Support instanceof in C# backend

16 files changed, 137 insertions, 9 deletions

diff --git a/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java b/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java
index 37bd436..4c104f3 100644
--- a/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java
@@ -58,6 +58,11 @@ public interface ExpressionNode extends Node {
             }
 
             @Override
+            public T visit(InstanceOfNode instanceOf) {
+                return visitor.visit(instanceOf);
+            }
+
+            @Override
             public T visit(FieldAccessNode fieldAccess) {
                 return visitor.visit(fieldAccess);
             }
diff --git a/src/main/java/org/zwobble/couscous/ast/InstanceOfNode.java b/src/main/java/org/zwobble/couscous/ast/InstanceOfNode.java
new file mode 100644
index 0000000..21f823b
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/InstanceOfNode.java
@@ -0,0 +1,69 @@
+package org.zwobble.couscous.ast;
+
+import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
+import org.zwobble.couscous.ast.visitors.NodeTransformer;
+import org.zwobble.couscous.types.ScalarType;
+import org.zwobble.couscous.types.Type;
+import org.zwobble.couscous.types.Types;
+
+public class InstanceOfNode implements ExpressionNode {
+    private final ExpressionNode left;
+    private final ScalarType right;
+
+    public InstanceOfNode(ExpressionNode left, ScalarType right) {
+        this.left = left;
+        this.right = right;
+    }
+
+    public ExpressionNode getLeft() {
+        return left;
+    }
+
+    public ScalarType getRight() {
+        return right;
+    }
+
+    @Override
+    public Type getType() {
+        return Types.BOOLEAN;
+    }
+
+    @Override
+    public <T> T accept(ExpressionNodeMapper<T> visitor) {
+        return visitor.visit(this);
+    }
+
+    @Override
+    public ExpressionNode transform(NodeTransformer transformer) {
+        return new InstanceOfNode(
+            transformer.transformExpression(left),
+            transformer.transform(right));
+    }
+
+    @Override
+    public String toString() {
+        return "InstanceOfNode(" +
+            "left=" + left +
+            ", right=" + right +
+            ')';
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        InstanceOfNode that = (InstanceOfNode) o;
+
+        if (!left.equals(that.left)) return false;
+        return right.equals(that.right);
+
+    }
+
+    @Override
+    public int hashCode() {
+        int result = left.hashCode();
+        result = 31 * result + right.hashCode();
+        return result;
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/Node.java b/src/main/java/org/zwobble/couscous/ast/Node.java
index 240afa4..7bea8b9 100644
--- a/src/main/java/org/zwobble/couscous/ast/Node.java
+++ b/src/main/java/org/zwobble/couscous/ast/Node.java
@@ -61,6 +61,12 @@ public interface Node {
             }
 
             @Override
+            public Void visit(InstanceOfNode instanceOf) {
+                visitor.visit(instanceOf);
+                return null;
+            }
+
+            @Override
             public Void visit(FieldAccessNode fieldAccess) {
                 visitor.visit(fieldAccess);
                 return null;
diff --git a/src/main/java/org/zwobble/couscous/ast/Operations.java b/src/main/java/org/zwobble/couscous/ast/Operations.java
index ca7483f..0ef9b88 100644
--- a/src/main/java/org/zwobble/couscous/ast/Operations.java
+++ b/src/main/java/org/zwobble/couscous/ast/Operations.java
@@ -4,7 +4,6 @@ import org.zwobble.couscous.types.ScalarType;
 import org.zwobble.couscous.types.Types;
 import org.zwobble.couscous.values.InternalCouscousValue;
 
-import static org.zwobble.couscous.ast.LiteralNode.literal;
 import static org.zwobble.couscous.ast.MethodCallNode.staticMethodCall;
 import static org.zwobble.couscous.ast.TypeCoercionNode.typeCoercion;
 import static org.zwobble.couscous.util.ExtraLists.list;
@@ -93,6 +92,6 @@ public class Operations {
     }
 
