Implement static constructor and fields in interpreter

10 files changed, 144 insertions, 64 deletions

diff --git a/src/main/java/org/zwobble/couscous/interpreter/Environment.java b/src/main/java/org/zwobble/couscous/interpreter/Environment.java
index e57f8e5..daee3ed 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Environment.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Environment.java
@@ -1,24 +1,29 @@
 package org.zwobble.couscous.interpreter;
 
-import java.util.Map;
-import java.util.Optional;
 import org.zwobble.couscous.ast.TypeName;
 import org.zwobble.couscous.ast.VariableDeclaration;
 import org.zwobble.couscous.ast.VariableNode;
 import org.zwobble.couscous.ast.identifiers.Identifier;
 import org.zwobble.couscous.interpreter.errors.UnboundVariable;
 import org.zwobble.couscous.interpreter.errors.VariableNotInScope;
-import org.zwobble.couscous.interpreter.values.ConcreteType;
 import org.zwobble.couscous.interpreter.values.InterpreterValue;
+import org.zwobble.couscous.interpreter.values.StaticReceiverValue;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+
 import static java.util.stream.Collectors.toMap;
 
 public class Environment {
-    private final Project project;
+    private final Map<TypeName, StaticReceiverValue> types;
     private final Optional<InterpreterValue> thisValue;
     private final Map<Identifier, VariableEntry> stackFrame;
-    
+    private final Project project;
+
     public Environment(Project project, Optional<InterpreterValue> thisValue, Map<VariableDeclaration, Optional<InterpreterValue>> stackFrame) {
         this.project = project;
+        this.types = new HashMap<>();
         this.thisValue = thisValue;
         this.stackFrame = stackFrame.entrySet().stream()
             .collect(toMap(
@@ -46,8 +51,13 @@ public class Environment {
         put(variable.getDeclaration().getId(), value);
     }
     
-    public ConcreteType findClass(TypeName className) {
-        return project.findClass(className);
+    public StaticReceiverValue findClass(TypeName className) {
+        if (!types.containsKey(className)) {
+            StaticReceiverValue value = new StaticReceiverValue(project.findClass(className));
+            types.put(className, value);
+            value.callStaticConstructor(this);
+        }
+        return types.get(className);
     }
     
     public Environment withStackFrame(Optional<InterpreterValue> thisValue, Map<VariableDeclaration, Optional<InterpreterValue>> stackFrame) {
diff --git a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
index 6c40960..1d88c6b 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
@@ -55,8 +55,7 @@ public class Evaluator implements ExpressionNodeMapper<InterpreterValue> {
         assignment.getTarget().accept(new AssignableExpressionNodeVisitor(){
             @Override
             public void visit(FieldAccessNode fieldAccess) {
-                // TODO: handle static receiver
-                InterpreterValue left = eval(((InstanceReceiver)fieldAccess.getLeft()).getExpression());
+                ReceiverValue left = evalReceiver(fieldAccess.getLeft());
                 left.setField(fieldAccess.getFieldName(), value);
             }
             
@@ -91,24 +90,10 @@ public class Evaluator implements ExpressionNodeMapper<InterpreterValue> {
         return evalReceiver(methodCall.getReceiver())
             .callMethod(environment, signature, arguments);
     }
-
-    private ReceiverValue evalReceiver(Receiver receiver) {
-        return receiver.accept(new Receiver.Mapper<ReceiverValue>() {
-            @Override
-            public ReceiverValue visit(ExpressionNode receiver) {
-                return new InstanceReceiverValue(eval(receiver));
-            }
-
-            @Override
-            public ReceiverValue visit(TypeName receiver) {
-                return new StaticReceiverValue(environment.findClass(receiver));
-            }
-        });
-    }
     
     @Override
     public InterpreterValue visit(ConstructorCallNode call) {
-        ConcreteType clazz = environment.findClass(call.getType());
+        StaticReceiverValue clazz = environment.findClass(call.getType());
         List<InterpreterValue> arguments = evalArguments(call.getArguments());
         return clazz.callConstructor(environment, arguments);
     }
@@ -120,8 +105,7 @@ public class Evaluator implements ExpressionNodeMapper<InterpreterValue> {
 
     @Override
     public InterpreterValue visit(FieldAccessNode fieldAccess) {
-        // TODO: handle static receiver
-        InterpreterValue left = eval(((InstanceReceiver)fieldAccess.getLeft()).getExpression());
+        ReceiverValue left = evalReceiver(fieldAccess.getLeft());
         return left.getField(fieldAccess.getFieldName());
     }
 
