Remove MethodTypeParameter and adjust Identifier generation

29 files changed, 212 insertions, 196 deletions

diff --git a/src/main/java/org/zwobble/couscous/ast/ClassNodeBuilder.java b/src/main/java/org/zwobble/couscous/ast/ClassNodeBuilder.java
index 734a6a2..4bd432f 100644
--- a/src/main/java/org/zwobble/couscous/ast/ClassNodeBuilder.java
+++ b/src/main/java/org/zwobble/couscous/ast/ClassNodeBuilder.java
@@ -3,6 +3,7 @@ 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.identifiers.Identifiers;
 import org.zwobble.couscous.types.ScalarType;
 import org.zwobble.couscous.types.Type;
 import org.zwobble.couscous.types.Types;
@@ -40,7 +41,7 @@ public class ClassNodeBuilder {
     }
 
     public ClassNodeBuilder addTypeParameter(String name) {
-        this.typeParameters.add(formalTypeParameter(name));
+        this.typeParameters.add(formalTypeParameter(Identifiers.forType(this.name.getQualifiedName()), name));
         return this;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/FormalTypeParameterNode.java b/src/main/java/org/zwobble/couscous/ast/FormalTypeParameterNode.java
index 4582719..3147d1d 100644
--- a/src/main/java/org/zwobble/couscous/ast/FormalTypeParameterNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/FormalTypeParameterNode.java
@@ -1,25 +1,35 @@
 package org.zwobble.couscous.ast;
 
+import org.zwobble.couscous.ast.identifiers.Identifier;
 import org.zwobble.couscous.ast.visitors.NodeMapper;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
+import org.zwobble.couscous.types.TypeParameter;
 
 public class FormalTypeParameterNode implements Node {
-    public static FormalTypeParameterNode formalTypeParameter(String name) {
-        return new FormalTypeParameterNode(name);
+    public static FormalTypeParameterNode formalTypeParameter(Identifier declaringScope, String name) {
+        return new FormalTypeParameterNode(new TypeParameter(declaringScope, name));
     }
 
-    private final String name;
+    public static FormalTypeParameterNode formalTypeParameter(TypeParameter type) {
+        return new FormalTypeParameterNode(type);
+    }
+
+    private final TypeParameter type;
+
+    public FormalTypeParameterNode(TypeParameter type) {
+        this.type = type;
+    }
 
-    public FormalTypeParameterNode(String name) {
-        this.name = name;
+    public TypeParameter getType() {
+        return type;
     }
 
     public String getName() {
-        return name;
+        return type.getName();
     }
 
     public FormalTypeParameterNode transform(NodeTransformer transformer) {
-        return this;
+        return new FormalTypeParameterNode(transformer.transform(type));
     }
 
     @Override
@@ -30,7 +40,7 @@ public class FormalTypeParameterNode implements Node {
     @Override
     public String toString() {
         return "FormalTypeParameterNode(" +
-            "name=" + name +
+            "type=" + type +
             ')';
     }
 
@@ -41,12 +51,12 @@ public class FormalTypeParameterNode implements Node {
 
         FormalTypeParameterNode that = (FormalTypeParameterNode) o;
 
-        return name.equals(that.name);
+        return type.equals(that.type);
 
     }
 
     @Override
     public int hashCode() {
-        return name.hashCode();
+        return type.hashCode();
     }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/MethodNode.java b/src/main/java/org/zwobble/couscous/ast/MethodNode.java
index de86a15..0f91024 100644
--- a/src/main/java/org/zwobble/couscous/ast/MethodNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/MethodNode.java
@@ -10,7 +10,6 @@ import java.util.List;
 import java.util.Optional;
 import java.util.function.Function;
 
-import static org.zwobble.couscous.types.MethodTypeParameter.methodTypeParameter;
 import static org.zwobble.couscous.util.ExtraLists.eagerMap;
 import static org.zwobble.couscous.util.ExtraLists.list;
 
@@ -174,7 +173,7 @@ public class MethodNode implements Node {
     public MethodSignature signature() {
         return new MethodSignature(
             name,
-            eagerMap(typeParameters, parameter -> methodTypeParameter(parameter.getName())),
+            eagerMap(typeParameters, parameter -> parameter.getType()),
             eagerMap(arguments, argument -> argument.getType()),
             returnType);
     }
diff --git a/src/main/java/org/zwobble/couscous/ast/MethodSignature.java b/src/main/java/org/zwobble/couscous/ast/MethodSignature.java
index 8c907e3..d6c42ab 100644
--- a/src/main/java/org/zwobble/couscous/ast/MethodSignature.java
+++ b/src/main/java/org/zwobble/couscous/ast/MethodSignature.java
@@ -1,7 +1,7 @@
 package org.zwobble.couscous.ast;
 
-import org.zwobble.couscous.types.MethodTypeParameter;
 import org.zwobble.couscous.types.Type;
+import org.zwobble.couscous.types.TypeParameter;
 import org.zwobble.couscous.types.Types;
 
 import java.util.List;
@@ -14,16 +14,16 @@ public class MethodSignature {
         return signature(name, list(), arguments, returnType);
     }
 
