Add support for static method calls to Python backend

27 files changed, 432 insertions, 50 deletions

diff --git a/src/main/java/org/zwobble/couscous/ast/AssignmentNode.java b/src/main/java/org/zwobble/couscous/ast/AssignmentNode.java
index 8989ef3..349b492 100644
--- a/src/main/java/org/zwobble/couscous/ast/AssignmentNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/AssignmentNode.java
@@ -1,6 +1,6 @@
 package org.zwobble.couscous.ast;
 
-import org.zwobble.couscous.ast.visitors.ExpressionNodeVisitor;
+import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.values.TypeReference;
 
 import static org.zwobble.couscous.ast.VariableReferenceNode.reference;
@@ -17,7 +17,7 @@ public class AssignmentNode implements ExpressionNode {
     ExpressionNode value;
     
     @Override
-    public <T> T accept(ExpressionNodeVisitor<T> visitor) {
+    public <T> T accept(ExpressionNodeMapper<T> visitor) {
         return visitor.visit(this);
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/ClassNode.java b/src/main/java/org/zwobble/couscous/ast/ClassNode.java
index 3d785d2..77480b5 100644
--- a/src/main/java/org/zwobble/couscous/ast/ClassNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/ClassNode.java
@@ -2,13 +2,15 @@ package org.zwobble.couscous.ast;
 
 import java.util.List;
 
+import org.zwobble.couscous.ast.visitors.NodeVisitor;
+
 import com.google.common.collect.ImmutableList;
 
 import lombok.Singular;
 import lombok.Value;
 
 @Value
-public class ClassNode {
+public class ClassNode implements Node {
     public static ClassNode.Builder builder(String name) {
         return new Builder(name);
     }
@@ -40,4 +42,9 @@ public class ClassNode {
         // TODO Stronger notion of class names? Should look up the terminology
         return name.substring(name.lastIndexOf(".") + 1);
     }
+
+    @Override
+    public void accept(NodeVisitor visitor) {
+        visitor.visit(this);
+    }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java b/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java
index bc27a99..297133d 100644
--- a/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java
@@ -1,9 +1,51 @@
 package org.zwobble.couscous.ast;
 
-import org.zwobble.couscous.ast.visitors.ExpressionNodeVisitor;
+import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
+import org.zwobble.couscous.ast.visitors.NodeVisitor;
 import org.zwobble.couscous.values.TypeReference;
 
-public interface ExpressionNode {
+public interface ExpressionNode extends Node {
     TypeReference getType();
-    <T> T accept(ExpressionNodeVisitor<T> visitor);
+    <T> T accept(ExpressionNodeMapper<T> visitor);
+    
+    @Override
+    default void accept(NodeVisitor visitor) {
+        accept(new ExpressionNodeMapper<Void>() {
+            @Override
+            public Void visit(LiteralNode literal) {
+                visitor.visit(literal);
+                return null;
+            }
+
+            @Override
+            public Void visit(VariableReferenceNode variableReference) {
+                visitor.visit(variableReference);
+                return null;
+            }
+
+            @Override
+            public Void visit(AssignmentNode assignment) {
+                visitor.visit(assignment);
+                return null;
+            }
+
+            @Override
+            public Void visit(TernaryConditionalNode ternaryConditional) {
+                visitor.visit(ternaryConditional);
+                return null;
+            }
+
+            @Override
+            public Void visit(MethodCallNode methodCall) {
+                visitor.visit(methodCall);
+                return null;
+            }
+
+            @Override
+            public Void visit(StaticMethodCallNode staticMethodCall) {
+                visitor.visit(staticMethodCall);
+                return null;
+            }
+        });
+    }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/ExpressionStatementNode.java b/src/main/java/org/zwobble/couscous/ast/ExpressionStatementNode.java
index ec04663..5bbe2b5 100644
--- a/src/main/java/org/zwobble/couscous/ast/ExpressionStatementNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/ExpressionStatementNode.java
@@ -1,6 +1,6 @@
 package org.zwobble.couscous.ast;
 
-import org.zwobble.couscous.ast.visitors.StatementNodeVisitor;
+import org.zwobble.couscous.ast.visitors.StatementNodeMapper;
 
 import lombok.Value;
 
@@ -9,7 +9,7 @@ public class ExpressionStatementNode implements StatementNode {
     ExpressionNode expression;
 
