Support equality on reference types

6 files changed, 92 insertions, 8 deletions

diff --git a/src/main/java/org/zwobble/couscous/backends/python/PrimitiveMethods.java b/src/main/java/org/zwobble/couscous/backends/python/PrimitiveMethods.java
index c6aa62d..6605fc9 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/PrimitiveMethods.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/PrimitiveMethods.java
@@ -9,6 +9,7 @@ import org.zwobble.couscous.backends.python.ast.PythonExpressionNode;
 import org.zwobble.couscous.backends.python.ast.PythonNotNode;
 import org.zwobble.couscous.values.BooleanValue;
 import org.zwobble.couscous.values.IntegerValue;
+import org.zwobble.couscous.values.InternalCouscousValue;
 import org.zwobble.couscous.values.StringValue;
 
 import com.google.common.collect.ImmutableMap;
@@ -16,6 +17,7 @@ import com.google.common.collect.ImmutableMap.Builder;
 
 import static java.util.Arrays.asList;
 import static org.zwobble.couscous.backends.python.ast.PythonAttributeAccessNode.pythonAttributeAccess;
+import static org.zwobble.couscous.backends.python.ast.PythonBinaryOperation.pythonIs;
 import static org.zwobble.couscous.backends.python.ast.PythonCallNode.pythonCall;
 import static org.zwobble.couscous.backends.python.ast.PythonGetSliceNode.pythonGetSlice;
 import static org.zwobble.couscous.backends.python.ast.PythonVariableReferenceNode.pythonVariableReference;
@@ -90,6 +92,18 @@ public class PrimitiveMethods {
             .put(IntegerValue.REF, INT_METHODS)
             .build();
     
+    private static final Map<String, PrimitiveStaticMethodGenerator> INTERNAL_METHODS =
+        ImmutableMap.<String, PrimitiveStaticMethodGenerator>builder()
+        
+            .put("same", arguments -> pythonIs(arguments.get(0), arguments.get(1)))
+            
+            .build();
+    
+    private static final Map<TypeName, Map<String, PrimitiveStaticMethodGenerator>> STATIC_METHODS = 
+        ImmutableMap.<TypeName, Map<String, PrimitiveStaticMethodGenerator>>builder()
+            .put(InternalCouscousValue.REF, INTERNAL_METHODS)
+            .build();
+    
     public static boolean isPrimitive(TypeName type) {
         return METHODS.containsKey(type);
     }
@@ -103,4 +117,14 @@ public class PrimitiveMethods {
     public interface PrimitiveMethodGenerator {
         PythonExpressionNode generate(PythonExpressionNode receiver, List<PythonExpressionNode> arguments);
     }
+
+    public static Optional<PrimitiveStaticMethodGenerator> getPrimitiveStaticMethod(TypeName type, String methodName) {
+        return Optional.ofNullable(STATIC_METHODS.get(type))
+            .flatMap(methodsForType -> Optional.ofNullable(methodsForType.get(methodName)));
+    }
+    
+    @FunctionalInterface
+    public interface PrimitiveStaticMethodGenerator {
+        PythonExpressionNode generate(List<PythonExpressionNode> arguments);
+    }
 }
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 54d56ed..fb1851c 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
@@ -29,6 +29,7 @@ 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.PrimitiveMethods.PrimitiveMethodGenerator;
+import org.zwobble.couscous.backends.python.ast.PythonAttributeAccessNode;
 import org.zwobble.couscous.backends.python.ast.PythonBlock;
 import org.zwobble.couscous.backends.python.ast.PythonClassNode;
 import org.zwobble.couscous.backends.python.ast.PythonExpressionNode;
@@ -39,6 +40,7 @@ import org.zwobble.couscous.backends.python.ast.PythonStatementNode;
 import org.zwobble.couscous.backends.python.ast.PythonVariableReferenceNode;
 import org.zwobble.couscous.values.BooleanValue;
 import org.zwobble.couscous.values.IntegerValue;
+import org.zwobble.couscous.values.InternalCouscousValue;
 import org.zwobble.couscous.values.PrimitiveValue;
 import org.zwobble.couscous.values.PrimitiveValueVisitor;
 import org.zwobble.couscous.values.StringValue;
@@ -92,7 +94,9 @@ public class PythonCodeGenerator {
     
     private static Stream<PythonImportNode> generateImports(ClassNode classNode) {
         Set<TypeName> classes = findReferencedClasses(classNode);
-        return classes.stream().map(name -> pythonImport(importPathToRoot(classNode) + name.getQualifiedName(), asList(pythonImportAlias(name.getSimpleName()))));
+        return classes.stream()
+            .filter(name -> !name.equals(InternalCouscousValue.REF))
+            .map(name -> pythonImport(importPathToRoot(classNode) + name.getQualifiedName(), asList(pythonImportAlias(name.getSimpleName()))));
     }
 
     private static String importPathToRoot(ClassNode classNode) {
@@ -243,11 +247,14 @@ public class PythonCodeGenerator {
         