-    public static MethodSignature signature(String name, List<MethodTypeParameter> typeParameters, List<Type> arguments, Type returnType) {
+    public static MethodSignature signature(String name, List<TypeParameter> typeParameters, List<Type> arguments, Type returnType) {
         return new MethodSignature(name, typeParameters, arguments, returnType);
     }
 
     private final String name;
-    private final List<MethodTypeParameter> typeParameters;
+    private final List<TypeParameter> typeParameters;
     private final List<Type> arguments;
     private final Type returnType;
 
-    public MethodSignature(String name, List<MethodTypeParameter> typeParameters, List<Type> arguments, Type returnType) {
+    public MethodSignature(String name, List<TypeParameter> typeParameters, List<Type> arguments, Type returnType) {
         this.name = name;
         this.typeParameters = typeParameters;
         this.arguments = arguments;
@@ -34,7 +34,7 @@ public class MethodSignature {
         return name;
     }
 
-    public List<MethodTypeParameter> getTypeParameters() {
+    public List<TypeParameter> getTypeParameters() {
         return typeParameters;
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/identifiers/ExtendedIdentifier.java b/src/main/java/org/zwobble/couscous/ast/identifiers/ExtendedIdentifier.java
new file mode 100644
index 0000000..407c6da
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/identifiers/ExtendedIdentifier.java
@@ -0,0 +1,50 @@
+package org.zwobble.couscous.ast.identifiers;
+
+import static org.zwobble.couscous.util.ExtraIterables.lazyAppend;
+
+public class ExtendedIdentifier implements Identifier {
+    private final Identifier parent;
+    private final String part;
+    private final IdentifierType type;
+
+    ExtendedIdentifier(Identifier parent, String part, IdentifierType type) {
+        this.parent = parent;
+        this.part = part;
+        this.type = type;
+    }
+
+    @Override
+    public Iterable<IdentifierPart> getParts() {
+        return lazyAppend(parent.getParts(), new IdentifierPart(part, type));
+    }
+
+    @Override
+    public String toString() {
+        return "ExtendedIdentifier(" +
+            "parent=" + parent +
+            ", part='" + part + '\'' +
+            ", type=" + type +
+            ')';
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        ExtendedIdentifier that = (ExtendedIdentifier) o;
+
+        if (!parent.equals(that.parent)) return false;
+        if (!part.equals(that.part)) return false;
+        return type == that.type;
+
+    }
+
+    @Override
+    public int hashCode() {
+        int result = parent.hashCode();
+        result = 31 * result + part.hashCode();
+        result = 31 * result + type.hashCode();
+        return result;
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/identifiers/Identifier.java b/src/main/java/org/zwobble/couscous/ast/identifiers/Identifier.java
index c753034..777a0bb 100644
--- a/src/main/java/org/zwobble/couscous/ast/identifiers/Identifier.java
+++ b/src/main/java/org/zwobble/couscous/ast/identifiers/Identifier.java
@@ -1,51 +1,5 @@
 package org.zwobble.couscous.ast.identifiers;
 