     @Override
-    public <T> T accept(StatementNodeVisitor<T> visitor) {
+    public <T> T accept(StatementNodeMapper<T> visitor) {
         return visitor.visit(this);
     }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/LiteralNode.java b/src/main/java/org/zwobble/couscous/ast/LiteralNode.java
index 2d77cd4..a608104 100644
--- a/src/main/java/org/zwobble/couscous/ast/LiteralNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/LiteralNode.java
@@ -1,6 +1,6 @@
 package org.zwobble.couscous.ast;
 
-import org.zwobble.couscous.ast.visitors.ExpressionNodeVisitor;
+import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.values.BooleanValue;
 import org.zwobble.couscous.values.IntegerValue;
 import org.zwobble.couscous.values.PrimitiveValue;
@@ -33,7 +33,7 @@ public class LiteralNode implements ExpressionNode {
     TypeReference type;
 
     @Override
-    public <T> T accept(ExpressionNodeVisitor<T> visitor) {
+    public <T> T accept(ExpressionNodeMapper<T> visitor) {
         return visitor.visit(this);
     }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/LocalVariableDeclarationNode.java b/src/main/java/org/zwobble/couscous/ast/LocalVariableDeclarationNode.java
index cf6c5f0..2b5c63a 100644
--- a/src/main/java/org/zwobble/couscous/ast/LocalVariableDeclarationNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/LocalVariableDeclarationNode.java
@@ -1,6 +1,6 @@
 package org.zwobble.couscous.ast;
 
-import org.zwobble.couscous.ast.visitors.StatementNodeVisitor;
+import org.zwobble.couscous.ast.visitors.StatementNodeMapper;
 import org.zwobble.couscous.values.TypeReference;
 
 import static org.zwobble.couscous.ast.VariableDeclaration.var;
@@ -21,7 +21,7 @@ public class LocalVariableDeclarationNode implements VariableNode, StatementNode
     ExpressionNode initialValue;
     
     @Override
-    public <T> T accept(StatementNodeVisitor<T> visitor) {
+    public <T> T accept(StatementNodeMapper<T> visitor) {
         return visitor.visit(this);
     }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java b/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java
index f240971..e1358c2 100644
--- a/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java
@@ -2,7 +2,7 @@ package org.zwobble.couscous.ast;
 
 import java.util.List;
 
-import org.zwobble.couscous.ast.visitors.ExpressionNodeVisitor;
+import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.values.TypeReference;
 
 import lombok.Value;
@@ -23,7 +23,7 @@ public class MethodCallNode implements ExpressionNode {
     }
     
     @Override
-    public <T> T accept(ExpressionNodeVisitor<T> visitor) {
+    public <T> T accept(ExpressionNodeMapper<T> visitor) {
         return visitor.visit(this);
     }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/MethodNode.java b/src/main/java/org/zwobble/couscous/ast/MethodNode.java
index 91acbd5..e924299 100644
--- a/src/main/java/org/zwobble/couscous/ast/MethodNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/MethodNode.java
@@ -2,13 +2,15 @@ package org.zwobble.couscous.ast;
 
 import java.util.List;
 
+import org.zwobble.couscous.ast.visitors.NodeVisitor;
+
 import lombok.Builder;
 import lombok.Singular;
 import lombok.Value;
 
 @Builder
 @Value
-public class MethodNode {
+public class MethodNode implements Node {
     public static MethodNodeBuilder staticMethod(String name) {
         return builder().isStatic(true).name(name);
     }
@@ -19,4 +21,9 @@ public class MethodNode {
     List<FormalArgumentNode> arguments; 
     @Singular("statement")
     List<StatementNode> body;
+    
+    @Override
+    public void accept(NodeVisitor visitor) {
+        visitor.visit(this);
+    }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/Node.java b/src/main/java/org/zwobble/couscous/ast/Node.java
new file mode 100644
index 0000000..acde931
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/Node.java
@@ -0,0 +1,7 @@
+package org.zwobble.couscous.ast;
+
+import org.zwobble.couscous.ast.visitors.NodeVisitor;
+
+public interface Node {
+    void accept(NodeVisitor visitor);
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/ReturnNode.java b/src/main/java/org/zwobble/couscous/ast/ReturnNode.java
index 529dbb5..7f4a57e 100644
--- a/src/main/java/org/zwobble/couscous/ast/ReturnNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/ReturnNode.java
@@ -1,6 +1,6 @@
 package org.zwobble.couscous.ast;
 
-import org.zwobble.couscous.ast.visitors.StatementNodeVisitor;
+import org.zwobble.couscous.ast.visitors.StatementNodeMapper;
 
 import lombok.Value;
 
