Improve support for generics

12 files changed, 130 insertions, 33 deletions

diff --git a/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java b/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java
index 43993b8..0078002 100644
--- a/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java
@@ -16,16 +16,36 @@ public class MethodCallNode implements ExpressionNode {
         String className,
         String methodName,
         List<ExpressionNode> arguments,
-        Type type) {
+        Type type)
+    {
         return staticMethodCall(ScalarType.of(className), methodName, arguments, type);
     }
 
     public static ExpressionNode staticMethodCall(
+        String className,
+        String methodName,
+        List<ExpressionNode> arguments,
+        MethodSignature signature)
+    {
+        return staticMethodCall(ScalarType.of(className), methodName, arguments, signature);
+    }
+
+    public static ExpressionNode staticMethodCall(
         ScalarType className,
         String methodName,
         List<ExpressionNode> arguments,
-        Type type) {
-        return MethodCallNode.methodCall(staticReceiver(className), methodName, arguments, type);
+        Type type)
+    {
+        return methodCall(staticReceiver(className), methodName, arguments, type);
+    }
+
+    public static ExpressionNode staticMethodCall(
+        ScalarType className,
+        String methodName,
+        List<ExpressionNode> arguments,
+        MethodSignature signature)
+    {
+        return methodCall(staticReceiver(className), methodName, arguments, signature);
     }
 
     public static MethodCallNode methodCall(
@@ -38,29 +58,51 @@ public class MethodCallNode implements ExpressionNode {
     }
 
     public static MethodCallNode methodCall(
+        ExpressionNode receiver,
+        String methodName,
+        List<ExpressionNode> arguments,
+        MethodSignature signature)
+    {
+        return methodCall(instanceReceiver(receiver), methodName, arguments, signature);
+    }
+
+    public static MethodCallNode methodCall(
         Receiver receiver,
         String methodName,
         List<ExpressionNode> arguments,
         Type type)
     {
-        return new MethodCallNode(receiver, methodName, arguments, type);
+        MethodSignature signature = new MethodSignature(
+            methodName,
+            eagerMap(arguments, argument -> argument.getType()),
+            type);
+        return methodCall(receiver, methodName, arguments, signature);
+    }
+
+    public static MethodCallNode methodCall(
+        Receiver receiver,
+        String methodName,
+        List<ExpressionNode> arguments,
+        MethodSignature signature)
+    {
+        return new MethodCallNode(receiver, methodName, arguments, signature);
     }
     
     private final Receiver receiver;
     private final String methodName;
     private final List<ExpressionNode> arguments;
-    private final Type type;
+    private final MethodSignature signature;
     
     private MethodCallNode(
         Receiver receiver,
         String methodName,
         List<ExpressionNode> arguments,
-        Type type)
+        MethodSignature signature)
     {
         this.receiver = receiver;
         this.methodName = methodName;
         this.arguments = arguments;
-        this.type = type;
+        this.signature = signature;
     }
     
     public Receiver getReceiver() {
@@ -74,16 +116,14 @@ public class MethodCallNode implements ExpressionNode {
     public List<ExpressionNode> getArguments() {
         return arguments;
     }
-    
+
+    @Override
     public Type getType() {
-        return type;
+        return signature.getReturnType();
     }
 
     public MethodSignature signature() {
-        return new MethodSignature(
-            methodName,
-            eagerMap(arguments, argument -> argument.getType()),
-            type);
+        return signature;
     }
     
     @Override
@@ -97,13 +137,13 @@ public class MethodCallNode implements ExpressionNode {
             transformer.transformReceiver(receiver),
             transformer.transformMethodName(signature()),
             transformer.transformExpressions(arguments),
-            transformer.transform(type));
+            transformer.transform(signature));
     }
 
     @Override
     public String toString() {
         return "MethodCallNode(receiver=" + receiver + ", methodName="
-               + methodName + ", arguments=" + arguments + ", type=" + type
+               + methodName + ", arguments=" + arguments + ", signature=" + signature
                + ")";
     }
 
@@ -117,7 +157,7 @@ public class MethodCallNode implements ExpressionNode {
                  + ((methodName == null) ? 0 : methodName.hashCode());
         result = prime * result
                  + ((receiver == null) ? 0 : receiver.hashCode());
-        result = prime * result + ((type == null) ? 0 : type.hashCode());
+        result = prime * result + ((signature == null) ? 0 : signature.hashCode());
         return result;
     }
 