-import com.google.common.collect.ImmutableList;
-
-import java.util.List;
-
-import static org.zwobble.couscous.util.ExtraLists.list;
-
-public class Identifier {
-    // TODO: Should we have two Identifier classes, one for each namespace? (variables and types)
-    public static final Identifier TOP = new Identifier(list());
-
-    private final List<String> parts;
-
-    private Identifier(List<String> parts) {
-        this.parts = parts;
-    }
-
-    public List<String> getParts() {
-        return parts;
-    }
-
-    public Identifier extend(String name) {
-        ImmutableList.Builder<String> parts = ImmutableList.builder();
-        parts.addAll(this.parts);
-        parts.add(name);
-        return new Identifier(parts.build());
-    }
-
-    @Override
-    public String toString() {
-        return "Identifier(" +
-            "parts=" + parts +
-            ')';
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-
-        Identifier that = (Identifier) o;
-
-        return parts.equals(that.parts);
-    }
-
-    @Override
-    public int hashCode() {
-        return parts.hashCode();
-    }
+public interface Identifier {
+    Iterable<IdentifierPart> getParts();
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/identifiers/IdentifierPart.java b/src/main/java/org/zwobble/couscous/ast/identifiers/IdentifierPart.java
new file mode 100644
index 0000000..5aedcf0
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/identifiers/IdentifierPart.java
@@ -0,0 +1,19 @@
+package org.zwobble.couscous.ast.identifiers;
+
+public class IdentifierPart {
+    private final String name;
+    private final IdentifierType type;
+
+    public IdentifierPart(String name, IdentifierType type) {
+        this.name = name;
+        this.type = type;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public IdentifierType getType() {
+        return type;
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/identifiers/IdentifierType.java b/src/main/java/org/zwobble/couscous/ast/identifiers/IdentifierType.java
new file mode 100644
index 0000000..f18334f
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/identifiers/IdentifierType.java
@@ -0,0 +1,8 @@
+package org.zwobble.couscous.ast.identifiers;
+
+public enum IdentifierType {
+    TYPE,
+    METHOD,
+    CONSTRUCTOR,
+    VARIABLE
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/identifiers/Identifiers.java b/src/main/java/org/zwobble/couscous/ast/identifiers/Identifiers.java
new file mode 100644
index 0000000..9beac27
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/identifiers/Identifiers.java
@@ -0,0 +1,29 @@
+package org.zwobble.couscous.ast.identifiers;
+
+public class Identifiers {
+    public static final Identifier TOP = new TopIdentifier();
+
+    public static Identifier type(Identifier identifier, String name) {
+        return extend(identifier, name, IdentifierType.TYPE);
+    }
+
+    public static Identifier method(Identifier identifier, String name) {
+        return extend(identifier, name, IdentifierType.METHOD);
+    }
+
+    public static Identifier constructor(Identifier identifier) {
+        return extend(identifier, "", IdentifierType.CONSTRUCTOR);
+    }
+
+    public static Identifier variable(Identifier identifier, String name) {
+        return extend(identifier, name, IdentifierType.VARIABLE);
+    }
+
+    private static Identifier extend(Identifier identifier, String name, IdentifierType type) {
+        return new ExtendedIdentifier(identifier, name, type);
+    }
+
+    public static Identifier forType(String name) {
+        return type(TOP, name);
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/identifiers/TopIdentifier.java b/src/main/java/org/zwobble/couscous/ast/identifiers/TopIdentifier.java
new file mode 100644
index 0000000..4776dc1
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/identifiers/TopIdentifier.java
@@ -0,0 +1,12 @@
+package org.zwobble.couscous.ast.identifiers;
+
+import static org.zwobble.couscous.util.ExtraLists.list;
+
+public class TopIdentifier implements Identifier {
+    static final Identifier INSTANCE = new TopIdentifier();
+
+    @Override
+    public Iterable<IdentifierPart> getParts() {
+        return list();
+    }
+}
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 afa1681..6e63059 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java
@@ -5,9 +5,9 @@ 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.types.MethodTypeParameter;
 import org.zwobble.couscous.types.ScalarType;
 import org.zwobble.couscous.types.Type;
+import org.zwobble.couscous.types.TypeParameter;
 
 import java.util.List;
 import java.util.Map;
@@ -221,8 +221,8 @@ public class NodeTransformer {
         return (ScalarType)transformType.apply(type);
     }
 
-    public MethodTypeParameter transform(MethodTypeParameter type) {
-        return (MethodTypeParameter)transformType.apply(type);
+    public TypeParameter transform(TypeParameter type) {
+        return (TypeParameter)transformType.apply(type);
     }
 
     public String transformMethodName(MethodSignature signature) {
diff --git a/src/main/java/org/zwobble/couscous/backends/csharp/CsharpCodeGenerator.java b/src/main/java/org/zwobble/couscous/backends/csharp/CsharpCodeGenerator.java
index 86afe8e..00de205 100644
--- a/src/main/java/org/zwobble/couscous/backends/csharp/CsharpCodeGenerator.java
+++ b/src/main/java/org/zwobble/couscous/backends/csharp/CsharpCodeGenerator.java
@@ -59,11 +59,6 @@ public class CsharpCodeGenerator {
             }
 
             @Override
-            public Type visit(MethodTypeParameter parameter) {
-                return parameter;
-            }
-
-            @Override
             public TypeParameter visit(TypeParameter parameter) {
                 return parameter;
             }
@@ -119,11 +114,6 @@ public class CsharpCodeGenerator {
             }
 
             @Override
-            public Type visit(MethodTypeParameter parameter) {
-                return parameter;
-            }
-
-            @Override
             public TypeParameter visit(TypeParameter parameter) {
                 return parameter;
             }
diff --git a/src/main/java/org/zwobble/couscous/backends/csharp/CsharpSerializer.java b/src/main/java/org/zwobble/couscous/backends/csharp/CsharpSerializer.java
index f5f75ec..13c3756 100644
--- a/src/main/java/org/zwobble/couscous/backends/csharp/CsharpSerializer.java
+++ b/src/main/java/org/zwobble/couscous/backends/csharp/CsharpSerializer.java
@@ -537,12 +537,6 @@ public class CsharpSerializer implements NodeVisitor {
             }
 
             @Override
-            public Void visit(MethodTypeParameter parameter) {
-                writer.writeIdentifier(parameter.getName());
-                return null;
-            }
-
-            @Override
             public Void visit(TypeParameter parameter) {
                 writer.writeIdentifier(parameter.getName());
                 return null;
diff --git a/src/main/java/org/zwobble/couscous/backends/naming/Names.java b/src/main/java/org/zwobble/couscous/backends/naming/Names.java
index 537633b..ff671cd 100644
--- a/src/main/java/org/zwobble/couscous/backends/naming/Names.java
+++ b/src/main/java/org/zwobble/couscous/backends/naming/Names.java
@@ -25,14 +25,9 @@ public class Names {
             }
 
