
+      TypedIdentifier(name: "a", withType: P4QualifiedType(Action()))
     )
   ).updateTable(
     addEntry: (
       P4Value(P4IntValue(withValue: 5)),
-      TypedIdentifier(name: "b", withType: P4Type(Action()))
+      TypedIdentifier(name: "b", withType: P4QualifiedType(Action()))
     ))
 
   // Set a variable in the global scope for the inout first parameter.
@@ -362,14 +362,14 @@ import TreeSitterP4
     identifier: Identifier(name: "result_arg"),
     withValue: P4Value(
           P4IntValue(withValue: 0),
-          P4Type(P4Int())))
+          P4QualifiedType(P4Int())))
 
   let runtime = try #UseOkResult(
     P4Runtime.Runtime<P4TableHitMissValue, Control>.create(control: control, withGlobalValues: global_values))
 
   let (hit_miss, updated_execution) = try #UseOkResult(runtime.run(
     withArguments: ArgumentList([
-      Argument(TypedIdentifier(name: "result_arg", withType: P4Type(P4Int())), atIndex: 0),
+      Argument(TypedIdentifier(name: "result_arg", withType: P4QualifiedType(P4Int())), atIndex: 0),
       Argument(P4Value(P4BooleanValue(withValue: false)), atIndex: 1),
       Argument(P4Value(P4IntValue(withValue: 5)), atIndex: 2),
     ])))
diff --git a/Tests/p4rseTests/ExternDeclarations.swift b/Tests/p4rseTests/ExternDeclarations.swift
index b883d7e..9830570 100644
--- a/Tests/p4rseTests/ExternDeclarations.swift
+++ b/Tests/p4rseTests/ExternDeclarations.swift
@@ -38,10 +38,10 @@ public struct Return5: P4FFI {
     return ParameterList()
   }
 
-  public func type() -> Common.P4Type {
-    return P4Type(
+  public func type() -> Common.P4QualifiedType {
+    return P4QualifiedType(
       FunctionDeclaration(
-        named: Identifier(name: "externally"), ofType: P4Type(P4Int()),
+        named: Identifier(name: "externally"), ofType: P4QualifiedType(P4Int()),
         withParameters: ParameterList(), withBody: .none?))
   }
 
@@ -59,10 +59,10 @@ public struct Return6: P4FFI {
     return ParameterList()
   }
 
-  public func type() -> Common.P4Type {
-    return P4Type(
+  public func type() -> Common.P4QualifiedType {
+    return P4QualifiedType(
       FunctionDeclaration(
-        named: Identifier(name: "externally"), ofType: P4Type(P4Int()),
+        named: Identifier(name: "externally"), ofType: P4QualifiedType(P4Int()),
         withParameters: ParameterList(), withBody: .none?))
   }
 
diff --git a/Tests/p4rseTests/ParserCompilerTests.swift b/Tests/p4rseTests/ParserCompilerTests.swift
index afbc00e..d9be3d3 100644
--- a/Tests/p4rseTests/ParserCompilerTests.swift
+++ b/Tests/p4rseTests/ParserCompilerTests.swift
@@ -118,7 +118,7 @@ import P4Lang
   #expect(parameters.parameters.count == 1)
 
   #expect(parameters.parameters[0].name == Identifier(name: "pmtr"))
-  #expect(parameters.parameters[0].type.dataType().eq(rhs: P4Boolean()))
+  #expect(parameters.parameters[0].type.baseType().eq(rhs: P4Boolean()))
 }
 
 @Test func test_simple_compiler_parser_with_multiple_parameters() async throws {
@@ -138,10 +138,10 @@ import P4Lang
   #expect(parameters.parameters.count == 2)
 
   #expect(parameters.parameters[0].name == Identifier(name: "pmtr"))
-  #expect(parameters.parameters[0].type.dataType().eq(rhs: P4Boolean()))
+  #expect(parameters.parameters[0].type.baseType().eq(rhs: P4Boolean()))
 
   #expect(parameters.parameters[1].name == Identifier(name: "smtr"))
-  #expect(parameters.parameters[1].type.dataType().eq(rhs: P4String()))
+  #expect(parameters.parameters[1].type.baseType().eq(rhs: P4String()))
 }
 
 @Test func test_simple_compiler_parser_with_multiple_parameters2() async throws {
@@ -161,13 +161,13 @@ import P4Lang
   #expect(parameters.parameters.count == 3)
 
   #expect(parameters.parameters[0].name == Identifier(name: "pmtr"))
-  #expect(parameters.parameters[0].type.dataType().eq(rhs: P4Boolean()))
+  #expect(parameters.parameters[0].type.baseType().eq(rhs: P4Boolean()))
 
   #expect(parameters.parameters[1].name == Identifier(name: "smtr"))
-  #expect(parameters.parameters[1].type.dataType().eq(rhs: P4String()))
+  #expect(parameters.parameters[1].type.baseType().eq(rhs: P4String()))
 
   #expect(parameters.parameters[2].name == Identifier(name: "imtr"))
-  #expect(parameters.parameters[2].type.dataType().eq(rhs: P4Int()))
+  #expect(parameters.parameters[2].type.baseType().eq(rhs: P4Int()))
 }
 