@@ -145,10 +185,10 @@ public class MethodCallNode implements ExpressionNode {
                 return false;
         } else if (!receiver.equals(other.receiver))
             return false;
-        if (type == null) {
-            if (other.type != null)
+        if (signature == null) {
+            if (other.signature != null)
                 return false;
-        } else if (!type.equals(other.type))
+        } else if (!signature.equals(other.signature))
             return false;
         return true;
     }
diff --git a/src/main/java/org/zwobble/couscous/ast/MethodSignature.java b/src/main/java/org/zwobble/couscous/ast/MethodSignature.java
index 93d4f58..4cb04fb 100644
--- a/src/main/java/org/zwobble/couscous/ast/MethodSignature.java
+++ b/src/main/java/org/zwobble/couscous/ast/MethodSignature.java
@@ -5,6 +5,10 @@ import org.zwobble.couscous.ast.types.Type;
 import java.util.List;
 
 public class MethodSignature {
+    public static MethodSignature signature(String name, List<Type> arguments, Type returnType) {
+        return new MethodSignature(name, arguments, returnType);
+    }
+
     private final String name;
     private final List<Type> arguments;
     private final Type returnType;
diff --git a/src/main/java/org/zwobble/couscous/ast/types/TypeParameter.java b/src/main/java/org/zwobble/couscous/ast/types/TypeParameter.java
index 0dee75e..9cda882 100644
--- a/src/main/java/org/zwobble/couscous/ast/types/TypeParameter.java
+++ b/src/main/java/org/zwobble/couscous/ast/types/TypeParameter.java
@@ -13,6 +13,10 @@ public class TypeParameter implements Type {
         this.name = name;
     }
 
+    public ScalarType getDeclaringType() {
+        return declaringType;
+    }
+
     public String getName() {
         return name;
     }
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 38c5709..0998564 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java
@@ -13,6 +13,8 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 
+import static org.zwobble.couscous.util.ExtraLists.eagerMap;
+
 public class NodeTransformer {
     public static NodeTransformer replaceExpressions(Map<ExpressionNode, ExpressionNode> replacements) {
         return builder().
@@ -197,6 +199,13 @@ public class NodeTransformer {
         this.transformMethodName = transformMethodName;
     }
 
+    public MethodSignature transform(MethodSignature signature) {
+        return new MethodSignature(
+            transformMethodName(signature),
+            eagerMap(signature.getArguments(), this::transform),
+            transform(signature.getReturnType()));
+    }
+
     public Type transform(Type type) {
         return transformType.apply(type);
     }
diff --git a/src/main/java/org/zwobble/couscous/backends/Names.java b/src/main/java/org/zwobble/couscous/backends/Names.java
index 1e9600a..4adbec3 100644
--- a/src/main/java/org/zwobble/couscous/backends/Names.java
+++ b/src/main/java/org/zwobble/couscous/backends/Names.java
@@ -25,7 +25,7 @@ public class Names {
 
             @Override
             public String visit(TypeParameter parameter) {
-                return parameter.getName();
+                return typeToString(parameter.getDeclaringType()) + "_" + parameter.getName();
             }
 
             @Override
diff --git a/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java b/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
index 49e7b80..fc3aa98 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
@@ -39,6 +39,7 @@ import static org.zwobble.couscous.backends.python.ast.PythonReturnNode.pythonRe
 import static org.zwobble.couscous.backends.python.ast.PythonStringLiteralNode.pythonStringLiteral;
 import static org.zwobble.couscous.backends.python.ast.PythonVariableReferenceNode.pythonVariableReference;
 import static org.zwobble.couscous.backends.python.ast.PythonWhileNode.pythonWhile;
+import static org.zwobble.couscous.backends.python.ast.visitors.PythonExpressionStatement.pythonExpressionStatement;
 import static org.zwobble.couscous.util.Casts.tryCast;
 import static org.zwobble.couscous.util.ExtraLists.list;
 
@@ -195,10 +196,10 @@ public class PythonCodeGenerator {
         @Override
         public PythonStatementNode visit(ExpressionStatementNode expressionStatement) {
             if (expressionStatement.getExpression() instanceof AssignmentNode) {
-                final org.zwobble.couscous.ast.AssignmentNode assignment = (AssignmentNode)expressionStatement.getExpression();
+                AssignmentNode assignment = (AssignmentNode)expressionStatement.getExpression();
                 return pythonAssignment(assignment.getTarget().accept(EXPRESSION_GENERATOR), generateExpression(assignment.getValue()));
             } else {
-                throw new UnsupportedOperationException();
+                return pythonExpressionStatement(generateExpression(expressionStatement.getExpression()));
             }
         }
 
diff --git a/src/main/java/org/zwobble/couscous/backends/python/PythonSerializer.java b/src/main/java/org/zwobble/couscous/backends/python/PythonSerializer.java
index d3771d3..7732a87 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/PythonSerializer.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/PythonSerializer.java
@@ -2,6 +2,7 @@ package org.zwobble.couscous.backends.python;
 
 import org.zwobble.couscous.backends.SourceCodeWriter;
 import org.zwobble.couscous.backends.python.ast.*;
+import org.zwobble.couscous.backends.python.ast.visitors.PythonExpressionStatement;
 import org.zwobble.couscous.backends.python.ast.visitors.PythonNodeVisitor;
 
