Introduce Type interface

30 files changed, 196 insertions, 128 deletions

diff --git a/src/main/java/org/zwobble/couscous/ast/AnnotationNode.java b/src/main/java/org/zwobble/couscous/ast/AnnotationNode.java
index e102af7..b70ed12 100644
--- a/src/main/java/org/zwobble/couscous/ast/AnnotationNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/AnnotationNode.java
@@ -1,20 +1,21 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.NodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
 public class AnnotationNode implements Node {
-    public static AnnotationNode annotation(TypeName type) {
+    public static AnnotationNode annotation(Type type) {
         return new AnnotationNode(type);
     }
     
-    private final TypeName type;
+    private final Type type;
     
-    private AnnotationNode(TypeName type) {
+    private AnnotationNode(Type type) {
         this.type = type;
     }
     
-    public TypeName getType() {
+    public Type getType() {
         return type;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/AssignmentNode.java b/src/main/java/org/zwobble/couscous/ast/AssignmentNode.java
index ec781b3..64fb973 100644
--- a/src/main/java/org/zwobble/couscous/ast/AssignmentNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/AssignmentNode.java
@@ -1,5 +1,6 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
@@ -52,7 +53,7 @@ public class AssignmentNode implements ExpressionNode {
     }
 
     @Override
-    public TypeName getType() {
+    public Type getType() {
         return value.getType();
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/CastNode.java b/src/main/java/org/zwobble/couscous/ast/CastNode.java
index 20ae9c6..75201e7 100644
--- a/src/main/java/org/zwobble/couscous/ast/CastNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/CastNode.java
@@ -1,17 +1,18 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
 public class CastNode implements ExpressionNode {
-    public static ExpressionNode cast(ExpressionNode expression, TypeName type) {
+    public static ExpressionNode cast(ExpressionNode expression, Type type) {
         return new CastNode(expression, type);
     }
 
     private final ExpressionNode expression;
-    private final TypeName type;
+    private final Type type;
 
-    private CastNode(ExpressionNode expression, TypeName type) {
+    private CastNode(ExpressionNode expression, Type type) {
         this.expression = expression;
         this.type = type;
     }
@@ -21,7 +22,7 @@ public class CastNode implements ExpressionNode {
     }
 
     @Override
-    public TypeName getType() {
+    public Type getType() {
         return type;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/ClassNode.java b/src/main/java/org/zwobble/couscous/ast/ClassNode.java
index 2342315..d50051c 100644
--- a/src/main/java/org/zwobble/couscous/ast/ClassNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/ClassNode.java
@@ -1,5 +1,7 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.ScalarType;
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.NodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
@@ -7,7 +9,7 @@ import java.util.List;
 import java.util.Set;
 
 public class ClassNode implements TypeNode {
-    public static ClassNodeBuilder builder(TypeName name) {
+    public static ClassNodeBuilder builder(ScalarType name) {
         return new ClassNodeBuilder(name);
     }
     public static ClassNodeBuilder builder(String name) {
@@ -15,9 +17,9 @@ public class ClassNode implements TypeNode {
     }
 
     public static ClassNode declareClass(
-        TypeName name,
+        ScalarType name,
         List<FormalTypeParameterNode> typeParameters,
-        Set<TypeName> superTypes,
+        Set<Type> superTypes,
         List<FieldDeclarationNode> fields,
         List<StatementNode> staticConstructor,
         ConstructorNode constructor,
@@ -26,18 +28,18 @@ public class ClassNode implements TypeNode {
         return new ClassNode(name, typeParameters, superTypes, fields, staticConstructor, constructor, methods);
     }
     
-    private final TypeName name;
+    private final ScalarType name;
     private final List<FormalTypeParameterNode> typeParameters;
-    private final Set<TypeName> superTypes;
+    private final Set<Type> superTypes;
     private final List<FieldDeclarationNode> fields;
     private final List<StatementNode> staticConstructor;
     private final ConstructorNode constructor;
     private final List<MethodNode> methods;
     
     public ClassNode(
-        TypeName name,
+        ScalarType name,
         List<FormalTypeParameterNode> typeParameters,
-        Set<TypeName> superTypes,
+        Set<Type> superTypes,
         List<FieldDeclarationNode> fields,
         List<StatementNode> staticConstructor,
         ConstructorNode constructor,
@@ -53,7 +55,7 @@ public class ClassNode implements TypeNode {
     }
 
     @Override
-    public TypeName getName() {
+    public ScalarType getName() {
         return name;
     }
 