@@ -9,7 +9,7 @@ public class ReturnNode implements StatementNode {
     ExpressionNode value;
 
     @Override
-    public <T> T accept(StatementNodeVisitor<T> visitor) {
+    public <T> T accept(StatementNodeMapper<T> visitor) {
         return visitor.visit(this);
     }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/StatementNode.java b/src/main/java/org/zwobble/couscous/ast/StatementNode.java
index 773420e..7a1b25b 100644
--- a/src/main/java/org/zwobble/couscous/ast/StatementNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/StatementNode.java
@@ -1,7 +1,32 @@
 package org.zwobble.couscous.ast;
 
-import org.zwobble.couscous.ast.visitors.StatementNodeVisitor;
+import org.zwobble.couscous.ast.visitors.NodeVisitor;
+import org.zwobble.couscous.ast.visitors.StatementNodeMapper;
 
-public interface StatementNode {
-    <T> T accept(StatementNodeVisitor<T> visitor); 
+public interface StatementNode extends Node {
+    <T> T accept(StatementNodeMapper<T> visitor);
+    
+    @Override
+    default void accept(NodeVisitor visitor) {
+        accept(new StatementNodeMapper<Void>() {
+            @Override
+            public Void visit(ReturnNode returnNode) {
+                visitor.visit(returnNode);
+                return null;
+            }
+
+            @Override
+            public Void visit(ExpressionStatementNode expressionStatement) {
+                visitor.visit(expressionStatement);
+                return null;
+            }
+
+            @Override
+            public Void visit(
+                LocalVariableDeclarationNode localVariableDeclaration) {
+                visitor.visit(localVariableDeclaration);
+                return null;
+            }
+        });
+    }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/StaticMethodCallNode.java b/src/main/java/org/zwobble/couscous/ast/StaticMethodCallNode.java
index 0228514..96e2e4c 100644
--- a/src/main/java/org/zwobble/couscous/ast/StaticMethodCallNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/StaticMethodCallNode.java
@@ -2,7 +2,7 @@ package org.zwobble.couscous.ast;
 
 import java.util.List;
 
-import org.zwobble.couscous.ast.visitors.ExpressionNodeVisitor;
+import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.values.TypeReference;
 
 import static java.util.Arrays.asList;
@@ -24,7 +24,7 @@ public class StaticMethodCallNode implements ExpressionNode {
     List<ExpressionNode> arguments;
     
     @Override
-    public <T> T accept(ExpressionNodeVisitor<T> visitor) {
+    public <T> T accept(ExpressionNodeMapper<T> visitor) {
         return visitor.visit(this);
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/TernaryConditionalNode.java b/src/main/java/org/zwobble/couscous/ast/TernaryConditionalNode.java
index 8b30024..99b5f60 100644
--- a/src/main/java/org/zwobble/couscous/ast/TernaryConditionalNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/TernaryConditionalNode.java
@@ -1,6 +1,6 @@
 package org.zwobble.couscous.ast;
 
-import org.zwobble.couscous.ast.visitors.ExpressionNodeVisitor;
+import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.values.TypeReference;
 
 import lombok.Value;
@@ -12,7 +12,7 @@ public class TernaryConditionalNode implements ExpressionNode {
     ExpressionNode ifFalse;
     
     @Override
-    public <T> T accept(ExpressionNodeVisitor<T> visitor) {
+    public <T> T accept(ExpressionNodeMapper<T> visitor) {
         return visitor.visit(this);
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/VariableReferenceNode.java b/src/main/java/org/zwobble/couscous/ast/VariableReferenceNode.java
index 5499d50..fe47a84 100644
--- a/src/main/java/org/zwobble/couscous/ast/VariableReferenceNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/VariableReferenceNode.java
@@ -1,6 +1,6 @@
 package org.zwobble.couscous.ast;
 
-import org.zwobble.couscous.ast.visitors.ExpressionNodeVisitor;
+import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.values.TypeReference;
 
 import lombok.Value;
@@ -14,7 +14,7 @@ public class VariableReferenceNode implements ExpressionNode {
     VariableDeclaration referent;
 
     @Override
-    public <T> T accept(ExpressionNodeVisitor<T> visitor) {
+    public <T> T accept(ExpressionNodeMapper<T> visitor) {
         return visitor.visit(this);
     }
     
diff --git a/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeVisitor.java b/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeMapper.java
index c47b942..2be2894 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeVisitor.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeMapper.java
@@ -7,7 +7,7 @@ import org.zwobble.couscous.ast.StaticMethodCallNode;
 import org.zwobble.couscous.ast.TernaryConditionalNode;
 import org.zwobble.couscous.ast.VariableReferenceNode;
 
