Add reading of casts

11 files changed, 107 insertions, 0 deletions

diff --git a/src/main/java/org/zwobble/couscous/ast/CastNode.java b/src/main/java/org/zwobble/couscous/ast/CastNode.java
new file mode 100644
index 0000000..e81cd94
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/CastNode.java
@@ -0,0 +1,65 @@
+package org.zwobble.couscous.ast;
+
+import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
+
+import java.util.function.Function;
+
+public class CastNode implements ExpressionNode {
+    public static ExpressionNode cast(ExpressionNode expression, TypeName type) {
+        return new CastNode(expression, type);
+    }
+
+    private final ExpressionNode expression;
+    private final TypeName type;
+
+    private CastNode(ExpressionNode expression, TypeName type) {
+        this.expression = expression;
+        this.type = type;
+    }
+
+    public ExpressionNode getExpression() {
+        return expression;
+    }
+
+    @Override
+    public TypeName getType() {
+        return type;
+    }
+
+    @Override
+    public <T> T accept(ExpressionNodeMapper<T> visitor) {
+        return visitor.visit(this);
+    }
+
+    @Override
+    public ExpressionNode replaceExpressions(Function<ExpressionNode, ExpressionNode> replace) {
+        return new CastNode(replace.apply(expression), type);
+    }
+
+    @Override
+    public String toString() {
+        return "CastNode(" +
+            "expression=" + expression +
+            ", type=" + type +
+            ')';
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        CastNode castNode = (CastNode) o;
+
+        if (!expression.equals(castNode.expression)) return false;
+        return type.equals(castNode.type);
+
+    }
+
+    @Override
+    public int hashCode() {
+        int result = expression.hashCode();
+        result = 31 * result + type.hashCode();
+        return result;
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java b/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java
index ac96c8c..d07b485 100644
--- a/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/ExpressionNode.java
@@ -56,6 +56,11 @@ public interface ExpressionNode extends Node {
             public T visit(TypeCoercionNode typeCoercion) {
                 return visitor.visit(typeCoercion);
             }
+
+            @Override
+            public T visit(CastNode cast) {
+                return visitor.visit(cast);
+            }
         });
     }
 
diff --git a/src/main/java/org/zwobble/couscous/ast/Node.java b/src/main/java/org/zwobble/couscous/ast/Node.java
index a3e7f03..a1a6f91 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(CastNode cast) {
+                visitor.visit(cast);
+                return null;
+            }
+
+            @Override
             public Void visit(InstanceReceiver receiver) {
                 visitor.visit(receiver);
                 return null;
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 c2380c7..2fd444d 100644
--- a/src/main/java/org/zwobble/couscous/ast/structure/NodeStructure.java
+++ b/src/main/java/org/zwobble/couscous/ast/structure/NodeStructure.java
@@ -80,6 +80,11 @@ public class NodeStructure {
             }
 
             @Override
+            public Stream<? extends Node> visit(CastNode cast) {
+                return Stream.of(cast.getExpression());
+            }
+
+            @Override
             public Stream<? extends Node> visit(InstanceReceiver receiver) {
                 return Stream.of(receiver.getExpression());
             }
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 6eab8d4..c296a30 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeMapper.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeMapper.java
@@ -12,4 +12,5 @@ public interface ExpressionNodeMapper<T> {
     T visit(ConstructorCallNode call);
     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 fe3b4a2..fb8da13 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(ConstructorCallNode call);
     T visit(FieldAccessNode fieldAccess);
     T visit(TypeCoercionNode typeCoercion);
+    T visit(CastNode cast);
 
     T visit(InstanceReceiver receiver);
     T visit(StaticReceiver receiver);
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 388acb1..178442d 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(CastNode cast) {
+        return defaultValue;
+    }
+
+    @Override
     public T visit(InstanceReceiver receiver) {
         return defaultValue;
     }
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 189a0cd..bf6240b 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(ConstructorCallNode call);
     void visit(FieldAccessNode fieldAccess);
     void visit(TypeCoercionNode typeCoercion);
+    void visit(CastNode cast);
 
     void visit(InstanceReceiver receiver);
     void visit(StaticReceiver receiver);
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 414d04b..c97e950 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
@@ -302,6 +302,11 @@ public class PythonCodeGenerator {
                 return value;
             }
         }
+
+        @Override
+        public PythonExpressionNode visit(CastNode cast) {
+            throw new UnsupportedOperationException();
+        }
     }
 
     private static PythonExpressionNode generateReceiver(Receiver receiver) {
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 114e4ef..86a3868 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/JavaExpressionReader.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/JavaExpressionReader.java
@@ -10,6 +10,7 @@ import java.util.List;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
+import static org.zwobble.couscous.ast.CastNode.cast;
 import static org.zwobble.couscous.ast.ConstructorCallNode.constructorCall;
 import static org.zwobble.couscous.ast.LiteralNode.literal;
 import static org.zwobble.couscous.ast.MethodCallNode.staticMethodCall;
@@ -102,6 +103,9 @@ public class JavaExpressionReader {
             case ASTNode.ASSIGNMENT:
                 return readAssignment((Assignment)expression);
 
+            case ASTNode.CAST_EXPRESSION:
+                return readCastExpression((CastExpression)expression);
+
             default:
                 throw new RuntimeException("Unsupported expression: " + expression.getClass());
 
@@ -307,6 +311,10 @@ public class JavaExpressionReader {
             operator.isBoolean() ? BooleanValue.REF : left.getType());
     }
 
+    private ExpressionNode readCastExpression(CastExpression expression) {
+        return cast(readExpressionWithoutBoxing(expression.getExpression()), typeOf(expression));
+    }
+
     private ExpressionNode readUnboxedExpression(Expression expression) {
         return readExpression(
             unboxedType(typeOf(expression)),
diff --git a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
index e319353..d90b78b 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
@@ -123,6 +123,11 @@ public class Evaluator implements ExpressionNodeMapper<InterpreterValue> {
         }
     }
 
+    @Override
+    public InterpreterValue visit(CastNode cast) {
+        throw new UnsupportedOperationException();
+    }
+
     private static boolean isIntegerBox(TypeCoercionNode typeCoercion) {
         return typeCoercion.getExpression().getType().equals(IntegerValue.REF) &&
             !typeCoercion.getType().equals(IntegerValue.REF);