@@ -63,7 +65,7 @@ public class ClassNode implements TypeNode {
     }
 
     @Override
-    public Set<TypeName> getSuperTypes() {
+    public Set<Type> getSuperTypes() {
         return superTypes;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/ClassNodeBuilder.java b/src/main/java/org/zwobble/couscous/ast/ClassNodeBuilder.java
index 282df33..9dc5098 100644
--- a/src/main/java/org/zwobble/couscous/ast/ClassNodeBuilder.java
+++ b/src/main/java/org/zwobble/couscous/ast/ClassNodeBuilder.java
@@ -3,6 +3,8 @@ package org.zwobble.couscous.ast;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import org.zwobble.couscous.ast.identifiers.Identifier;
+import org.zwobble.couscous.ast.types.ScalarType;
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.values.UnitValue;
 
 import java.util.List;
@@ -15,15 +17,15 @@ import static org.zwobble.couscous.ast.VariableDeclaration.var;
 import static org.zwobble.couscous.util.ExtraLists.list;
 
 public class ClassNodeBuilder {
-    private final TypeName name;
-    private final ImmutableSet.Builder<TypeName> superTypes;
+    private final ScalarType name;
+    private final ImmutableSet.Builder<Type> superTypes;
     private final ImmutableList.Builder<FormalTypeParameterNode> typeParameters;
     private final ImmutableList.Builder<FieldDeclarationNode> fields;
     private List<StatementNode> staticConstructor;
     private Optional<ConstructorNode> constructor;
     private final ImmutableList.Builder<MethodNode> methods;
 
-    public ClassNodeBuilder(TypeName name) {
+    public ClassNodeBuilder(ScalarType name) {
         this.name = name;
         this.typeParameters = ImmutableList.builder();
         this.superTypes = ImmutableSet.builder();
@@ -34,7 +36,7 @@ public class ClassNodeBuilder {
     }
 
     public ClassNodeBuilder(String name) {
-        this(TypeName.of(name));
+        this(ScalarType.of(name));
     }
 
     public ClassNodeBuilder addTypeParameter(String name) {
@@ -43,15 +45,15 @@ public class ClassNodeBuilder {
     }
 
     public ClassNodeBuilder addSuperType(String type) {
-        this.superTypes.add(TypeName.of(type));
+        this.superTypes.add(ScalarType.of(type));
         return this;
     }
 
-    public ClassNodeBuilder staticField(String name, TypeName type) {
+    public ClassNodeBuilder staticField(String name, ScalarType type) {
         return field(FieldDeclarationNode.staticField(name, type));
     }
 
-    public ClassNodeBuilder field(String name, TypeName type) {
+    public ClassNodeBuilder field(String name, ScalarType type) {
         return field(FieldDeclarationNode.field(name, type));
     }
 
@@ -132,7 +134,7 @@ public class ClassNodeBuilder {
         private final Function<MethodBuilder<?>, T> build;
         private final ImmutableList.Builder<AnnotationNode> annotations;
         private final ImmutableList.Builder<FormalArgumentNode> arguments;
-        private TypeName returnType = UnitValue.REF;
+        private ScalarType returnType = UnitValue.REF;
         private final ImmutableList.Builder<StatementNode> statements;
 
         public MethodBuilder(Function<MethodBuilder<?>, T> build) {
@@ -142,7 +144,7 @@ public class ClassNodeBuilder {
             this.statements = ImmutableList.builder();
         }
         
-        public MethodBuilder<T> annotation(TypeName type) {
+        public MethodBuilder<T> annotation(ScalarType type) {
             annotations.add(AnnotationNode.annotation(type));
             return this;
         }
@@ -151,12 +153,12 @@ public class ClassNodeBuilder {
             return ThisReferenceNode.thisReference(name);
         }
         
-        public MethodBuilder<T> argument(Identifier id, String name, TypeName type) {
+        public MethodBuilder<T> argument(Identifier id, String name, ScalarType type) {
             arguments.add(formalArg(var(id, name, type)));
             return this;
         }
 
-        public MethodBuilder<T> returns(TypeName returnType) {
+        public MethodBuilder<T> returns(ScalarType returnType) {
             this.returnType = returnType;
             return this;
         }
diff --git a/src/main/java/org/zwobble/couscous/ast/ConstructorCallNode.java b/src/main/java/org/zwobble/couscous/ast/ConstructorCallNode.java
index b5439bf..5a597d1 100644
--- a/src/main/java/org/zwobble/couscous/ast/ConstructorCallNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/ConstructorCallNode.java
@@ -1,5 +1,6 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
@@ -7,23 +8,25 @@ import java.util.List;
 
 public class ConstructorCallNode implements ExpressionNode {
     public static ConstructorCallNode constructorCall(
-            TypeName type,
-            List<? extends ExpressionNode> arguments) {
+        Type type,
+        List<? extends ExpressionNode> arguments)
+    {
         return new ConstructorCallNode(type, arguments);
     }
     
-    private final TypeName type;
+    private final Type type;
     private final List<? extends ExpressionNode> arguments;
     
     public ConstructorCallNode(
-            TypeName type,
-            List<? extends ExpressionNode> arguments) {
+        Type type,
+        List<? extends ExpressionNode> arguments)
+    {
         this.type = type;
         this.arguments = arguments;
     }
     