         @Override
         public PythonExpressionNode visit(StaticMethodCallNode staticMethodCall) {
-            final org.zwobble.couscous.ast.TypeName className = staticMethodCall.getClassName();
-            final org.zwobble.couscous.backends.python.ast.PythonVariableReferenceNode classReference = pythonVariableReference(className.getSimpleName());
-            final org.zwobble.couscous.backends.python.ast.PythonAttributeAccessNode methodReference = pythonAttributeAccess(classReference, staticMethodCall.getMethodName());
-            final java.util.List<org.zwobble.couscous.backends.python.ast.PythonExpressionNode> arguments = generateExpressions(staticMethodCall.getArguments());
-            return pythonCall(methodReference, arguments);
+            TypeName className = staticMethodCall.getClassName();
+            PythonVariableReferenceNode classReference = pythonVariableReference(className.getSimpleName());
+            PythonAttributeAccessNode methodReference = pythonAttributeAccess(classReference, staticMethodCall.getMethodName());
+            List<PythonExpressionNode> arguments = generateExpressions(staticMethodCall.getArguments());
+            
+            return PrimitiveMethods.getPrimitiveStaticMethod(className, staticMethodCall.getMethodName())
+                .map(generator -> generator.generate(arguments))
+                .orElseGet(() -> pythonCall(methodReference, arguments));                
         }
         
         @Override
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 c8f9932..d077736 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/PythonCompiler.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/PythonCompiler.java
@@ -17,7 +17,9 @@ import static org.zwobble.couscous.backends.python.PythonSerializer.serialize;
 
 public class PythonCompiler {
     private static final List<String> RUNTIME_FILES = asList(
-        "java.lang.Integer", "_couscous");
+        "java.lang.Object",
+        "java.lang.Integer",
+        "_couscous");
     
     private final Path root;
     private final String packageName;
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 eadb545..2fb341f 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/PythonSerializer.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/PythonSerializer.java
@@ -4,6 +4,7 @@ import java.util.List;
 import java.util.function.Consumer;
 import org.zwobble.couscous.backends.python.ast.PythonAssignmentNode;
 import org.zwobble.couscous.backends.python.ast.PythonAttributeAccessNode;
+import org.zwobble.couscous.backends.python.ast.PythonBinaryOperation;
 import org.zwobble.couscous.backends.python.ast.PythonBlock;
 import org.zwobble.couscous.backends.python.ast.PythonBooleanLiteralNode;
 import org.zwobble.couscous.backends.python.ast.PythonCallNode;
@@ -34,7 +35,7 @@ public class PythonSerializer implements PythonNodeVisitor {
         return writer.asString();
     }
     
-    private PythonWriter writer;
+    private final PythonWriter writer;
     
     private PythonSerializer(PythonWriter writer) {
         this.writer = writer;
@@ -111,6 +112,15 @@ public class PythonSerializer implements PythonNodeVisitor {
         writer.writeSpace();
         writeParenthesised(notOperation.getOperand());
     }
+
+    @Override
+    public void visit(PythonBinaryOperation operation) {
+        writeParenthesised(operation.getLeft());
+        writer.writeSpace();
+        writer.writeKeyword(operation.getOperator());
+        writer.writeSpace();
+        writeParenthesised(operation.getRight());
+    }
     
     @Override
     public void visit(PythonReturnNode pythonReturn) {
diff --git a/src/main/java/org/zwobble/couscous/backends/python/ast/PythonBinaryOperation.java b/src/main/java/org/zwobble/couscous/backends/python/ast/PythonBinaryOperation.java
new file mode 100644
index 0000000..1fc87c3
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/backends/python/ast/PythonBinaryOperation.java
@@ -0,0 +1,39 @@
+package org.zwobble.couscous.backends.python.ast;
+
+import org.zwobble.couscous.backends.python.ast.visitors.PythonNodeVisitor;
+
+public class PythonBinaryOperation implements PythonExpressionNode {
+    public static PythonExpressionNode pythonIs(PythonExpressionNode left, PythonExpressionNode right) {
+        return new PythonBinaryOperation("is", left, right);
+    }
+    
+    private final String operator;
+    private final PythonExpressionNode left;
+    private final PythonExpressionNode right;
+
+    public PythonBinaryOperation(
+            String operator,
+            PythonExpressionNode left,
+            PythonExpressionNode right) {
+        this.operator = operator;
+        this.left = left;
+        this.right = right;
+    }
+    
+    public String getOperator() {
+        return operator;
+    }
+    
+    public PythonExpressionNode getLeft() {
+        return left;
+    }
+    
+    public PythonExpressionNode getRight() {
+        return right;
+    }
+
+    @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 59a1fe9..a1ed7d5 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
@@ -2,6 +2,7 @@ package org.zwobble.couscous.backends.python.ast.visitors;
 
 import org.zwobble.couscous.backends.python.ast.PythonAssignmentNode;
 import org.zwobble.couscous.backends.python.ast.PythonAttributeAccessNode;
+import org.zwobble.couscous.backends.python.ast.PythonBinaryOperation;
 import org.zwobble.couscous.backends.python.ast.PythonBooleanLiteralNode;
 import org.zwobble.couscous.backends.python.ast.PythonCallNode;
 import org.zwobble.couscous.backends.python.ast.PythonClassNode;
@@ -27,6 +28,7 @@ public interface PythonNodeVisitor {
     void visit(PythonCallNode call);
     void visit(PythonGetSliceNode getSlice);
     void visit(PythonNotNode notOperation);
+    void visit(PythonBinaryOperation operation);
     
     void visit(PythonReturnNode pythonReturn);
     void visit(PythonPassNode pass);