 @Test func test_simple_compiler_parser_use_parameters() async throws {
diff --git a/Tests/p4rseTests/ScopeTests.swift b/Tests/p4rseTests/ScopeTests.swift
index 48fc355..bca1c5b 100644
--- a/Tests/p4rseTests/ScopeTests.swift
+++ b/Tests/p4rseTests/ScopeTests.swift
@@ -28,39 +28,39 @@ import TreeSitterP4
 
 @Test func test_scope() async throws {
   let s = VarTypeScope()
-  let s2 = s.declare(identifier: Identifier(name: "first"), withValue: P4Type(P4Int()))
+  let s2 = s.declare(identifier: Identifier(name: "first"), withValue: P4QualifiedType(P4Int()))
   let found_first = try! #require(s2.lookup(identifier: Identifier(name: "first")))
 
-  #expect(found_first.dataType().eq(rhs: P4Int()))
+  #expect(found_first.baseType().eq(rhs: P4Int()))
   #expect(s2.count == 1)
 }
 
 @Test func test_scope_no_set() async throws {
   var ss = VarTypeScopes().enter()
-  ss = ss.declare(identifier: Identifier(name: "first"), withValue: P4Type(P4Int()))
+  ss = ss.declare(identifier: Identifier(name: "first"), withValue: P4QualifiedType(P4Int()))
   ss = ss.enter()
-  ss = ss.declare(identifier: Identifier(name: "second"), withValue: P4Type(P4Boolean()))
+  ss = ss.declare(identifier: Identifier(name: "second"), withValue: P4QualifiedType(P4Boolean()))
 
   let found_first = try! #UseOkResult(ss.lookup(identifier: Identifier(name: "first")))
   let found_second = try! #UseOkResult(ss.lookup(identifier: Identifier(name: "second")))
 
-  #expect(found_first.dataType().eq(rhs: P4Int()))
-  #expect(found_second.dataType().eq(rhs: P4Boolean()))
+  #expect(found_first.baseType().eq(rhs: P4Int()))
+  #expect(found_second.baseType().eq(rhs: P4Boolean()))
 }
 
 @Test func test_scope_set() async throws {
   var ss = VarTypeScopes().enter()
   let id = Identifier(name: "first")
-  let id_type = P4Type(P4Int())
+  let id_type = P4QualifiedType(P4Int())
 
   ss = ss.declare(identifier: id, withValue: id_type)
   ss = ss.enter()
-  ss = ss.declare(identifier: Identifier(name: "second"), withValue: P4Type(P4Boolean()))
+  ss = ss.declare(identifier: Identifier(name: "second"), withValue: P4QualifiedType(P4Boolean()))
   // Change the value of `first`.
-  ss = ss.set(identifier: id, withValue: P4Type(P4String()))
+  ss = ss.set(identifier: id, withValue: P4QualifiedType(P4String()))
 
   // Verify the change!
   let found = try! #UseOkResult(ss.lookup(identifier: id))
 
-  #expect(found.dataType().eq(rhs: P4String()))
+  #expect(found.baseType().eq(rhs: P4String()))
 }
diff --git a/Tests/p4rseTests/StructTests.swift b/Tests/p4rseTests/StructTests.swift
index 90451bc..5e2dd89 100644
--- a/Tests/p4rseTests/StructTests.swift
+++ b/Tests/p4rseTests/StructTests.swift
@@ -41,11 +41,11 @@ import TreeSitterP4
     """
   var test_declarations = VarTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4Type(struct_type))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4QualifiedType(struct_type))
 
   var test_values = VarValueScopes().enter()
   test_values = test_values.declare(
@@ -78,8 +78,8 @@ import TreeSitterP4
     """
   var test_types = TypeTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
   test_types = test_types.declare(identifier: Identifier(name: "Testing"), withValue: struct_type)
@@ -108,8 +108,8 @@ import TreeSitterP4
     """
   var test_types = TypeTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
   test_types = test_types.declare(identifier: Identifier(name: "Testing"), withValue: struct_type)
@@ -135,11 +135,11 @@ import TreeSitterP4
     """
   var test_declarations = VarTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4Type(struct_type))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4QualifiedType(struct_type))
 
   var test_values = VarValueScopes().enter()
   test_values = test_values.declare(
@@ -170,11 +170,11 @@ import TreeSitterP4
     """
   var test_declarations = VarTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4Type(struct_type))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4QualifiedType(struct_type))
 
   var test_values = VarValueScopes().enter()
   test_values = test_values.declare(
@@ -204,11 +204,11 @@ import TreeSitterP4
     """
   var test_declarations = VarTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4Type(struct_type))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4QualifiedType(struct_type))
 
   var test_values = VarValueScopes().enter()
   test_values = test_values.declare(
@@ -240,15 +240,15 @@ import TreeSitterP4
   var test_declarations = VarTypeScopes().enter()
 
   let ty_fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   let ty_struct_type = P4Struct(withName: Identifier(name: "nested"), andFields: ty_fields)
 