     public static ExpressionNode instanceOf(ExpressionNode value, ScalarType type) {
-        return booleanOperation(Operator.INSTANCE_OF, value, literal(type));
+        return new InstanceOfNode(value, type);
     }
 }
diff --git a/src/main/java/org/zwobble/couscous/ast/Operator.java b/src/main/java/org/zwobble/couscous/ast/Operator.java
index 9dc197b..a77a135 100644
--- a/src/main/java/org/zwobble/couscous/ast/Operator.java
+++ b/src/main/java/org/zwobble/couscous/ast/Operator.java
@@ -16,9 +16,7 @@ public enum Operator {
     GREATER_THAN(">", true, OperatorType.INFIX),
     GREATER_THAN_OR_EQUAL(">=", true, OperatorType.INFIX),
     LESS_THAN("<", true, OperatorType.INFIX),
-    LESS_THAN_OR_EQUAL("<=", true, OperatorType.INFIX),
-
-    INSTANCE_OF("instanceof", true, OperatorType.INFIX);
+    LESS_THAN_OR_EQUAL("<=", true, OperatorType.INFIX);
 
     private final String symbol;
     private final boolean isBoolean;
diff --git a/src/main/java/org/zwobble/couscous/ast/structure/NodeStructure.java b/src/main/java/org/zwobble/couscous/ast/structure/NodeStructure.java
index a98728b..a31e438 100644
--- a/src/main/java/org/zwobble/couscous/ast/structure/NodeStructure.java
+++ b/src/main/java/org/zwobble/couscous/ast/structure/NodeStructure.java
@@ -82,6 +82,11 @@ public class NodeStructure {
             }
 
             @Override
+            public Stream<? extends Node> visit(InstanceOfNode instanceOf) {
+                return Stream.of(instanceOf.getLeft());
+            }
+
+            @Override
             public Stream<Node> visit(FieldAccessNode fieldAccess) {
                 return Stream.of(fieldAccess.getLeft());
             }
diff --git a/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeMapper.java b/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeMapper.java
index 2c8ed24..acc972a 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeMapper.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeMapper.java
@@ -12,6 +12,7 @@ public interface ExpressionNodeMapper<T> {
     T visit(MethodCallNode methodCall);
     T visit(ConstructorCallNode call);
     T visit(OperationNode operation);
+    T visit(InstanceOfNode instanceOf);
     T visit(FieldAccessNode fieldAccess);
     T visit(TypeCoercionNode typeCoercion);
     T visit(CastNode cast);
diff --git a/src/main/java/org/zwobble/couscous/ast/visitors/NodeMapper.java b/src/main/java/org/zwobble/couscous/ast/visitors/NodeMapper.java
index 50855d8..7ceef06 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/NodeMapper.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/NodeMapper.java
@@ -12,6 +12,7 @@ public interface NodeMapper<T> {
     T visit(MethodCallNode methodCall);
     T visit(ConstructorCallNode call);
     T visit(OperationNode operation);
+    T visit(InstanceOfNode instanceOf);
     T visit(FieldAccessNode fieldAccess);
     T visit(TypeCoercionNode typeCoercion);
     T visit(CastNode cast);
diff --git a/src/main/java/org/zwobble/couscous/ast/visitors/NodeMapperWithDefault.java b/src/main/java/org/zwobble/couscous/ast/visitors/NodeMapperWithDefault.java
index 9fd2617..f98fb1b 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/NodeMapperWithDefault.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/NodeMapperWithDefault.java
@@ -55,6 +55,11 @@ public class NodeMapperWithDefault<T> implements NodeMapper<T> {
     }
 
     @Override
+    public T visit(InstanceOfNode instanceOf) {
+        return defaultValue;
+    }
+
+    @Override
     public T visit(FieldAccessNode fieldAccess) {
         return defaultValue;
     }
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 0edbad9..27116ae 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java
@@ -76,6 +76,11 @@ public class NodeTransformer {
             }
 
             @Override
+            public Node visit(InstanceOfNode instanceOf) {
+                return transformExpression(instanceOf);
+            }
+
+            @Override
             public Node visit(FieldAccessNode fieldAccess) {
                 return transformExpression(fieldAccess);
             }
diff --git a/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitor.java b/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitor.java
index 9ac4a16..648fb5f 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitor.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/NodeVisitor.java
@@ -12,6 +12,7 @@ public interface NodeVisitor {
     void visit(MethodCallNode methodCall);
     void visit(ConstructorCallNode call);
     void visit(OperationNode operation);
+    void visit(InstanceOfNode instanceOf);
     void visit(FieldAccessNode fieldAccess);
     void visit(TypeCoercionNode typeCoercion);
     void visit(CastNode cast);
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 13a4efa..4ec0790 100644
--- a/src/main/java/org/zwobble/couscous/backends/csharp/CsharpSerializer.java
+++ b/src/main/java/org/zwobble/couscous/backends/csharp/CsharpSerializer.java
@@ -261,6 +261,15 @@ public class CsharpSerializer implements NodeVisitor {
         }
     }
 