     @Override
-    public TypeName getType() {
+    public Type getType() {
         return type;
     }
     
diff --git a/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java b/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java
index a7842d3..2452183 100644
--- a/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java
@@ -1,11 +1,12 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
 public interface ExpressionNode extends Node {
-    TypeName getType();
+    Type getType();
     <T> T accept(ExpressionNodeMapper<T> visitor);
     
     @Override
diff --git a/src/main/java/org/zwobble/couscous/ast/FieldAccessNode.java b/src/main/java/org/zwobble/couscous/ast/FieldAccessNode.java
index a949630..e417638 100644
--- a/src/main/java/org/zwobble/couscous/ast/FieldAccessNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/FieldAccessNode.java
@@ -1,5 +1,7 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.ScalarType;
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.AssignableExpressionNodeVisitor;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
@@ -11,15 +13,15 @@ public class FieldAccessNode implements AssignableExpressionNode {
     public static FieldAccessNode fieldAccess(
             ExpressionNode left,
             String fieldName,
-            TypeName type)
+            Type type)
     {
         return fieldAccess(instanceReceiver(left), fieldName, type);
     }
 
     public static FieldAccessNode fieldAccess(
-        TypeName left,
+        ScalarType left,
         String fieldName,
-        TypeName type)
+        Type type)
     {
         return fieldAccess(staticReceiver(left), fieldName, type);
     }
@@ -27,19 +29,19 @@ public class FieldAccessNode implements AssignableExpressionNode {
     public static FieldAccessNode fieldAccess(
         Receiver left,
         String fieldName,
-        TypeName type)
+        Type type)
     {
         return new FieldAccessNode(left, fieldName, type);
     }
     
     private final Receiver left;
     private final String fieldName;
-    private final TypeName type;
+    private final Type type;
     
     public FieldAccessNode(
         Receiver left,
         String fieldName,
-        TypeName type)
+        Type type)
     {
         this.left = left;
         this.fieldName = fieldName;
@@ -54,7 +56,7 @@ public class FieldAccessNode implements AssignableExpressionNode {
         return fieldName;
     }
     
-    public TypeName getType() {
+    public Type getType() {
         return type;
     }
     
diff --git a/src/main/java/org/zwobble/couscous/ast/FieldDeclarationNode.java b/src/main/java/org/zwobble/couscous/ast/FieldDeclarationNode.java
index a9f9b76..a207b82 100644
--- a/src/main/java/org/zwobble/couscous/ast/FieldDeclarationNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/FieldDeclarationNode.java
@@ -1,26 +1,27 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.NodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
 public class FieldDeclarationNode implements Node {
-    public static FieldDeclarationNode field(String name, TypeName type) {
+    public static FieldDeclarationNode field(String name, Type type) {
         return field(false, name, type);
     }
 
-    public static FieldDeclarationNode staticField(String name, TypeName type) {
+    public static FieldDeclarationNode staticField(String name, Type type) {
         return field(true, name, type);
     }
 
-    public static FieldDeclarationNode field(boolean isStatic, String name, TypeName type) {
+    public static FieldDeclarationNode field(boolean isStatic, String name, Type type) {
         return new FieldDeclarationNode(isStatic, name, type);
     }
 
     private final boolean isStatic;
     private final String name;
-    private final TypeName type;
+    private final Type type;
     
-    private FieldDeclarationNode(boolean isStatic, String name, TypeName type) {
+    private FieldDeclarationNode(boolean isStatic, String name, Type type) {
         this.isStatic = isStatic;
         this.name = name;
         this.type = type;
@@ -34,7 +35,7 @@ public class FieldDeclarationNode implements Node {
         return name;
     }
     
-    public TypeName getType() {
+    public Type getType() {
         return type;
     }
 
@@ -45,7 +46,8 @@ public class FieldDeclarationNode implements Node {
 
     public FieldDeclarationNode transform(NodeTransformer transformer) {
         return new FieldDeclarationNode(
-            isStatic, name,
+            isStatic,
+            name,
             transformer.transform(type));
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/FormalArgumentNode.java b/src/main/java/org/zwobble/couscous/ast/FormalArgumentNode.java
index f7d7f42..7df3ead 100644
--- a/src/main/java/org/zwobble/couscous/ast/FormalArgumentNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/FormalArgumentNode.java
@@ -1,5 +1,6 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.NodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
@@ -18,7 +19,7 @@ public class FormalArgumentNode implements VariableNode, Node {
         return declaration;
     }
     