-public interface ExpressionNodeVisitor<T> {
+public interface ExpressionNodeMapper<T> {
     T visit(LiteralNode literal);
     T visit(VariableReferenceNode variableReference);
     T visit(AssignmentNode assignment);
diff --git a/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitor.java b/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitor.java
new file mode 100644
index 0000000..014b48e
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitor.java
@@ -0,0 +1,29 @@
+package org.zwobble.couscous.ast.visitors;
+
+import org.zwobble.couscous.ast.AssignmentNode;
+import org.zwobble.couscous.ast.ClassNode;
+import org.zwobble.couscous.ast.ExpressionStatementNode;
+import org.zwobble.couscous.ast.LiteralNode;
+import org.zwobble.couscous.ast.LocalVariableDeclarationNode;
+import org.zwobble.couscous.ast.MethodCallNode;
+import org.zwobble.couscous.ast.MethodNode;
+import org.zwobble.couscous.ast.ReturnNode;
+import org.zwobble.couscous.ast.StaticMethodCallNode;
+import org.zwobble.couscous.ast.TernaryConditionalNode;
+import org.zwobble.couscous.ast.VariableReferenceNode;
+
+public interface NodeVisitor {
+    void visit(LiteralNode literal);
+    void visit(VariableReferenceNode variableReference);
+    void visit(AssignmentNode assignment);
+    void visit(TernaryConditionalNode ternaryConditional);
+    void visit(MethodCallNode methodCall);
+    void visit(StaticMethodCallNode staticMethodCall);
+
+    void visit(ReturnNode returnNode);
+    void visit(ExpressionStatementNode expressionStatement);
+    void visit(LocalVariableDeclarationNode localVariableDeclaration);
+    
+    void visit(ClassNode classNode);
+    void visit(MethodNode methodNode);
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitorWithEmptyDefaults.java b/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitorWithEmptyDefaults.java
new file mode 100644
index 0000000..3a58614
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitorWithEmptyDefaults.java
@@ -0,0 +1,59 @@
+package org.zwobble.couscous.ast.visitors;
+
+import org.zwobble.couscous.ast.AssignmentNode;
+import org.zwobble.couscous.ast.ClassNode;
+import org.zwobble.couscous.ast.ExpressionStatementNode;
+import org.zwobble.couscous.ast.LiteralNode;
+import org.zwobble.couscous.ast.LocalVariableDeclarationNode;
+import org.zwobble.couscous.ast.MethodCallNode;
+import org.zwobble.couscous.ast.MethodNode;
+import org.zwobble.couscous.ast.ReturnNode;
+import org.zwobble.couscous.ast.StaticMethodCallNode;
+import org.zwobble.couscous.ast.TernaryConditionalNode;
+import org.zwobble.couscous.ast.VariableReferenceNode;
+
+public interface NodeVisitorWithEmptyDefaults extends NodeVisitor {
+    @Override
+    default void visit(LiteralNode literal) {
+    }
+    
+    @Override
+    default void visit(VariableReferenceNode variableReference) {
+    }
+    
+    @Override
+    default void visit(AssignmentNode assignment) {
+    }
+    
+    @Override
+    default void visit(TernaryConditionalNode ternaryConditional) {
+    }
+    
+    @Override
+    default void visit(MethodCallNode methodCall) {
+    }
+    
+    @Override
+    default void visit(StaticMethodCallNode staticMethodCall) {
+    }
+
+    @Override
+    default void visit(ReturnNode returnNode) {
+    }
+    
+    @Override
+    default void visit(ExpressionStatementNode expressionStatement) {
+    }
+    
+    @Override
+    default void visit(LocalVariableDeclarationNode localVariableDeclaration) {
+    }
+    
+    @Override
+    default void visit(ClassNode classNode) {
+    }
+    
+    @Override
+    default void visit(MethodNode methodNode) {
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitors.java b/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitors.java
new file mode 100644
index 0000000..88c6e10
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitors.java
@@ -0,0 +1,97 @@
+package org.zwobble.couscous.ast.visitors;
+
+import org.zwobble.couscous.ast.AssignmentNode;
+import org.zwobble.couscous.ast.ClassNode;