             @Override
-            public String visit(MethodTypeParameter parameter) {
-                return parameter.getName();
-            }
-
-            @Override
             public String visit(TypeParameter parameter) {
-                // TODO
-                Iterable<String> parts = lazyMap(parameter.getDeclaringScope().getParts(), part -> part.replace(".", "_"));
+                // TODO: should we care about the type?
+                Iterable<String> parts = lazyMap(parameter.getDeclaringScope().getParts(), part -> part.getName().replace(".", "_"));
                 return String.join("_", parts) + "_" + parameter.getName();
             }
 
diff --git a/src/main/java/org/zwobble/couscous/frontends/java/JavaReader.java b/src/main/java/org/zwobble/couscous/frontends/java/JavaReader.java
index 063ffc6..44cbfab 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/JavaReader.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/JavaReader.java
@@ -6,6 +6,7 @@ import com.google.common.collect.Maps;
 import org.eclipse.jdt.core.compiler.IProblem;
 import org.eclipse.jdt.core.dom.*;
 import org.zwobble.couscous.ast.*;
+import org.zwobble.couscous.ast.identifiers.Identifier;
 import org.zwobble.couscous.ast.sugar.AnonymousClass;
 import org.zwobble.couscous.ast.sugar.Lambda;
 import org.zwobble.couscous.ast.sugar.TypeDeclarationBody;
@@ -98,7 +99,7 @@ public class JavaReader {
     private TypeNode readTypeDeclaration(TypeDeclaration type) {
         ScalarType name = erasure(typeOf(type.resolveBinding()));
         Scope scope = topScope.enterClass(name);
-        List<FormalTypeParameterNode> typeParameters = readTypeParameters(type);
+        List<FormalTypeParameterNode> typeParameters = readTypeParameters(scope.getIdentifier(), type);
         TypeDeclarationBody body = readTypeDeclarationBody(scope, name, type.bodyDeclarations());
         Set<Type> superTypes = superTypes(type);
         if (type.isInterface()) {
@@ -116,14 +117,14 @@ public class JavaReader {
         }
     }
 
-    private List<FormalTypeParameterNode> readTypeParameters(TypeDeclaration typeDeclaration) {
-        return readTypeParameters(typeDeclaration.resolveBinding().getTypeParameters());
+    private List<FormalTypeParameterNode> readTypeParameters(Identifier declaringScope, TypeDeclaration typeDeclaration) {
+        return readTypeParameters(declaringScope, typeDeclaration.resolveBinding().getTypeParameters());
     }
 
-    private List<FormalTypeParameterNode> readTypeParameters(ITypeBinding[] typeParameters) {
+    private List<FormalTypeParameterNode> readTypeParameters(Identifier declaringScope, ITypeBinding[] typeParameters) {
         return eagerMap(
             asList(typeParameters),
-            parameter -> formalTypeParameter(parameter.getName()));
+            parameter -> formalTypeParameter(declaringScope, parameter.getName()));
     }
 
     GeneratedClosure readExpressionMethodReference(Scope outerScope, ExpressionMethodReference expression) {
@@ -420,7 +421,7 @@ public class JavaReader {
                 annotations,
                 isStatic,
                 methodName,
-                readTypeParameters(method.resolveBinding().getTypeParameters()),
+                readTypeParameters(scope.getIdentifier(), method.resolveBinding().getTypeParameters()),
                 formalArguments,
                 returnType.get(),
                 body,
diff --git a/src/main/java/org/zwobble/couscous/frontends/java/JavaTypes.java b/src/main/java/org/zwobble/couscous/frontends/java/JavaTypes.java
index 4b3c5ea..1e373d8 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/JavaTypes.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/JavaTypes.java
@@ -3,6 +3,7 @@ package org.zwobble.couscous.frontends.java;
 import com.google.common.collect.ImmutableSet;
 import org.eclipse.jdt.core.dom.*;
 import org.zwobble.couscous.ast.identifiers.Identifier;
+import org.zwobble.couscous.ast.identifiers.Identifiers;
 import org.zwobble.couscous.types.*;
 import org.zwobble.couscous.types.ParameterizedType;
 import org.zwobble.couscous.types.Type;
@@ -64,14 +65,14 @@ public class JavaTypes {
         if (typeParameter.getDeclaringClass() == null) {
             IMethodBinding method = typeParameter.getDeclaringMethod();
             // TODO: disambiguate overloads
-            return identifierForType(method.getDeclaringClass()).extend(method.getName());
+            return Identifiers.method(identifierForType(method.getDeclaringClass()), method.getName());
         } else {
             return identifierForType(typeParameter.getDeclaringClass());
         }
     }
 
     private static Identifier identifierForType(ITypeBinding type) {
-        return Identifier.TOP.extend(erasure(typeOf(type)).getQualifiedName());
+        return Identifiers.forType(erasure(typeOf(type)).getQualifiedName());
     }
 