-    public TypeName getType() {
+    public Type getType() {
         return declaration.getType();
     }
     
diff --git a/src/main/java/org/zwobble/couscous/ast/InterfaceNode.java b/src/main/java/org/zwobble/couscous/ast/InterfaceNode.java
index e5b876d..97faae4 100644
--- a/src/main/java/org/zwobble/couscous/ast/InterfaceNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/InterfaceNode.java
@@ -1,5 +1,7 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.ScalarType;
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.NodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
@@ -8,23 +10,23 @@ import java.util.Set;
 
 public class InterfaceNode implements TypeNode {
     public static InterfaceNode declareInterface(
-        TypeName name,
+        ScalarType name,
         List<FormalTypeParameterNode> typeParameters,
-        Set<TypeName> superTypes,
+        Set<Type> superTypes,
         List<MethodNode> methods)
     {
         return new InterfaceNode(name, typeParameters, superTypes, methods);
     }
 
-    private final TypeName name;
+    private final ScalarType name;
     private final List<FormalTypeParameterNode> typeParameters;
-    private final Set<TypeName> superTypes;
+    private final Set<Type> superTypes;
     private final List<MethodNode> methods;
 
     private InterfaceNode(
-        TypeName name,
+        ScalarType name,
         List<FormalTypeParameterNode> typeParameters,
-        Set<TypeName> superTypes,
+        Set<Type> superTypes,
         List<MethodNode> methodNodes)
     {
         this.name = name;
@@ -34,7 +36,7 @@ public class InterfaceNode implements TypeNode {
     }
 
     @Override
-    public TypeName getName() {
+    public ScalarType getName() {
         return name;
     }
 
@@ -44,7 +46,7 @@ public class InterfaceNode implements TypeNode {
     }
 
     @Override
-    public Set<TypeName> getSuperTypes() {
+    public Set<Type> getSuperTypes() {
         return superTypes;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/LiteralNode.java b/src/main/java/org/zwobble/couscous/ast/LiteralNode.java
index a76ca80..bb38562 100644
--- a/src/main/java/org/zwobble/couscous/ast/LiteralNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/LiteralNode.java
@@ -1,5 +1,6 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.ScalarType;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 import org.zwobble.couscous.values.*;
@@ -25,23 +26,23 @@ public class LiteralNode implements ExpressionNode {
         return new LiteralNode(value(value), BooleanValue.REF);
     }
 
-    public static LiteralNode literal(TypeName type) {
+    public static LiteralNode literal(ScalarType type) {
         return new LiteralNode(value(type), ObjectValues.CLASS);
     }
     
-    public static LiteralNode of(PrimitiveValue value, TypeName type) {
+    public static LiteralNode of(PrimitiveValue value, ScalarType type) {
         return new LiteralNode(value, type);
     }
     
     private final PrimitiveValue value;
-    private final TypeName type;
+    private final ScalarType type;
 
-    private LiteralNode(PrimitiveValue value, TypeName type) {
+    private LiteralNode(PrimitiveValue value, ScalarType type) {
         this.value = value;
         this.type = type;
     }
     
-    public TypeName getType() {
+    public ScalarType getType() {
         return type;
     }
     
diff --git a/src/main/java/org/zwobble/couscous/ast/LocalVariableDeclarationNode.java b/src/main/java/org/zwobble/couscous/ast/LocalVariableDeclarationNode.java
index 03e4226..5b571d0 100644
--- a/src/main/java/org/zwobble/couscous/ast/LocalVariableDeclarationNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/LocalVariableDeclarationNode.java
@@ -1,6 +1,7 @@
 package org.zwobble.couscous.ast;
 
 import org.zwobble.couscous.ast.identifiers.Identifier;
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 import org.zwobble.couscous.ast.visitors.StatementNodeMapper;
 
@@ -10,7 +11,7 @@ public class LocalVariableDeclarationNode implements VariableNode, StatementNode
     public static LocalVariableDeclarationNode localVariableDeclaration(
             Identifier id,
             String name,
-            TypeName type,
+            Type type,
             ExpressionNode initialValue) {
         return localVariableDeclaration(var(id, name, type), initialValue);
     }
@@ -43,7 +44,7 @@ public class LocalVariableDeclarationNode implements VariableNode, StatementNode
         return declaration.getName();
     }
     
-    public TypeName getType() {
+    public Type getType() {
         return declaration.getType();
     }
     
diff --git a/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java b/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java
index c4e0321..43993b8 100644
--- a/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java
@@ -1,5 +1,7 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.ScalarType;
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
@@ -14,15 +16,15 @@ public class MethodCallNode implements ExpressionNode {
         String className,
         String methodName,
         List<ExpressionNode> arguments,
-        TypeName type) {
-        return staticMethodCall(TypeName.of(className), methodName, arguments, type);
+        Type type) {
+        return staticMethodCall(ScalarType.of(className), methodName, arguments, type);
     }
 
     public static ExpressionNode staticMethodCall(
-        TypeName className,
+        ScalarType className,
         String methodName,
         List<ExpressionNode> arguments,
-        TypeName type) {
+        Type type) {
         return MethodCallNode.methodCall(staticReceiver(className), methodName, arguments, type);
     }
 