@@ -173,4 +157,18 @@ public class Evaluator implements ExpressionNodeMapper<InterpreterValue> {
             .map(argument -> eval(argument))
             .collect(Collectors.toList());
     }
+
+    private ReceiverValue evalReceiver(Receiver receiver) {
+        return receiver.accept(new Receiver.Mapper<ReceiverValue>() {
+            @Override
+            public ReceiverValue visit(ExpressionNode receiver) {
+                return new InstanceReceiverValue(eval(receiver));
+            }
+
+            @Override
+            public ReceiverValue visit(TypeName receiver) {
+                return environment.findClass(receiver);
+            }
+        });
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/org/zwobble/couscous/interpreter/Executor.java b/src/main/java/org/zwobble/couscous/interpreter/Executor.java
index 6de4828..60f7d9c 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Executor.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Executor.java
@@ -16,14 +16,9 @@ import static org.zwobble.couscous.interpreter.Evaluator.evalCondition;
 
 public class Executor implements StatementNodeMapper<Optional<InterpreterValue>> {
     public static InterpreterValue callMethod(Environment environment, CallableNode method, Optional<InterpreterValue> thisValue, PositionalArguments arguments) {
-        final org.zwobble.couscous.interpreter.Environment innerEnvironment = buildEnvironment(environment, method, thisValue, arguments);
-        for (final org.zwobble.couscous.ast.StatementNode statement : method.getBody()) {
-            final java.util.Optional<org.zwobble.couscous.interpreter.values.InterpreterValue> result = exec(innerEnvironment, statement);
-            if (result.isPresent()) {
-                return result.get();
-            }
-        }
-        return UnitInterpreterValue.UNIT;
+        Environment innerEnvironment = buildEnvironment(environment, method, thisValue, arguments);
+        return exec(innerEnvironment, method.getBody())
+            .orElse(UnitInterpreterValue.UNIT);
     }
 
     private static Environment buildEnvironment(final Environment environment, final CallableNode method, Optional<InterpreterValue> thisValue, PositionalArguments arguments) {
@@ -46,6 +41,16 @@ public class Executor implements StatementNodeMapper<Optional<InterpreterValue>>
             }));
     }
 
+    public static Optional<InterpreterValue> exec(Environment environment, Iterable<StatementNode> statements) {
+        for (StatementNode statement : statements) {
+            Optional<InterpreterValue> result = exec(environment, statement);
+            if (result.isPresent()) {
+                return result;
+            }
+        }
+        return Optional.empty();
+    }
+
     public static Optional<InterpreterValue> exec(Environment environment, StatementNode statement) {
         return statement.accept(new Executor(environment));
     }
diff --git a/src/main/java/org/zwobble/couscous/interpreter/Interpreter.java b/src/main/java/org/zwobble/couscous/interpreter/Interpreter.java
index 5493e52..8ec461a 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Interpreter.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Interpreter.java
@@ -3,8 +3,8 @@ package org.zwobble.couscous.interpreter;
 import com.google.common.collect.ImmutableMap;
 import org.zwobble.couscous.ast.MethodSignature;
 import org.zwobble.couscous.ast.TypeName;
-import org.zwobble.couscous.interpreter.values.ConcreteType;
 import org.zwobble.couscous.interpreter.values.InterpreterValue;
+import org.zwobble.couscous.interpreter.values.StaticReceiverValue;
 
 import java.util.List;
 import java.util.Optional;
@@ -24,11 +24,11 @@ public class Interpreter {
             Optional.empty(),
             ImmutableMap.of());
         
-        ConcreteType clazz = environment.findClass(className);
+        StaticReceiverValue clazz = environment.findClass(className);
         MethodSignature signature = new MethodSignature(
             methodName,
             eagerMap(arguments, argument -> argument.getType().getName()),
             returnType);
-        return clazz.callStaticMethod(environment, signature, arguments);
+        return clazz.callMethod(environment, signature, arguments);
     }
 }
\ No newline at end of file
diff --git a/src/main/java/org/zwobble/couscous/interpreter/values/ConcreteType.java b/src/main/java/org/zwobble/couscous/interpreter/values/ConcreteType.java
index 41c0445..3a4443f 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/values/ConcreteType.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/values/ConcreteType.java
@@ -1,10 +1,7 @@
 package org.zwobble.couscous.interpreter.values;
 