     static Set<Type> superTypes(TypeDeclaration declaration) {
diff --git a/src/main/java/org/zwobble/couscous/frontends/java/Scope.java b/src/main/java/org/zwobble/couscous/frontends/java/Scope.java
index 98dd30b..0cc369b 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/Scope.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/Scope.java
@@ -2,6 +2,7 @@ package org.zwobble.couscous.frontends.java;
 
 import org.zwobble.couscous.ast.*;
 import org.zwobble.couscous.ast.identifiers.Identifier;
+import org.zwobble.couscous.ast.identifiers.Identifiers;
 import org.zwobble.couscous.types.ScalarType;
 import org.zwobble.couscous.types.Type;
 import org.zwobble.couscous.util.NaturalNumbers;
@@ -10,7 +11,7 @@ import java.util.*;
 
 public class Scope {
     public static Scope create() {
-        return new Scope(new HashMap<>(), new HashSet<>(), Identifier.TOP, NaturalNumbers.INSTANCE.iterator());
+        return new Scope(new HashMap<>(), new HashSet<>(), Identifiers.TOP, NaturalNumbers.INSTANCE.iterator());
     }
 
     private final Map<String, VariableDeclaration> variablesByKey;
@@ -30,21 +31,25 @@ public class Scope {
         this.temporaryCounter = temporaryCounter;
     }
 
+    public Identifier getIdentifier() {
+        return identifier;
+    }
+
     public Scope enterClass(ScalarType className) {
-        return enter("class#" + className.getQualifiedName());
+        return enter(Identifiers.type(identifier, className.getQualifiedName()));
     }
 
     public Scope enterConstructor() {
-        return enter("constructor");
+        return enter(Identifiers.constructor(identifier));
     }
 
     public Scope enterMethod(String name) {
         // TODO: distinguish overloads
-        return enter("method#" + name);
+        return enter(Identifiers.method(identifier, name));
     }
 
-    private Scope enter(String name) {
-        return new Scope(variablesByKey, identifiers, identifier.extend(name), temporaryCounter);
+    private Scope enter(Identifier newIdentifier) {
+        return new Scope(variablesByKey, identifiers, newIdentifier, temporaryCounter);
     }
 
     public FormalArgumentNode formalArgument(String name, Type type) {
@@ -102,15 +107,15 @@ public class Scope {
     }
 
     public VariableDeclaration generateVariable(String name, Type type) {
-        Identifier identifier = generateIdentifier(name);
+        Identifier identifier = generateVariableIdentifier(name);
         return VariableDeclaration.var(identifier, name, type);
     }
 
-    private Identifier generateIdentifier(String name) {
-        Identifier identifier = this.identifier.extend(name);
+    private Identifier generateVariableIdentifier(String name) {
+        Identifier identifier = Identifiers.variable(this.identifier, name);
         int index = 0;
         while (identifiers.contains(identifier)) {
-            identifier = this.identifier.extend(name + "_" + index);
+            identifier = Identifiers.variable(this.identifier, name + "_" + index);
             index++;
         }
         identifiers.add(identifier);
diff --git a/src/main/java/org/zwobble/couscous/interpreter/types/UserDefinedInterpreterType.java b/src/main/java/org/zwobble/couscous/interpreter/types/UserDefinedInterpreterType.java
index c296d01..07199bb 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/types/UserDefinedInterpreterType.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/types/UserDefinedInterpreterType.java
@@ -1,7 +1,6 @@
 package org.zwobble.couscous.interpreter.types;
 
 import org.zwobble.couscous.ast.*;
-import org.zwobble.couscous.ast.identifiers.Identifier;
 import org.zwobble.couscous.interpreter.Arguments;
 import org.zwobble.couscous.interpreter.Environment;
 import org.zwobble.couscous.interpreter.Executor;
@@ -10,7 +9,6 @@ import org.zwobble.couscous.interpreter.errors.NoSuchMethod;
 import org.zwobble.couscous.interpreter.errors.WrongNumberOfArguments;
 import org.zwobble.couscous.interpreter.values.InterpreterValue;
 import org.zwobble.couscous.types.Type;
-import org.zwobble.couscous.types.TypeParameter;
 