+import org.zwobble.couscous.ast.ExpressionStatementNode;
+import org.zwobble.couscous.ast.LiteralNode;
+import org.zwobble.couscous.ast.LocalVariableDeclarationNode;
+import org.zwobble.couscous.ast.MethodCallNode;
+import org.zwobble.couscous.ast.MethodNode;
+import org.zwobble.couscous.ast.Node;
+import org.zwobble.couscous.ast.ReturnNode;
+import org.zwobble.couscous.ast.StaticMethodCallNode;
+import org.zwobble.couscous.ast.TernaryConditionalNode;
+import org.zwobble.couscous.ast.VariableReferenceNode;
+
+import lombok.val;
+
+public class NodeVisitors {
+    public static void visitAll(Node node, NodeVisitor visitor) {
+        node.accept(new NodeVisitor() {
+            @Override
+            public void visit(LiteralNode literal) {
+                visitor.visit(literal);
+            }
+            
+            @Override
+            public void visit(VariableReferenceNode variableReference) {
+                visitor.visit(variableReference);
+            }
+            
+            @Override
+            public void visit(AssignmentNode assignment) {
+                visitor.visit(assignment);
+                assignment.getValue().accept(this);
+                visit(assignment.getTarget());
+            }
+            
+            @Override
+            public void visit(TernaryConditionalNode ternaryConditional) {
+                visitor.visit(ternaryConditional);
+                ternaryConditional.getCondition().accept(this);
+                ternaryConditional.getIfTrue().accept(this);
+                ternaryConditional.getIfFalse().accept(this);
+            }
+            
+            @Override
+            public void visit(MethodCallNode methodCall) {
+                visitor.visit(methodCall);
+                methodCall.getReceiver().accept(this);
+                for (val argument : methodCall.getArguments()) {
+                    argument.accept(this);
+                }
+            }
+            
+            @Override
+            public void visit(StaticMethodCallNode staticMethodCall) {
+                visitor.visit(staticMethodCall);
+                for (val argument : staticMethodCall.getArguments()) {
+                    argument.accept(this);
+                }
+            }
+            
+            @Override
+            public void visit(ReturnNode returnNode) {
+                visitor.visit(returnNode);
+                returnNode.getValue().accept(this);
+            }
+            
+            @Override
+            public void visit(ExpressionStatementNode expressionStatement) {
+                visitor.visit(expressionStatement);
+                expressionStatement.getExpression().accept(this);
+            }
+            
+            @Override
+            public void visit(LocalVariableDeclarationNode localVariableDeclaration) {
+                visitor.visit(localVariableDeclaration);
+                localVariableDeclaration.getInitialValue().accept(this);
+            }
+
+            @Override
+            public void visit(ClassNode classNode) {
+                visitor.visit(classNode);
+                for (val method : classNode.getMethods()) {
+                    method.accept(this);
+                }
+            }
+
+            @Override
+            public void visit(MethodNode methodNode) {
+                for (val statement : methodNode.getBody()) {
+                    statement.accept(this);
+                }
+            }
+        });
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/visitors/StatementNodeVisitor.java b/src/main/java/org/zwobble/couscous/ast/visitors/StatementNodeMapper.java
index 620f6f8..4bae481 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/StatementNodeVisitor.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/StatementNodeMapper.java
@@ -4,7 +4,7 @@ import org.zwobble.couscous.ast.ExpressionStatementNode;
 import org.zwobble.couscous.ast.LocalVariableDeclarationNode;
 import org.zwobble.couscous.ast.ReturnNode;
 