@@ -30,7 +32,7 @@ public class MethodCallNode implements ExpressionNode {
         ExpressionNode receiver,
         String methodName,
         List<ExpressionNode> arguments,
-        TypeName type)
+        Type type)
     {
         return methodCall(instanceReceiver(receiver), methodName, arguments, type);
     }
@@ -39,7 +41,7 @@ public class MethodCallNode implements ExpressionNode {
         Receiver receiver,
         String methodName,
         List<ExpressionNode> arguments,
-        TypeName type)
+        Type type)
     {
         return new MethodCallNode(receiver, methodName, arguments, type);
     }
@@ -47,13 +49,13 @@ public class MethodCallNode implements ExpressionNode {
     private final Receiver receiver;
     private final String methodName;
     private final List<ExpressionNode> arguments;
-    private final TypeName type;
+    private final Type type;
     
     private MethodCallNode(
         Receiver receiver,
         String methodName,
         List<ExpressionNode> arguments,
-        TypeName type)
+        Type type)
     {
         this.receiver = receiver;
         this.methodName = methodName;
@@ -73,7 +75,7 @@ public class MethodCallNode implements ExpressionNode {
         return arguments;
     }
     
-    public TypeName getType() {
+    public Type getType() {
         return type;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/MethodNode.java b/src/main/java/org/zwobble/couscous/ast/MethodNode.java
index 4909093..8589eb1 100644
--- a/src/main/java/org/zwobble/couscous/ast/MethodNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/MethodNode.java
@@ -1,6 +1,7 @@
 package org.zwobble.couscous.ast;
 
 import com.google.common.collect.ImmutableList;
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.NodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 import org.zwobble.couscous.values.UnitValue;
@@ -27,7 +28,7 @@ public class MethodNode implements Node {
         private final String name;
         private final ImmutableList.Builder<FormalArgumentNode> arguments =
             ImmutableList.builder();
-        private TypeName returnType = UnitValue.REF;
+        private Type returnType = UnitValue.REF;
         private final ImmutableList.Builder<StatementNode> body =
             ImmutableList.builder();
         
@@ -60,7 +61,7 @@ public class MethodNode implements Node {
             return this;
         }
 
-        public Builder returns(TypeName returnType) {
+        public Builder returns(Type returnType) {
             this.returnType = returnType;
             return this;
         }
@@ -91,7 +92,7 @@ public class MethodNode implements Node {
         boolean isStatic,
         String name,
         List<FormalArgumentNode> arguments,
-        TypeName returnType,
+        Type returnType,
         Optional<List<StatementNode>> body)
     {
         return new MethodNode(annotations, isStatic, name, arguments, returnType, body);
@@ -101,7 +102,7 @@ public class MethodNode implements Node {
     private final boolean isStatic;
     private final String name;
     private final List<FormalArgumentNode> arguments;
-    private final TypeName returnType;
+    private final Type returnType;
     private final Optional<List<StatementNode>> body;
     
     private MethodNode(
@@ -109,7 +110,7 @@ public class MethodNode implements Node {
         boolean isStatic,
         String name,
         List<FormalArgumentNode> arguments,
-        TypeName returnType,
+        Type returnType,
         Optional<List<StatementNode>> body)
     {
         this.annotations = annotations;
@@ -136,7 +137,7 @@ public class MethodNode implements Node {
         return arguments;
     }
 
-    public TypeName getReturnType() {
+    public Type getReturnType() {
         return returnType;
     }
     
diff --git a/src/main/java/org/zwobble/couscous/ast/MethodSignature.java b/src/main/java/org/zwobble/couscous/ast/MethodSignature.java
index 908e673..93d4f58 100644
--- a/src/main/java/org/zwobble/couscous/ast/MethodSignature.java
+++ b/src/main/java/org/zwobble/couscous/ast/MethodSignature.java
@@ -1,13 +1,15 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.Type;
+
 import java.util.List;
 
 public class MethodSignature {
     private final String name;
-    private final List<TypeName> arguments;
-    private final TypeName returnType;
+    private final List<Type> arguments;
+    private final Type returnType;
 
-    public MethodSignature(String name, List<TypeName> arguments, TypeName returnType) {
+    public MethodSignature(String name, List<Type> arguments, Type returnType) {
         this.name = name;
         this.arguments = arguments;
         this.returnType = returnType;
@@ -17,11 +19,11 @@ public class MethodSignature {
         return name;
     }
 
-    public List<TypeName> getArguments() {
+    public List<Type> getArguments() {
         return arguments;
     }
 