 public class PythonSerializer implements PythonNodeVisitor {
@@ -101,7 +102,14 @@ public class PythonSerializer implements PythonNodeVisitor {
         writer.writeSpace();
         writeParenthesised(operation.getRight(), operation);
     }
-    
+
+    @Override
+    public void visit(PythonExpressionStatement statement) {
+        writer.writeStatement(() -> {
+            write(statement.getExpression());
+        });
+    }
+
     @Override
     public void visit(PythonReturnNode pythonReturn) {
         writer.writeStatement(() -> {
diff --git a/src/main/java/org/zwobble/couscous/backends/python/ast/visitors/PythonExpressionStatement.java b/src/main/java/org/zwobble/couscous/backends/python/ast/visitors/PythonExpressionStatement.java
new file mode 100644
index 0000000..0ba1c38
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/backends/python/ast/visitors/PythonExpressionStatement.java
@@ -0,0 +1,25 @@
+package org.zwobble.couscous.backends.python.ast.visitors;
+
+import org.zwobble.couscous.backends.python.ast.PythonExpressionNode;
+import org.zwobble.couscous.backends.python.ast.PythonStatementNode;
+
+public class PythonExpressionStatement implements PythonStatementNode {
+    public static PythonExpressionStatement pythonExpressionStatement(PythonExpressionNode expression) {
+        return new PythonExpressionStatement(expression);
+    }
+
+    private final PythonExpressionNode expression;
+
+    public PythonExpressionStatement(PythonExpressionNode expression) {
+        this.expression = expression;
+    }
+
+    public PythonExpressionNode getExpression() {
+        return expression;
+    }
+
+    @Override
+    public void accept(PythonNodeVisitor visitor) {
+        visitor.visit(this);
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/backends/python/ast/visitors/PythonNodeVisitor.java b/src/main/java/org/zwobble/couscous/backends/python/ast/visitors/PythonNodeVisitor.java
index 8f04787..d43691d 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/ast/visitors/PythonNodeVisitor.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/ast/visitors/PythonNodeVisitor.java
@@ -13,7 +13,8 @@ public interface PythonNodeVisitor {
     void visit(PythonGetSliceNode getSlice);
     void visit(PythonNotNode notOperation);
     void visit(PythonBinaryOperation operation);
-    
+
+    void visit(PythonExpressionStatement statement);
     void visit(PythonReturnNode pythonReturn);
     void visit(PythonPassNode pass);
     void visit(PythonClassNode pythonClass);
@@ -24,5 +25,4 @@ public interface PythonNodeVisitor {
     void visit(PythonWhileNode whileLoop);
 
     void visit(PythonModuleNode module);
-
 }
diff --git a/src/main/java/org/zwobble/couscous/frontends/java/JavaExpressionReader.java b/src/main/java/org/zwobble/couscous/frontends/java/JavaExpressionReader.java
index 096162f..46d2ab4 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/JavaExpressionReader.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/JavaExpressionReader.java
@@ -185,7 +185,6 @@ public class JavaExpressionReader {
             expression.resolveMethodBinding(),
             expression.arguments());
         MethodSignature signature = JavaMethods.signature(expression.resolveMethodBinding());
-        final Type type = signature.getReturnType();
 
         IMethodBinding methodBinding = expression.resolveMethodBinding();
         Type receiverType = typeOf(methodBinding.getDeclaringClass());
@@ -194,7 +193,7 @@ public class JavaExpressionReader {
                 Types.erasure(receiverType),
                 methodName,
                 arguments,
-                type);
+                signature);
         } else {
             ExpressionNode receiver = expression.getExpression() == null
                 ? ThisReferenceNode.thisReference(receiverType)
@@ -203,7 +202,7 @@ public class JavaExpressionReader {
                 receiver,
                 methodName,
                 arguments,
-                type);
+                signature);
         }
     }
 
diff --git a/src/main/java/org/zwobble/couscous/frontends/java/JavaMethods.java b/src/main/java/org/zwobble/couscous/frontends/java/JavaMethods.java
index 42211fe..0273faa 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/JavaMethods.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/JavaMethods.java
@@ -34,10 +34,17 @@ class JavaMethods {
                 eagerMap(
                     argumentTypes,
                     asList(erasedMethod.getParameterTypes()),
-                    (argumentType, erasedParameterType) -> new BoundTypeParameter((TypeParameter) typeOf(erasedParameterType), argumentType)),
-                new BoundTypeParameter(
-                    (TypeParameter) typeOf(erasedMethod.getReturnType()),
-                    returnType));
+                    (argumentType, erasedParameterType) -> typeParameterForGeneric(erasedParameterType, argumentType)),
+                typeParameterForGeneric(erasedMethod.getReturnType(), returnType));
+        }
+    }
+
+    private static Type typeParameterForGeneric(ITypeBinding erasedTypeBinding, Type type) {
+        Type erasedType = typeOf(erasedTypeBinding);
+        if (erasedType.equals(type)) {
+            return type;
+        } else {
+            return new BoundTypeParameter((TypeParameter) typeOf(erasedTypeBinding), type);
         }
     }
 }
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 4afe02b..42d8f28 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/JavaReader.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/JavaReader.java
@@ -417,7 +417,7 @@ public class JavaReader {
                                 thisReference(type),
                                 methodNode.getName(),
                                 eagerMap(arguments, argument -> reference(argument)),
-                                methodNode.getReturnType()),
+                                methodNode.signature()),
                             override.getReturnType()))
                     )));
             });