Create parameterised types with correct interpreter type

7 files changed, 93 insertions, 18 deletions

diff --git a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
index 8c3d355..64f28ad 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
@@ -6,13 +6,17 @@ import org.zwobble.couscous.ast.visitors.ExpressionNodeMapper;
 import org.zwobble.couscous.interpreter.errors.ConditionMustBeBoolean;
 import org.zwobble.couscous.interpreter.errors.InvalidCast;
 import org.zwobble.couscous.interpreter.values.*;
+import org.zwobble.couscous.types.ParameterizedType;
 import org.zwobble.couscous.types.ScalarType;
+import org.zwobble.couscous.types.Type;
 import org.zwobble.couscous.types.Types;
 
 import java.util.List;
+import java.util.Optional;
 import java.util.stream.Collectors;
 
 import static org.zwobble.couscous.types.Types.erasure;
+import static org.zwobble.couscous.util.Casts.tryCast;
 import static org.zwobble.couscous.util.ExtraLists.eagerMap;
 
 public class Evaluator implements ExpressionNodeMapper<InterpreterValue> {
@@ -105,7 +109,9 @@ public class Evaluator implements ExpressionNodeMapper<InterpreterValue> {
     public InterpreterValue visit(ConstructorCallNode call) {
         StaticReceiverValue clazz = environment.findClass(erasure(call.getType()));
         List<InterpreterValue> arguments = evalArguments(call.getArguments());
-        return clazz.callConstructor(environment, arguments);
+        Optional<List<Type>> typeParameters = tryCast(ParameterizedType.class, call.getType())
+            .map(type -> type.getParameters());
+        return clazz.callConstructor(environment, typeParameters, arguments);
     }
 
     @Override
diff --git a/src/main/java/org/zwobble/couscous/interpreter/types/InterpreterType.java b/src/main/java/org/zwobble/couscous/interpreter/types/InterpreterType.java
index 8c5bdb9..7ffe5d5 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/types/InterpreterType.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/types/InterpreterType.java
@@ -16,7 +16,7 @@ public interface InterpreterType {
     Set<Type> getSuperTypes();
     Optional<FieldDeclarationNode> getField(String fieldName);
     List<StatementNode> getStaticConstructor();
-    InterpreterValue callConstructor(Environment environment, List<InterpreterValue> arguments);
+    void callConstructor(Environment environment, InterpreterValue thisValue, List<InterpreterValue> arguments);
     InterpreterValue callMethod(Environment environment, InterpreterValue value, MethodSignature signature, List<InterpreterValue> arguments);
     InterpreterValue callStaticMethod(Environment environment, MethodSignature signature, List<InterpreterValue> arguments);
 }
diff --git a/src/main/java/org/zwobble/couscous/interpreter/types/IntrinsicInterpreterType.java b/src/main/java/org/zwobble/couscous/interpreter/types/IntrinsicInterpreterType.java
index 190908b..29b4fe1 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/types/IntrinsicInterpreterType.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/types/IntrinsicInterpreterType.java
@@ -156,10 +156,8 @@ public class IntrinsicInterpreterType implements InterpreterType {
     }
 
     @Override
-    public InterpreterValue callConstructor(Environment environment, List<InterpreterValue> arguments) {
-        ObjectInterpreterValue object = new ObjectInterpreterValue(this);
-        constructor.apply(environment, MethodCallArguments.of(object, new PositionalArguments(arguments)));
-        return object;
+    public void callConstructor(Environment environment, InterpreterValue thisValue, List<InterpreterValue> arguments) {
+        constructor.apply(environment, MethodCallArguments.of(thisValue, new PositionalArguments(arguments)));
     }
 
     @Override
diff --git a/src/main/java/org/zwobble/couscous/interpreter/types/ParameterizedInterpreterType.java b/src/main/java/org/zwobble/couscous/interpreter/types/ParameterizedInterpreterType.java
new file mode 100644
index 0000000..f890fb1
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/interpreter/types/ParameterizedInterpreterType.java
@@ -0,0 +1,65 @@
+package org.zwobble.couscous.interpreter.types;
+
+import org.zwobble.couscous.ast.FieldDeclarationNode;
+import org.zwobble.couscous.ast.MethodSignature;
+import org.zwobble.couscous.ast.StatementNode;
+import org.zwobble.couscous.interpreter.Environment;
+import org.zwobble.couscous.interpreter.values.InterpreterValue;
+import org.zwobble.couscous.types.ScalarType;
+import org.zwobble.couscous.types.Type;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+
+import static org.zwobble.couscous.types.ParameterizedType.parameterizedType;
+
+public class ParameterizedInterpreterType implements InterpreterType {
+    private final InterpreterType rawType;
+    private final List<Type> parameters;
+
+    public ParameterizedInterpreterType(InterpreterType rawType, List<Type> parameters) {
+        this.rawType = rawType;
+        this.parameters = parameters;
+    }
+
+    @Override
+    public Type getType() {
+        return parameterizedType((ScalarType) rawType.getType(), parameters);
+    }
+
+    // TODO: implement the other methods properly.
+    // Possibly worth splitting off a separate notion of interpreter type.
+    // For instance, callConstructor is arguably not relevant here.
+    // (Or that we should be instantiating this type before the call to callConstructor)
+
+    @Override
+    public Set<Type> getSuperTypes() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public Optional<FieldDeclarationNode> getField(String fieldName) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public List<StatementNode> getStaticConstructor() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void callConstructor(Environment environment, InterpreterValue thisValue, List<InterpreterValue> arguments) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public InterpreterValue callMethod(Environment environment, InterpreterValue value, MethodSignature signature, List<InterpreterValue> arguments) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public InterpreterValue callStaticMethod(Environment environment, MethodSignature signature, List<InterpreterValue> arguments) {
+        throw new UnsupportedOperationException();
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/interpreter/types/UserDefinedInterpreterType.java b/src/main/java/org/zwobble/couscous/interpreter/types/UserDefinedInterpreterType.java
index cc072bf..d702720 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/types/UserDefinedInterpreterType.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/types/UserDefinedInterpreterType.java
@@ -1,8 +1,6 @@
 package org.zwobble.couscous.interpreter.types;
 