-    public TypeName getReturnType() {
+    public Type getReturnType() {
         return returnType;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/OperationNode.java b/src/main/java/org/zwobble/couscous/ast/OperationNode.java
index 4348c33..d6453e3 100644
--- a/src/main/java/org/zwobble/couscous/ast/OperationNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/OperationNode.java
@@ -1,20 +1,21 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
 import java.util.List;
 
 public class OperationNode implements ExpressionNode {
-    public static OperationNode operation(Operator operator, List<ExpressionNode> arguments, TypeName type) {
+    public static OperationNode operation(Operator operator, List<ExpressionNode> arguments, Type type) {
         return new OperationNode(operator, arguments, type);
     }
 
     private final Operator operator;
     private final List<ExpressionNode> arguments;
-    private TypeName type;
+    private Type type;
 
-    OperationNode(Operator operator, List<ExpressionNode> arguments, TypeName type) {
+    OperationNode(Operator operator, List<ExpressionNode> arguments, Type type) {
         this.operator = operator;
         this.arguments = arguments;
         this.type = type;
@@ -41,7 +42,7 @@ public class OperationNode implements ExpressionNode {
     }
 
     @Override
-    public TypeName getType() {
+    public Type getType() {
         return type;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/Receiver.java b/src/main/java/org/zwobble/couscous/ast/Receiver.java
index 1afb9b7..90395d2 100644
--- a/src/main/java/org/zwobble/couscous/ast/Receiver.java
+++ b/src/main/java/org/zwobble/couscous/ast/Receiver.java
@@ -1,5 +1,6 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.ScalarType;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
 public interface Receiver extends Node {
@@ -8,6 +9,6 @@ public interface Receiver extends Node {
 
     interface Mapper<T> {
         T visit(ExpressionNode receiver);
-        T visit(TypeName receiver);
+        T visit(ScalarType receiver);
     }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/StaticReceiver.java b/src/main/java/org/zwobble/couscous/ast/StaticReceiver.java
index 84cf266..3c6e32c 100644
--- a/src/main/java/org/zwobble/couscous/ast/StaticReceiver.java
+++ b/src/main/java/org/zwobble/couscous/ast/StaticReceiver.java
@@ -1,20 +1,21 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.ScalarType;
 import org.zwobble.couscous.ast.visitors.NodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
 public class StaticReceiver implements Receiver {
-    public static Receiver staticReceiver(TypeName type) {
+    public static Receiver staticReceiver(ScalarType type) {
         return new StaticReceiver(type);
     }
 
-    private final TypeName type;
+    private final ScalarType type;
 
-    public StaticReceiver(TypeName type) {
+    public StaticReceiver(ScalarType type) {
         this.type = type;
     }
 
-    public TypeName getType() {
+    public ScalarType getType() {
         return type;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/TernaryConditionalNode.java b/src/main/java/org/zwobble/couscous/ast/TernaryConditionalNode.java
index 3caec58..2d46473 100644
--- a/src/main/java/org/zwobble/couscous/ast/TernaryConditionalNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/TernaryConditionalNode.java
@@ -1,5 +1,6 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
@@ -50,7 +51,7 @@ public class TernaryConditionalNode implements ExpressionNode {
     }
 
     @Override
-    public TypeName getType() {
+    public Type getType() {
         return ifTrue.getType();
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/ThisReferenceNode.java b/src/main/java/org/zwobble/couscous/ast/ThisReferenceNode.java
index ebc2d8d..cdf995b 100644
--- a/src/main/java/org/zwobble/couscous/ast/ThisReferenceNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/ThisReferenceNode.java
@@ -1,20 +1,21 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
 public class ThisReferenceNode implements ExpressionNode, ReferenceNode {
-    public static ThisReferenceNode thisReference(TypeName type) {
+    public static ThisReferenceNode thisReference(Type type) {
         return new ThisReferenceNode(type);
     }
     
-    private final TypeName type;
+    private final Type type;
 
-    private ThisReferenceNode(TypeName type) {
+    private ThisReferenceNode(Type type) {
         this.type = type;
     }
     
-    public TypeName getType() {
+    public Type getType() {
         return type;
     }
     
diff --git a/src/main/java/org/zwobble/couscous/ast/TypeCoercionNode.java b/src/main/java/org/zwobble/couscous/ast/TypeCoercionNode.java
index 680ecea..c8c2a33 100644
--- a/src/main/java/org/zwobble/couscous/ast/TypeCoercionNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/TypeCoercionNode.java
@@ -1,17 +1,19 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.ScalarType;
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
 public class TypeCoercionNode implements ExpressionNode {
-    public static TypeCoercionNode typeCoercion(ExpressionNode expression, TypeName type) {
+    public static TypeCoercionNode typeCoercion(ExpressionNode expression, Type type) {
         return new TypeCoercionNode(expression, type);
     }
 
     private final ExpressionNode expression;
-    private final TypeName type;
+    private final Type type;
 