+    @Override
+    public void visit(InstanceOfNode instanceOf) {
+        writeParenthesized(instanceOf.getLeft(), instanceOf);
+        writer.writeSpace();
+        writer.writeKeyword("is");
+        writer.writeSpace();
+        writeTypeReference(instanceOf.getRight());
+    }
+
     private void writeArguments(List<? extends ExpressionNode> arguments) {
         writer.writeSymbol("(");
         writer.writeCommaSeparated(arguments, this::write);
@@ -763,6 +772,11 @@ public class CsharpSerializer implements NodeVisitor {
             }
 
             @Override
+            public Integer visit(InstanceOfNode instanceOf) {
+                return 9;
+            }
+
+            @Override
             public Integer visit(FieldAccessNode fieldAccess) {
                 return 15;
             }
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 8e99347..504288d 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
@@ -369,6 +369,12 @@ public class PythonCodeGenerator {
         }
 
         @Override
+        public PythonExpressionNode visit(InstanceOfNode instanceOf) {
+            // TODO:
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
         public PythonExpressionNode visit(FieldAccessNode fieldAccess) {
             return pythonAttributeAccess(generateReceiver(fieldAccess.getLeft()), fieldAccess.getFieldName());
         }
diff --git a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
index 4c2a8c3..d7da3b4 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
@@ -121,6 +121,12 @@ public class Evaluator implements ExpressionNodeMapper<InterpreterValue> {
     }
 
     @Override
+    public InterpreterValue visit(InstanceOfNode instanceOf) {
+        // TODO:
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
     public InterpreterValue visit(FieldAccessNode fieldAccess) {
         ReceiverValue left = evalReceiver(fieldAccess.getLeft());
         return left.getField(fieldAccess.getFieldName());
@@ -188,4 +194,4 @@ public class Evaluator implements ExpressionNodeMapper<InterpreterValue> {
             }
         });
     }
-}
\ No newline at end of file
+}
diff --git a/src/test/java/org/zwobble/couscous/tests/ValueObjectTests.java b/src/test/java/org/zwobble/couscous/tests/ValueObjectTests.java
index f6096f8..dbdd483 100644
--- a/src/test/java/org/zwobble/couscous/tests/ValueObjectTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/ValueObjectTests.java
@@ -57,6 +57,7 @@ public class ValueObjectTests {
             {FormalArgumentNode.class},
             {FormalTypeParameterNode.class},
             {IfStatementNode.class},
+            {InstanceOfNode.class},
             {InstanceReceiver.class},
             {InterfaceNode.class},
             {LiteralNode.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 fda3980..3cb723e 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
@@ -26,9 +26,7 @@ import static org.zwobble.couscous.ast.LocalVariableDeclarationNode.localVariabl
 import static org.zwobble.couscous.ast.MethodCallNode.methodCall;
 import static org.zwobble.couscous.ast.MethodCallNode.staticMethodCall;
 import static org.zwobble.couscous.ast.MethodSignature.signature;
-import static org.zwobble.couscous.ast.Operations.integerAdd;
-import static org.zwobble.couscous.ast.Operations.integerMultiply;
-import static org.zwobble.couscous.ast.Operations.not;
+import static org.zwobble.couscous.ast.Operations.*;
 import static org.zwobble.couscous.ast.ReturnNode.returns;
 import static org.zwobble.couscous.ast.TernaryConditionalNode.ternaryConditional;
 import static org.zwobble.couscous.ast.ThisReferenceNode.thisReference;
@@ -196,6 +194,14 @@ public class CsharpSerializerTests {
     }
 
     @Test
+    public void instanceOfIsWrittenUsingIsOperator() {
+        String output = serialize(instanceOf(
+            reference(var(TestIds.ANY_ID, "x", Types.OBJECT)),
+            ScalarType.of("X")));
+        assertEquals("x is X", output);
+    }
+
+    @Test
     public void infixOperationIsBracketedWhenNecessary() {
         assertEquals("1 + 2 * 3", serialize(integerAdd(literal(1), integerMultiply(literal(2), literal(3)))));
         assertEquals("(1 + 2) * 3", serialize(integerMultiply(integerAdd(literal(1), literal(2)), literal(3))));