-public interface StatementNodeVisitor<T> {
+public interface StatementNodeMapper<T> {
     T visit(ReturnNode returnNode);
     T visit(ExpressionStatementNode expressionStatement);
     T visit(LocalVariableDeclarationNode localVariableDeclaration);
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 cf48ba0..551abcb 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
@@ -1,6 +1,8 @@
 package org.zwobble.couscous.backends.python;
 
 import java.util.List;
+import java.util.Set;
+import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
 import org.zwobble.couscous.ast.AssignmentNode;
@@ -16,11 +18,14 @@ import org.zwobble.couscous.ast.StatementNode;
 import org.zwobble.couscous.ast.StaticMethodCallNode;
 import org.zwobble.couscous.ast.TernaryConditionalNode;
 import org.zwobble.couscous.ast.VariableReferenceNode;
-import org.zwobble.couscous.ast.visitors.ExpressionNodeVisitor;
-import org.zwobble.couscous.ast.visitors.StatementNodeVisitor;
+import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
+import org.zwobble.couscous.ast.visitors.NodeVisitorWithEmptyDefaults;
+import org.zwobble.couscous.ast.visitors.NodeVisitors;
+import org.zwobble.couscous.ast.visitors.StatementNodeMapper;
 import org.zwobble.couscous.backends.python.ast.PythonBlock;
 import org.zwobble.couscous.backends.python.ast.PythonExpressionNode;
 import org.zwobble.couscous.backends.python.ast.PythonFunctionDefinitionNode;
+import org.zwobble.couscous.backends.python.ast.PythonImportNode;
 import org.zwobble.couscous.backends.python.ast.PythonModuleNode;
 import org.zwobble.couscous.backends.python.ast.PythonStatementNode;
 import org.zwobble.couscous.backends.python.ast.PythonVariableReferenceNode;
@@ -31,6 +36,11 @@ import org.zwobble.couscous.values.PrimitiveValueVisitor;
 import org.zwobble.couscous.values.StringValue;
 import org.zwobble.couscous.values.UnitValue;
 
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Iterators;
+
+import static com.google.common.collect.Iterators.singletonIterator;
 import static java.util.Arrays.asList;
 import static org.zwobble.couscous.backends.python.ast.PythonAssignmentNode.pythonAssignment;
 import static org.zwobble.couscous.backends.python.ast.PythonAttributeAccessNode.pythonAttributeAccess;
@@ -44,18 +54,37 @@ import static org.zwobble.couscous.backends.python.ast.PythonModuleNode.pythonMo
 import static org.zwobble.couscous.backends.python.ast.PythonReturnNode.pythonReturn;
 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.util.ExtraLists.foldLeft;
 
 import lombok.val;
 
 public class PythonCodeGenerator {
     public static PythonModuleNode generateCode(ClassNode classNode) {
+        val imports = findImports(classNode).stream()
+            .map(PythonImportNode::pythonImport)
+            .iterator();
+        
         val pythonBody = classNode.getMethods()
             .stream()
             .map(PythonCodeGenerator::generateFunction)
             .collect(Collectors.toList());
         
         val pythonClass = pythonClass(classNode.getLocalName(), pythonBody);
-        return pythonModule(asList(pythonClass));
+        
+        return pythonModule(ImmutableList.copyOf(Iterators.concat(
+            imports,
+            singletonIterator(pythonClass))));
+    }
+    
+    private static Set<String> findImports(ClassNode classNode) {
+        val imports = ImmutableSet.<String>builder();
+        NodeVisitors.visitAll(classNode, new NodeVisitorWithEmptyDefaults() {
+            @Override
+            public void visit(StaticMethodCallNode staticMethodCall) {
+                imports.add(staticMethodCall.getClassName());
+            }
+        });
+        return imports.build();
     }
     
     public static PythonExpressionNode generateCode(PrimitiveValue value) {
@@ -99,7 +128,7 @@ public class PythonCodeGenerator {
         return statement.accept(new StatementGenerator());
     }
     
-    private static class StatementGenerator implements StatementNodeVisitor<PythonStatementNode> {
+    private static class StatementGenerator implements StatementNodeMapper<PythonStatementNode> {
         @Override
         public PythonStatementNode visit(ReturnNode returnNode) {
             return pythonReturn(generateExpression(returnNode.getValue()));
@@ -131,7 +160,7 @@ public class PythonCodeGenerator {
     
     private static final ExpressionGenerator EXPRESSION_GENERATOR = new ExpressionGenerator();
     
-    private static class ExpressionGenerator implements ExpressionNodeVisitor<PythonExpressionNode> {
+    private static class ExpressionGenerator implements ExpressionNodeMapper<PythonExpressionNode> {
         @Override
         public PythonExpressionNode visit(LiteralNode literal) {
             return generateCode(literal.getValue());
@@ -171,16 +200,36 @@ public class PythonCodeGenerator {
             }
         }
 