 import java.util.List;
 import java.util.Map;
@@ -49,7 +47,7 @@ public class UserDefinedInterpreterType implements InterpreterType {
     public Type getType() {
         List<Type> parameters = eagerMap(
             type.getTypeParameters(),
-            parameter -> new TypeParameter(Identifier.TOP.extend(type.getName().getQualifiedName()), parameter.getName()));
+            parameter -> parameter.getType());
         return parameters.isEmpty()
             ? type.getName()
             : parameterizedType(type.getName(), parameters);
diff --git a/src/main/java/org/zwobble/couscous/types/MethodTypeParameter.java b/src/main/java/org/zwobble/couscous/types/MethodTypeParameter.java
deleted file mode 100644
index 323ec17..0000000
--- a/src/main/java/org/zwobble/couscous/types/MethodTypeParameter.java
+++ /dev/null
@@ -1,45 +0,0 @@
-package org.zwobble.couscous.types;
-
-public class MethodTypeParameter implements Type {
-    public static MethodTypeParameter methodTypeParameter(String name) {
-        return new MethodTypeParameter(name);
-    }
-
-    private final String name;
-
-    public MethodTypeParameter(String name) {
-        this.name = name;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    @Override
-    public <T> T accept(Visitor<T> visitor) {
-        return visitor.visit(this);
-    }
-
-    @Override
-    public String toString() {
-        return "MethodTypeParameter(" +
-            "name=" + name +
-            ')';
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-
-        MethodTypeParameter that = (MethodTypeParameter) o;
-
-        return name.equals(that.name);
-
-    }
-
-    @Override
-    public int hashCode() {
-        return name.hashCode();
-    }
-}
diff --git a/src/main/java/org/zwobble/couscous/types/Type.java b/src/main/java/org/zwobble/couscous/types/Type.java
index 5261aa2..ad0f6fc 100644
--- a/src/main/java/org/zwobble/couscous/types/Type.java
+++ b/src/main/java/org/zwobble/couscous/types/Type.java
@@ -5,7 +5,6 @@ public interface Type {
 
     interface Visitor<T> {
         T visit(ScalarType type);
-        T visit(MethodTypeParameter parameter);
         T visit(TypeParameter parameter);
         T visit(ParameterizedType type);
         T visit(BoundTypeParameter type);
diff --git a/src/main/java/org/zwobble/couscous/types/Types.java b/src/main/java/org/zwobble/couscous/types/Types.java
index 1dfc202..89e88a6 100644
--- a/src/main/java/org/zwobble/couscous/types/Types.java
+++ b/src/main/java/org/zwobble/couscous/types/Types.java
@@ -28,11 +28,6 @@ public class Types {
             }
 
             @Override
-            public ScalarType visit(MethodTypeParameter parameter) {
-                return OBJECT;
-            }
-
-            @Override
             public ScalarType visit(TypeParameter parameter) {
                 return OBJECT;
             }
@@ -57,11 +52,6 @@ public class Types {
             }
 
             @Override
-            public Type visit(MethodTypeParameter parameter) {
-                return parameter;
-            }
-
-            @Override
             public Type visit(TypeParameter type) {
                 return replacements.getOrDefault(type, type);
             }
@@ -88,11 +78,6 @@ public class Types {
             }
 
             @Override
-            public Type visit(MethodTypeParameter parameter) {
-                return parameter;
-            }
-
-            @Override
             public Type visit(TypeParameter parameter) {
                 return parameter;
             }
diff --git a/src/main/java/org/zwobble/couscous/util/ExtraIterables.java b/src/main/java/org/zwobble/couscous/util/ExtraIterables.java
index a77869d..0fcc9af 100644
--- a/src/main/java/org/zwobble/couscous/util/ExtraIterables.java
+++ b/src/main/java/org/zwobble/couscous/util/ExtraIterables.java
@@ -78,6 +78,10 @@ public class ExtraIterables {
         };
     }
 
+    public static <T> Iterable<T> lazyAppend(Iterable<T> head, T tail) {
+        return Iterables.concat(head, list(tail));
+    }
+
     public static <T> Iterable<T> lazyCons(T head, Iterable<T> tails) {
         return Iterables.concat(list(head), tails);
     }
diff --git a/src/test/java/org/zwobble/couscous/tests/BackendMethodTests.java b/src/test/java/org/zwobble/couscous/tests/BackendMethodTests.java
index 635dae8..dcb7d9e 100644
--- a/src/test/java/org/zwobble/couscous/tests/BackendMethodTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/BackendMethodTests.java
@@ -117,8 +117,8 @@ public abstract class BackendMethodTests {
 
     @Test
     public void whileLoopIsExecutedWhileConditionIsTrue() {
-        LocalVariableDeclarationNode x = localVariableDeclaration(TestIds.id("x"), "x", Types.INT, literal(0));
-        LocalVariableDeclarationNode y = localVariableDeclaration(TestIds.id("y"), "y", Types.INT, literal(2));
+        LocalVariableDeclarationNode x = localVariableDeclaration(TestIds.variable("x"), "x", Types.INT, literal(0));
+        LocalVariableDeclarationNode y = localVariableDeclaration(TestIds.variable("y"), "y", Types.INT, literal(2));
         MethodNode.Builder method = staticMethod("hello")
             .returns(Types.INT)
             .statement(x)
@@ -132,8 +132,8 @@ public abstract class BackendMethodTests {
 