-    private TypeCoercionNode(ExpressionNode expression, TypeName type) {
+    private TypeCoercionNode(ExpressionNode expression, Type type) {
         this.expression = expression;
         this.type = type;
     }
@@ -21,7 +23,7 @@ public class TypeCoercionNode implements ExpressionNode {
     }
 
     @Override
-    public TypeName getType() {
+    public Type getType() {
         return type;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/TypeNode.java b/src/main/java/org/zwobble/couscous/ast/TypeNode.java
index e3a78af..af4ab81 100644
--- a/src/main/java/org/zwobble/couscous/ast/TypeNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/TypeNode.java
@@ -1,14 +1,16 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.types.ScalarType;
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 
 import java.util.List;
 import java.util.Set;
 
 public interface TypeNode extends Node {
-    TypeName getName();
+    ScalarType getName();
     List<FormalTypeParameterNode> getTypeParameters();
-    Set<TypeName> getSuperTypes();
+    Set<Type> getSuperTypes();
     List<MethodNode> getMethods();
     TypeNode transform(NodeTransformer transformer);
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/VariableDeclaration.java b/src/main/java/org/zwobble/couscous/ast/VariableDeclaration.java
index 5932371..55d4efb 100644
--- a/src/main/java/org/zwobble/couscous/ast/VariableDeclaration.java
+++ b/src/main/java/org/zwobble/couscous/ast/VariableDeclaration.java
@@ -1,17 +1,18 @@
 package org.zwobble.couscous.ast;
 
 import org.zwobble.couscous.ast.identifiers.Identifier;
+import org.zwobble.couscous.ast.types.Type;
 
 public class VariableDeclaration {
-    public static VariableDeclaration var(Identifier id, String name, TypeName type) {
+    public static VariableDeclaration var(Identifier id, String name, Type type) {
         return new VariableDeclaration(id, name, type);
     }
     
     private final Identifier id;
     private final String name;
-    private final TypeName type;
+    private final Type type;
     
-    private VariableDeclaration(Identifier id, String name, TypeName type) {
+    private VariableDeclaration(Identifier id, String name, Type type) {
         this.id = id;
         this.name = name;
         this.type = type;
@@ -25,7 +26,7 @@ public class VariableDeclaration {
         return name;
     }
     
-    public TypeName getType() {
+    public Type getType() {
         return type;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/VariableReferenceNode.java b/src/main/java/org/zwobble/couscous/ast/VariableReferenceNode.java
index f9800a5..2b81fbb 100644
--- a/src/main/java/org/zwobble/couscous/ast/VariableReferenceNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/VariableReferenceNode.java
@@ -1,6 +1,7 @@
 package org.zwobble.couscous.ast;
 
 import org.zwobble.couscous.ast.identifiers.Identifier;
+import org.zwobble.couscous.ast.types.Type;
 import org.zwobble.couscous.ast.visitors.AssignableExpressionNodeVisitor;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
@@ -34,7 +35,7 @@ public class VariableReferenceNode implements AssignableExpressionNode, Referenc
     }
 
     @Override
-    public TypeName getType() {
+    public Type getType() {
         return referent.getType();
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/sugar/AnonymousClass.java b/src/main/java/org/zwobble/couscous/ast/sugar/AnonymousClass.java
index fea72be..f8a8c48 100644
--- a/src/main/java/org/zwobble/couscous/ast/sugar/AnonymousClass.java
+++ b/src/main/java/org/zwobble/couscous/ast/sugar/AnonymousClass.java
@@ -2,18 +2,18 @@ package org.zwobble.couscous.ast.sugar;
 
 import org.zwobble.couscous.ast.FieldDeclarationNode;
 import org.zwobble.couscous.ast.MethodNode;
-import org.zwobble.couscous.ast.TypeName;
+import org.zwobble.couscous.ast.types.Type;
 
 import java.util.List;
 import java.util.Set;
 
 public class AnonymousClass {
-    private final Set<TypeName> superTypes;
+    private final Set<Type> superTypes;
     private final List<FieldDeclarationNode> fields;
     private final List<MethodNode> methods;
 
     public AnonymousClass(
-        Set<TypeName> superTypes,
+        Set<Type> superTypes,
         List<FieldDeclarationNode> fields,
         List<MethodNode> methods)
     {
@@ -23,7 +23,7 @@ public class AnonymousClass {
         this.methods = methods;
     }
 
-    public Set<TypeName> getSuperTypes() {
+    public Set<Type> getSuperTypes() {
         return superTypes;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/TypeName.java b/src/main/java/org/zwobble/couscous/ast/types/ScalarType.java
index e2c32d0..69b9f97 100644
--- a/src/main/java/org/zwobble/couscous/ast/TypeName.java
+++ b/src/main/java/org/zwobble/couscous/ast/types/ScalarType.java
@@ -1,20 +1,20 @@
-package org.zwobble.couscous.ast;
+package org.zwobble.couscous.ast.types;
 
 import com.google.common.base.Strings;
 
 import java.util.Optional;
 