+        @Override
+        public PythonExpressionNode visit(StaticMethodCallNode staticMethodCall) {
+            val className = staticMethodCall.getClassName();
+            val moduleParts = asList(className.split(Pattern.quote(".")));
+            
+            val module = foldLeft(
+                moduleParts,
+                part -> (PythonExpressionNode)pythonVariableReference(part),
+                (parent, part) -> pythonAttributeAccess(parent, part));
+            
+            val classReference = pythonAttributeAccess(
+                module,
+                className.substring(className.lastIndexOf(".") + 1));
+
+            val methodReference = pythonAttributeAccess(
+                classReference,
+                staticMethodCall.getMethodName());
+            
+            val arguments = staticMethodCall.getArguments().stream()
+                .map(PythonCodeGenerator::generateExpression)
+                .collect(Collectors.toList());;
+                
+            return pythonCall(methodReference, arguments);
+        }
+
         private List<PythonExpressionNode> generateArguments(MethodCallNode methodCall) {
             return methodCall.getArguments().stream()
                 .map(PythonCodeGenerator::generateExpression)
                 .collect(Collectors.toList());
         }
-
-        @Override
-        public PythonExpressionNode visit(StaticMethodCallNode staticMethodCall) {
-            throw new UnsupportedOperationException();
-        }
     }
     
     private static boolean isPrimitive(ExpressionNode value) {
diff --git a/src/main/java/org/zwobble/couscous/backends/python/PythonCompiler.java b/src/main/java/org/zwobble/couscous/backends/python/PythonCompiler.java
index b38bc73..a54f037 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/PythonCompiler.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/PythonCompiler.java
@@ -15,20 +15,35 @@ import lombok.SneakyThrows;
 import lombok.val;
 
 public class PythonCompiler {
-    public void compile(List<ClassNode> classes, Path path) {
+    private final Path root;
+
+    public PythonCompiler(Path root) {
+        this.root = root;
+    }
+    
+    public void compile(List<ClassNode> classes) {
         for (val classNode : classes) {
-            compileClass(classNode, pathForClass(classNode, path));
+            compileClass(classNode);
         }
+        writeClass("java.lang.Integer",
+            "class Integer(object):\n" +
+            "    def parseInt(value):\n" +
+            "        return int(value)"
+        );
+    }
+
+    private Path pathForClass(String className) {
+        return root.resolve(className.replace(".", File.separator) + ".py");
     }
 
-    private Path pathForClass(ClassNode classNode, Path path) {
-        return path.resolve(classNode.getName().replace(".", File.separator) + ".py");
+    private void compileClass(ClassNode classNode) {
+        writeClass(classNode.getName(), serialize(generateCode(classNode)));
     }
 
     @SneakyThrows
-    private void compileClass(ClassNode classNode, Path path) {
+    private void writeClass(String name, String contents) {
+        val path = pathForClass(name);
         Files.createDirectories(path.getParent());
-        Files.write(path, asList(serialize(generateCode(classNode))));
-        
+        Files.write(path, asList(contents));
     }
 }
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 0bd71f7..9c82b5d 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/PythonSerializer.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/PythonSerializer.java
@@ -13,6 +13,7 @@ import org.zwobble.couscous.backends.python.ast.PythonConditionalExpressionNode;
 import org.zwobble.couscous.backends.python.ast.PythonExpressionNode;
 import org.zwobble.couscous.backends.python.ast.PythonFunctionDefinitionNode;
 import org.zwobble.couscous.backends.python.ast.PythonGetSliceNode;
+import org.zwobble.couscous.backends.python.ast.PythonImportNode;
 import org.zwobble.couscous.backends.python.ast.PythonIntegerLiteralNode;
 import org.zwobble.couscous.backends.python.ast.PythonModuleNode;
 import org.zwobble.couscous.backends.python.ast.PythonNode;
@@ -160,6 +161,15 @@ public class PythonSerializer implements PythonNodeVisitor {
         });
     }
 
+    @Override
+    public void visit(PythonImportNode importNode) {
+        writer.writeStatement(() -> {
+            writer.writeKeyword("import");
+            writer.writeSpace();
+            writer.writeIdentifier(importNode.getName());
+        });
+    }
+
     private void writeParenthesised(PythonExpressionNode expression) {
         writer.writeSymbol("(");
         write(expression);
diff --git a/src/main/java/org/zwobble/couscous/backends/python/ast/PythonImportNode.java b/src/main/java/org/zwobble/couscous/backends/python/ast/PythonImportNode.java
new file mode 100644
index 0000000..2d38004
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/backends/python/ast/PythonImportNode.java
@@ -0,0 +1,15 @@
+package org.zwobble.couscous.backends.python.ast;
+
+import org.zwobble.couscous.backends.python.ast.visitors.PythonNodeVisitor;
+
+import lombok.Value;
+
+@Value(staticConstructor="pythonImport")
+public class PythonImportNode implements PythonStatementNode {
+    String name;
+    
+    @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 29d6108..7632342 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
@@ -8,6 +8,7 @@ import org.zwobble.couscous.backends.python.ast.PythonClassNode;
 import org.zwobble.couscous.backends.python.ast.PythonConditionalExpressionNode;
 import org.zwobble.couscous.backends.python.ast.PythonFunctionDefinitionNode;
 import org.zwobble.couscous.backends.python.ast.PythonGetSliceNode;
+import org.zwobble.couscous.backends.python.ast.PythonImportNode;
 import org.zwobble.couscous.backends.python.ast.PythonIntegerLiteralNode;
 import org.zwobble.couscous.backends.python.ast.PythonModuleNode;
 import org.zwobble.couscous.backends.python.ast.PythonPassNode;
@@ -30,6 +31,7 @@ public interface PythonNodeVisitor {
     void visit(PythonClassNode pythonClass);
     void visit(PythonFunctionDefinitionNode functionDefinition);
     void visit(PythonAssignmentNode assignment);
+    void visit(PythonImportNode importNode);
 