     @Test
     public void returnWillExitWhileLoopEarly() {
-        LocalVariableDeclarationNode x = localVariableDeclaration(TestIds.id("x"), "x", Types.INT, literal(0));
-        LocalVariableDeclarationNode y = localVariableDeclaration(TestIds.id("y"), "y", Types.INT, literal(2));
+        LocalVariableDeclarationNode x = localVariableDeclaration(TestIds.variable("x"), "x", Types.INT, literal(0));
+        LocalVariableDeclarationNode y = localVariableDeclaration(TestIds.variable("y"), "y", Types.INT, literal(2));
         MethodNode.Builder method = staticMethod("hello")
             .returns(Types.INT)
             .statement(x)
diff --git a/src/test/java/org/zwobble/couscous/tests/TestIds.java b/src/test/java/org/zwobble/couscous/tests/TestIds.java
index b32cf84..da3cd09 100644
--- a/src/test/java/org/zwobble/couscous/tests/TestIds.java
+++ b/src/test/java/org/zwobble/couscous/tests/TestIds.java
@@ -1,11 +1,12 @@
 package org.zwobble.couscous.tests;
 
 import org.zwobble.couscous.ast.identifiers.Identifier;
+import org.zwobble.couscous.ast.identifiers.Identifiers;
 
 public class TestIds {
-    public static final Identifier ANY_ID = Identifier.TOP.extend("[any id]");
+    public static final Identifier ANY_ID = Identifiers.variable(Identifiers.TOP, "[any id]");
 
-    public static Identifier id(String name) {
-        return ANY_ID.extend(name);
+    public static Identifier variable(String name) {
+        return Identifiers.variable(ANY_ID, name);
     }
 }
diff --git a/src/test/java/org/zwobble/couscous/tests/ValueObjectTests.java b/src/test/java/org/zwobble/couscous/tests/ValueObjectTests.java
index 0e96500..06906ca 100644
--- a/src/test/java/org/zwobble/couscous/tests/ValueObjectTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/ValueObjectTests.java
@@ -61,7 +61,6 @@ public class ValueObjectTests {
             {LocalVariableDeclarationNode.class},
             {MethodCallNode.class},
             {MethodNode.class},
-            {MethodTypeParameter.class},
             {OperationNode.class},
             {ParameterizedType.class},
             {ReturnNode.class},
@@ -151,7 +150,7 @@ public class ValueObjectTests {
         } else if (type.equals(Operator.class)) {
             return Operator.DIVIDE;
         } else if (type.equals(Identifier.class)) {
-            return TestIds.id((String)generateFirstInstance(String.class));
+            return TestIds.variable((String)generateFirstInstance(String.class));
         } else if (type.equals(PrimitiveValue.class)) {
             return generateFirstInstance(StringValue.class);
         } else if (type.equals(ExpressionNode.class)) {
@@ -181,7 +180,7 @@ public class ValueObjectTests {
         } else if (type.equals(Operator.class)) {
             return Operator.MULTIPLY;
         } else if (type.equals(Identifier.class)) {
-            return TestIds.id((String)generateSecondInstance(String.class));
+            return TestIds.variable((String)generateSecondInstance(String.class));
         } else if (type.equals(PrimitiveValue.class)) {
             return generateSecondInstance(StringValue.class);
         } else if (type.equals(ExpressionNode.class)) {
@@ -211,7 +210,7 @@ public class ValueObjectTests {
         } else if (type.equals(Operator.class)) {
             return Operator.ADD;
         } else if (type.equals(Identifier.class)) {
-            return TestIds.id((String)generateInstance(String.class));
+            return TestIds.variable((String)generateInstance(String.class));
         } else if (type.equals(PrimitiveValue.class)) {
             return generateInstance(StringValue.class);
         } else if (type.equals(ExpressionNode.class)) {
diff --git a/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpSerializerTests.java b/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpSerializerTests.java
index a2f838f..52849dc 100644
--- a/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpSerializerTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpSerializerTests.java
@@ -304,8 +304,8 @@ public class CsharpSerializerTests {
     @Test
     public void methodWithArguments() {
         MethodNode methodNode = MethodNode.staticMethod("nothing")
-            .argument(formalArg(var(TestIds.id("x"), "x", ScalarType.of("X"))))
-            .argument(formalArg(var(TestIds.id("y"), "y", ScalarType.of("Y"))))
+            .argument(formalArg(var(TestIds.variable("x"), "x", ScalarType.of("X"))))
+            .argument(formalArg(var(TestIds.variable("y"), "y", ScalarType.of("Y"))))
             .returns(ScalarType.of("void"))
             .build();
 
diff --git a/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaReaderTests.java b/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaReaderTests.java
index 971ddd9..e9e75c4 100644
--- a/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaReaderTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaReaderTests.java
@@ -3,6 +3,7 @@ package org.zwobble.couscous.tests.frontends.java;
 import org.junit.Test;
 import org.zwobble.couscous.ast.*;
 import org.zwobble.couscous.ast.identifiers.Identifier;
+import org.zwobble.couscous.ast.identifiers.Identifiers;
 import org.zwobble.couscous.types.ScalarType;
 import org.zwobble.couscous.types.Types;
 
@@ -92,10 +93,13 @@ public class JavaReaderTests {
             "}");
 