 import org.zwobble.couscous.ast.*;
-import org.zwobble.couscous.types.ScalarType;
-import org.zwobble.couscous.types.Type;
 import org.zwobble.couscous.interpreter.Environment;
 import org.zwobble.couscous.interpreter.Executor;
 import org.zwobble.couscous.interpreter.InterpreterTypes;
@@ -10,9 +8,13 @@ import org.zwobble.couscous.interpreter.PositionalArguments;
 import org.zwobble.couscous.interpreter.errors.NoSuchMethod;
 import org.zwobble.couscous.interpreter.errors.WrongNumberOfArguments;
 import org.zwobble.couscous.interpreter.values.InterpreterValue;
-import org.zwobble.couscous.interpreter.values.ObjectInterpreterValue;
+import org.zwobble.couscous.types.ScalarType;
+import org.zwobble.couscous.types.Type;
 
-import java.util.*;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
 
 import static com.google.common.collect.Iterables.filter;
 import static org.zwobble.couscous.util.Casts.tryCast;
@@ -59,7 +61,7 @@ public class UserDefinedInterpreterType implements InterpreterType {
     }
 
     @Override
-    public InterpreterValue callConstructor(Environment environment, List<InterpreterValue> arguments) {
+    public void callConstructor(Environment environment, InterpreterValue thisValue, List<InterpreterValue> arguments) {
         ConstructorNode constructor = tryCast(ClassNode.class, type)
             // TODO: add test for this case
             .orElseThrow(() -> new RuntimeException("Cannot instantiate non-class types"))
@@ -68,13 +70,11 @@ public class UserDefinedInterpreterType implements InterpreterType {
             constructor.getArguments(),
             FormalArgumentNode::getType);
         checkMethodArguments(formalArgumentTypes, arguments);
-        InterpreterValue object = new ObjectInterpreterValue(this);
         Executor.callConstructor(
             environment,
             constructor,
-            object,
+            thisValue,
             new PositionalArguments(arguments));
-        return object;
     }
 
     private static void checkMethodArguments(final List<Type> argumentTypes, List<InterpreterValue> arguments) {
diff --git a/src/main/java/org/zwobble/couscous/interpreter/values/StaticReceiverValue.java b/src/main/java/org/zwobble/couscous/interpreter/values/StaticReceiverValue.java
index cf2c9b7..deca938 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/values/StaticReceiverValue.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/values/StaticReceiverValue.java
@@ -4,8 +4,11 @@ import org.zwobble.couscous.ast.MethodSignature;
 import org.zwobble.couscous.interpreter.Environment;
 import org.zwobble.couscous.interpreter.Executor;
 import org.zwobble.couscous.interpreter.types.InterpreterType;
+import org.zwobble.couscous.interpreter.types.ParameterizedInterpreterType;
+import org.zwobble.couscous.types.Type;
 
 import java.util.List;
+import java.util.Optional;
 
 public class StaticReceiverValue implements ReceiverValue {
     private final InterpreterType type;
@@ -35,7 +38,12 @@ public class StaticReceiverValue implements ReceiverValue {
         Executor.exec(environment, type.getStaticConstructor());
     }
 
-    public InterpreterValue callConstructor(Environment environment, List<InterpreterValue> arguments) {
-        return type.callConstructor(environment, arguments);
+    public InterpreterValue callConstructor(Environment environment, Optional<List<Type>> typeParameters, List<InterpreterValue> arguments) {
+        InterpreterType objectType = typeParameters
+            .<InterpreterType>map(parameters -> new ParameterizedInterpreterType(type, parameters))
+            .orElse(type);
+        ObjectInterpreterValue value = new ObjectInterpreterValue(objectType);
+        type.callConstructor(environment, value, arguments);
+        return value;
     }
 }
diff --git a/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java b/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
index 9fe84e6..e6316b5 100644
--- a/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
@@ -2,7 +2,6 @@ package org.zwobble.couscous.tests.interpreter;
 
 import com.google.common.collect.ImmutableMap;
 import org.hamcrest.Matcher;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.zwobble.couscous.ast.*;
 import org.zwobble.couscous.interpreter.*;
@@ -250,7 +249,6 @@ public class EvaluatorTests extends BackendEvalTests {
     }
 
     @Test
-    @Ignore("WIP")
     public void typeOfValueCanBeParameterisedType() {
         ScalarType rawType = ScalarType.of("Box");
         ClassNode classNode = ClassNode.builder(rawType)