     void visit(PythonModuleNode module);
 
diff --git a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
index c2eeb59..9f183ec 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
@@ -10,14 +10,14 @@ import org.zwobble.couscous.ast.MethodCallNode;
 import org.zwobble.couscous.ast.StaticMethodCallNode;
 import org.zwobble.couscous.ast.TernaryConditionalNode;
 import org.zwobble.couscous.ast.VariableReferenceNode;
-import org.zwobble.couscous.ast.visitors.ExpressionNodeVisitor;
+import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.interpreter.values.BooleanInterpreterValue;
 import org.zwobble.couscous.interpreter.values.InterpreterValue;
 import org.zwobble.couscous.interpreter.values.InterpreterValues;
 
 import lombok.val;
 
-public class Evaluator implements ExpressionNodeVisitor<InterpreterValue> {
+public class Evaluator implements ExpressionNodeMapper<InterpreterValue> {
     public static InterpreterValue eval(Environment environment, ExpressionNode expression) {
         return new Evaluator(environment).eval(expression);
     }
diff --git a/src/main/java/org/zwobble/couscous/interpreter/Executor.java b/src/main/java/org/zwobble/couscous/interpreter/Executor.java
index 4ed4a04..93adf16 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Executor.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Executor.java
@@ -10,7 +10,7 @@ import org.zwobble.couscous.ast.MethodNode;
 import org.zwobble.couscous.ast.ReturnNode;
 import org.zwobble.couscous.ast.StatementNode;
 import org.zwobble.couscous.ast.VariableNode;
-import org.zwobble.couscous.ast.visitors.StatementNodeVisitor;
+import org.zwobble.couscous.ast.visitors.StatementNodeMapper;
 import org.zwobble.couscous.interpreter.values.InterpreterValue;
 import org.zwobble.couscous.interpreter.values.UnitInterpreterValue;
 
@@ -18,7 +18,7 @@ import static org.zwobble.couscous.interpreter.Evaluator.eval;
 
 import lombok.val;
 
-public class Executor implements StatementNodeVisitor<Optional<InterpreterValue>> {
+public class Executor implements StatementNodeMapper<Optional<InterpreterValue>> {
     public static InterpreterValue callMethod(Environment environment, MethodNode method, Arguments arguments) {
         val innerEnvironment = buildEnvironment(environment, method, arguments);
       
@@ -49,7 +49,7 @@ public class Executor implements StatementNodeVisitor<Optional<InterpreterValue>
     
     private static Stream<VariableNode> findDeclarations(List<StatementNode> body) {
         return body.stream()
-            .flatMap(statement -> statement.accept(new StatementNodeVisitor<Stream<VariableNode>>() {
+            .flatMap(statement -> statement.accept(new StatementNodeMapper<Stream<VariableNode>>() {
                 @Override
                 public Stream<VariableNode> visit(ReturnNode returnNode) {
                     return Stream.empty();
diff --git a/src/main/java/org/zwobble/couscous/util/ExtraLists.java b/src/main/java/org/zwobble/couscous/util/ExtraLists.java
new file mode 100644
index 0000000..b3c017f
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/util/ExtraLists.java
@@ -0,0 +1,18 @@
+package org.zwobble.couscous.util;
+
+import java.util.List;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+
+public class ExtraLists {
+    public static <T, R> R foldLeft(
+            List<T> list,
+            Function<T, R> initialValue,
+            BiFunction<R, T, R> function) {
+        R accumulator = initialValue.apply(list.get(0));
+        for (int index = 1; index < list.size(); index++) {
+            accumulator = function.apply(accumulator, list.get(index));
+        }
+        return accumulator;
+    }
+}