-  let ts_fields = P4StructFields([P4StructFieldIdentifier(name: "ty", withType: P4Type(ty_struct_type))])
+  let ts_fields = P4StructFields([P4StructFieldIdentifier(name: "ty", withType: P4QualifiedType(ty_struct_type))])
   let ts_struct_type = P4Struct(withName: Identifier(name: "outer"), andFields: ts_fields)
 
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4Type(ts_struct_type))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4QualifiedType(ts_struct_type))
 
   var test_values = VarValueScopes().enter()
 
@@ -286,11 +286,11 @@ import TreeSitterP4
     """
   var test_declarations = VarTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4Type(struct_type))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4QualifiedType(struct_type))
 
   var test_values = VarValueScopes().enter()
   test_values = test_values.declare(
@@ -318,11 +318,11 @@ import TreeSitterP4
     """
   var test_declarations = VarTypeScopes().enter()
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4Type(struct_type))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4QualifiedType(struct_type))
 
   #expect(
     #RequireErrorResult(
@@ -349,15 +349,15 @@ import TreeSitterP4
   var test_declarations = VarTypeScopes().enter()
 
   let ty_fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   let ty_struct_type = P4Struct(withName: Identifier(name: "nested"), andFields: ty_fields)
 
-  let ts_fields = P4StructFields([P4StructFieldIdentifier(name: "ty", withType: P4Type(ty_struct_type))])
+  let ts_fields = P4StructFields([P4StructFieldIdentifier(name: "ty", withType: P4QualifiedType(ty_struct_type))])
   let ts_struct_type = P4Struct(withName: Identifier(name: "outer"), andFields: ts_fields)
 
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4Type(ts_struct_type))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4QualifiedType(ts_struct_type))
 
   var test_values = VarValueScopes().enter()
 
@@ -397,15 +397,15 @@ import TreeSitterP4
   var test_declarations = VarTypeScopes().enter()
 
   let ty_fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   let ty_struct_type = P4Struct(withName: Identifier(name: "nested"), andFields: ty_fields)
 
-  let ts_fields = P4StructFields([P4StructFieldIdentifier(name: "ty", withType: P4Type(ty_struct_type))])
+  let ts_fields = P4StructFields([P4StructFieldIdentifier(name: "ty", withType: P4QualifiedType(ty_struct_type))])
   let ts_struct_type = P4Struct(withName: Identifier(name: "outer"), andFields: ts_fields)
 
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4Type(ts_struct_type))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4QualifiedType(ts_struct_type))
 
   var test_values = VarValueScopes().enter()
 
@@ -444,15 +444,15 @@ import TreeSitterP4
   var test_declarations = VarTypeScopes().enter()
 
   let ty_fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
   let ty_struct_type = P4Struct(withName: Identifier(name: "nested"), andFields: ty_fields)
 
-  let ts_fields = P4StructFields([P4StructFieldIdentifier(name: "ty", withType: P4Type(ty_struct_type))])
+  let ts_fields = P4StructFields([P4StructFieldIdentifier(name: "ty", withType: P4QualifiedType(ty_struct_type))])
   let ts_struct_type = P4Struct(withName: Identifier(name: "outer"), andFields: ts_fields)
 
-  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4Type(ts_struct_type))
+  test_declarations = test_declarations.declare(identifier: Identifier(name: "ts"), withValue: P4QualifiedType(ts_struct_type))
 
   #expect(
     #RequireErrorResult(
diff --git a/Tests/p4rseTests/TypeTests.swift b/Tests/p4rseTests/TypeTests.swift
index 1eab21f..e07ad34 100644
--- a/Tests/p4rseTests/TypeTests.swift
+++ b/Tests/p4rseTests/TypeTests.swift
@@ -26,8 +26,8 @@ import TreeSitterP4
 
 @Test func test_simple_struct() async throws {
   let fields = P4StructFields([
-    P4StructFieldIdentifier(name: "yesno", withType: P4Type(P4Boolean())),
-    P4StructFieldIdentifier(name: "count", withType: P4Type(P4Int())),
+    P4StructFieldIdentifier(name: "yesno", withType: P4QualifiedType(P4Boolean())),
+    P4StructFieldIdentifier(name: "count", withType: P4QualifiedType(P4Int())),
   ])
 
   let struct_type = P4Struct(withName: Identifier(name: "Testing"), andFields: fields)
diff --git a/Tests/p4rseTests/ValueTypeParserTests.swift b/Tests/p4rseTests/ValueTypeParserTests.swift
index dd6364f..cd8dbae 100644
--- a/Tests/p4rseTests/ValueTypeParserTests.swift
+++ b/Tests/p4rseTests/ValueTypeParserTests.swift
@@ -253,7 +253,7 @@ import TreeSitterP4
       };
     """
   var test_types = VarTypeScopes().enter()
-  test_types = test_types.declare(identifier: Identifier(name: "ta"), withValue: P4Type(P4Array(withValueType: P4Type(P4Int()))))
+  test_types = test_types.declare(identifier: Identifier(name: "ta"), withValue: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Int()))))
   #expect(
     #RequireErrorResult(
       Error(