-public class TypeName {
-    public static TypeName of(String qualifiedName) {
+public class ScalarType implements Type {
+    public static ScalarType of(String qualifiedName) {
         if (Strings.isNullOrEmpty(qualifiedName)) {
             throw new IllegalArgumentException("qualifiedName cannot be blank");
         }
-        return new TypeName(qualifiedName);
+        return new ScalarType(qualifiedName);
     }
     
     private final String qualifiedName;
     
-    private TypeName(String qualifiedName) {
+    private ScalarType(String qualifiedName) {
         this.qualifiedName = qualifiedName;
     }
     
@@ -37,7 +37,7 @@ public class TypeName {
 
     @Override
     public String toString() {
-        return "TypeName(qualifiedName=" + qualifiedName + ")";
+        return "ScalarType(qualifiedName=" + qualifiedName + ")";
     }
 
     @Override
@@ -57,7 +57,7 @@ public class TypeName {
             return false;
         if (getClass() != obj.getClass())
             return false;
-        TypeName other = (TypeName) obj;
+        ScalarType other = (ScalarType) obj;
         if (qualifiedName == null) {
             if (other.qualifiedName != null)
                 return false;
@@ -65,4 +65,9 @@ public class TypeName {
             return false;
         return true;
     }
+
+    @Override
+    public <T> T accept(Visitor<T> visitor) {
+        return visitor.visit(this);
+    }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/types/Type.java b/src/main/java/org/zwobble/couscous/ast/types/Type.java
new file mode 100644
index 0000000..e936279
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/types/Type.java
@@ -0,0 +1,9 @@
+package org.zwobble.couscous.ast.types;
+
+public interface Type {
+    <T> T accept(Visitor<T> visitor);
+
+    interface Visitor<T> {
+        T visit(ScalarType type);
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/types/Types.java b/src/main/java/org/zwobble/couscous/ast/types/Types.java
new file mode 100644
index 0000000..c222c54
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/types/Types.java
@@ -0,0 +1,12 @@
+package org.zwobble.couscous.ast.types;
+
+public class Types {
+    public static ScalarType erasure(Type type) {
+        return type.accept(new Type.Visitor<ScalarType>() {
+            @Override
+            public ScalarType visit(ScalarType type) {
+                return type;
+            }
+        });
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java b/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java
index 5d0539a..38c5709 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java
@@ -5,6 +5,8 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import org.zwobble.couscous.ast.*;
+import org.zwobble.couscous.ast.types.ScalarType;
+import org.zwobble.couscous.ast.types.Type;
 
 import java.util.List;
 import java.util.Map;
@@ -154,7 +156,7 @@ public class NodeTransformer {
 
     public static class Builder {
         private Function<ExpressionNode, Optional<ExpressionNode>> transformExpression = expression -> Optional.empty();
-        private Function<TypeName, TypeName> transformType = type -> type;
+        private Function<Type, Type> transformType = type -> type;
         private Function<MethodSignature, String> transformMethodName = MethodSignature::getName;
 
         public Builder transformExpression(
@@ -165,7 +167,7 @@ public class NodeTransformer {
         }
 
         public Builder transformType(
-            Function<TypeName, TypeName> transformType)
+            Function<Type, Type> transformType)
         {
             this.transformType = transformType;
             return this;
@@ -182,12 +184,12 @@ public class NodeTransformer {
     }
 
     private final Function<ExpressionNode, Optional<ExpressionNode>> transformExpression;
-    private final Function<TypeName, TypeName> transformType;
+    private final Function<Type, Type> transformType;
     private final Function<MethodSignature, String> transformMethodName;
 
     private NodeTransformer(
         Function<ExpressionNode, Optional<ExpressionNode>> transformExpression,
-        Function<TypeName, TypeName> transformType,
+        Function<Type, Type> transformType,
         Function<MethodSignature, String> transformMethodName)
     {
         this.transformExpression = transformExpression;
@@ -195,10 +197,14 @@ public class NodeTransformer {
         this.transformMethodName = transformMethodName;
     }
 
-    public TypeName transform(TypeName type) {
+    public Type transform(Type type) {
         return transformType.apply(type);
     }
 
+    public ScalarType transform(ScalarType type) {
+        return (ScalarType)transformType.apply(type);
+    }
+
     public String transformMethodName(MethodSignature signature) {
         return transformMethodName.apply(signature);
     }
@@ -256,7 +262,7 @@ public class NodeTransformer {
         return transformList(annotations, this::transformAnnotation);
     }
 
-    public Set<TypeName> transformTypes(Set<TypeName> superTypes) {
+    public Set<Type> transformTypes(Set<Type> superTypes) {
         return transformSet(superTypes, this::transform);
     }