         MethodNode method = classNode.getMethods().get(0);
-        assertThat(method.getTypeParameters(), contains(isFormalTypeParameter("T")));
+
+        Identifier classIdentifier = Identifiers.forType("com.example.Example");
+        Identifier expectedMethodIdentifier = Identifiers.method(classIdentifier, "identity");
+        assertThat(method.getTypeParameters(), contains(isFormalTypeParameter(expectedMethodIdentifier, "T")));
         assertThat(
             method.getArguments(),
-            contains(isFormalArgument("value", typeParameter(Identifier.TOP.extend("com.example.Example").extend("identity"), "T"))));
+            contains(isFormalArgument("value",  typeParameter(expectedMethodIdentifier, "T"))));
     }
     
     @Test
@@ -337,7 +341,7 @@ public class JavaReaderTests {
         assertThat(classes, hasSize(1));
         ClassNode classNode = (ClassNode) classes.get(0);
         assertEquals(ScalarType.of("com.example.Example"), classNode.getName());
-        assertEquals(list(formalTypeParameter("T")), classNode.getTypeParameters());
+        assertEquals(list(formalTypeParameter(Identifiers.forType("com.example.Example"), "T")), classNode.getTypeParameters());
     }
 
     @Test
@@ -348,7 +352,7 @@ public class JavaReaderTests {
         assertThat(classes, hasSize(1));
         InterfaceNode classNode = (InterfaceNode) classes.get(0);
         assertEquals(ScalarType.of("com.example.Example"), classNode.getName());
-        assertEquals(list(formalTypeParameter("T")), classNode.getTypeParameters());
+        assertEquals(list(formalTypeParameter(Identifiers.forType("com.example.Example"), "T")), classNode.getTypeParameters());
     }
 
     @Test
diff --git a/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaTypesTests.java b/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaTypesTests.java
index 329ccc7..75c3594 100644
--- a/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaTypesTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaTypesTests.java
@@ -1,7 +1,7 @@
 package org.zwobble.couscous.tests.frontends.java;
 
 import org.junit.Test;
-import org.zwobble.couscous.ast.identifiers.Identifier;
+import org.zwobble.couscous.ast.identifiers.Identifiers;
 import org.zwobble.couscous.frontends.java.JavaTypes;
 import org.zwobble.couscous.types.ScalarType;
 import org.zwobble.couscous.types.TypeParameter;
@@ -24,7 +24,7 @@ public class JavaTypesTests {
 
     @Test
     public void bindingTypeToGenericTypeParameterReturnsBoundTypeParameter() {
-        TypeParameter typeParameter = typeParameter(Identifier.TOP.extend("List"), "T");
+        TypeParameter typeParameter = typeParameter(Identifiers.forType("List"), "T");
         assertEquals(
             boundTypeParameter(typeParameter, INT_TYPE),
             JavaTypes.bind(typeParameter, INT_TYPE));
@@ -33,7 +33,7 @@ public class JavaTypesTests {
     @Test
     public void bindingTypeToParameterizedTypeBindsParameters() {
         ScalarType rawList = ScalarType.of("List");
-        TypeParameter typeParameter = typeParameter(Identifier.TOP.extend("List"), "T");
+        TypeParameter typeParameter = typeParameter(Identifiers.forType("List"), "T");
         assertEquals(
             parameterizedType(rawList, list(boundTypeParameter(typeParameter, INT_TYPE))),
             JavaTypes.bind(
diff --git a/src/test/java/org/zwobble/couscous/tests/frontends/java/NodeMatchers.java b/src/test/java/org/zwobble/couscous/tests/frontends/java/NodeMatchers.java
index 104cf8b..5ef5344 100644
--- a/src/test/java/org/zwobble/couscous/tests/frontends/java/NodeMatchers.java
+++ b/src/test/java/org/zwobble/couscous/tests/frontends/java/NodeMatchers.java
@@ -2,6 +2,7 @@ package org.zwobble.couscous.tests.frontends.java;
 
 import org.hamcrest.Matcher;
 import org.zwobble.couscous.ast.*;
+import org.zwobble.couscous.ast.identifiers.Identifier;
 import org.zwobble.couscous.types.Type;
 
 import static org.hamcrest.Matchers.allOf;
@@ -14,8 +15,10 @@ public class NodeMatchers {
         return hasFeature("initial value", node -> node.getInitialValue(), matcher);
     }
 
-    public static Matcher<FormalTypeParameterNode> isFormalTypeParameter(String name) {
-        return hasFeature("name", node -> node.getName(), equalTo(name));
+    public static Matcher<FormalTypeParameterNode> isFormalTypeParameter(Identifier declaringScope, String name) {
+        return allOf(
+            hasFeature("name", node -> node.getType().getName(), equalTo(name)),
+            hasFeature("declaringScope", node -> node.getType().getDeclaringScope(), equalTo(declaringScope)));
     }
 
     public static Matcher<FormalArgumentNode> isFormalArgument(String name, Type type) {