 import com.google.common.collect.ImmutableMap;
-import org.zwobble.couscous.ast.ClassNode;
-import org.zwobble.couscous.ast.FormalArgumentNode;
-import org.zwobble.couscous.ast.MethodSignature;
-import org.zwobble.couscous.ast.TypeName;
+import org.zwobble.couscous.ast.*;
 import org.zwobble.couscous.interpreter.*;
 import org.zwobble.couscous.interpreter.errors.NoSuchMethod;
 import org.zwobble.couscous.interpreter.errors.WrongNumberOfArguments;
@@ -18,7 +15,6 @@ import static java.util.stream.Collectors.toMap;
 import static org.zwobble.couscous.util.ExtraLists.list;
 
 public class ConcreteType {
-    
     public static <T> ConcreteType.Builder<T> builder(Class<T> interpreterValueType, TypeName reference) {
         return new Builder<>(interpreterValueType, reference);
     }
@@ -30,7 +26,7 @@ public class ConcreteType {
     public static ConcreteType.Builder<ObjectInterpreterValue> classBuilder(String name) {
         return builder(ObjectInterpreterValue.class, name);
     }
-    
+
     public static class Builder<T> {
         private final ImmutableMap.Builder<String, FieldValue> fields = ImmutableMap.builder();
         private MethodValue constructor = new MethodValue(list(), (environment, arguments) -> InterpreterValues.UNIT);
@@ -88,6 +84,7 @@ public class ConcreteType {
                 name,
                 Collections.emptySet(),
                 fields.build(),
+                list(),
                 constructor,
                 methods.build(),
                 staticMethods.build());
@@ -115,7 +112,14 @@ public class ConcreteType {
                     return Executor.callMethod(environment, method, Optional.empty(), arguments);
                 });
             }));
-        return new ConcreteType(classNode.getName(), classNode.getSuperTypes(), fields, constructor, methods, staticMethods);
+        return new ConcreteType(
+            classNode.getName(),
+            classNode.getSuperTypes(),
+            fields,
+            classNode.getStaticConstructor(),
+            constructor,
+            methods,
+            staticMethods);
     }
 
     private static List<TypeName> getArgumentTypes(List<FormalArgumentNode> arguments) {
@@ -124,6 +128,7 @@ public class ConcreteType {
     private final TypeName name;
     private final Set<TypeName> superTypes;
     private final Map<String, FieldValue> fields;
+    private final List<StatementNode> staticConstructor;
     private final MethodValue constructor;
     private final Map<MethodSignature, MethodValue> methods;
     private final Map<MethodSignature, StaticMethodValue> staticMethods;
@@ -132,13 +137,14 @@ public class ConcreteType {
         TypeName name,
         Set<TypeName> superTypes,
         Map<String, FieldValue> fields,
-        MethodValue constructor,
+        List<StatementNode> staticConstructor, MethodValue constructor,
         Map<MethodSignature, MethodValue> methods,
         Map<MethodSignature, StaticMethodValue> staticMethods)
     {
         this.name = name;
         this.superTypes = superTypes;
         this.fields = fields;
+        this.staticConstructor = staticConstructor;
         this.constructor = constructor;
         this.methods = methods;
         this.staticMethods = staticMethods;
@@ -155,7 +161,11 @@ public class ConcreteType {
     public Optional<FieldValue> getField(String fieldName) {
         return Optional.ofNullable(fields.get(fieldName));
     }
-    
+
+    public List<StatementNode> getStaticConstructor() {
+        return staticConstructor;
+    }
+
     public InterpreterValue callMethod(Environment environment, InterpreterValue receiver, MethodSignature signature, List<InterpreterValue> arguments) {
         MethodValue method = findMethod(methods, signature, arguments);
         return method.apply(environment, MethodCallArguments.of(receiver, new PositionalArguments(arguments)));
diff --git a/src/main/java/org/zwobble/couscous/interpreter/values/InstanceReceiverValue.java b/src/main/java/org/zwobble/couscous/interpreter/values/InstanceReceiverValue.java
index 3c3d932..8179394 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/values/InstanceReceiverValue.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/values/InstanceReceiverValue.java
@@ -17,4 +17,14 @@ public class InstanceReceiverValue implements ReceiverValue {
         ConcreteType type = value.getType();
         return type.callMethod(environment, value, signature, arguments);
     }
+
+    @Override
+    public InterpreterValue getField(String fieldName) {
+        return value.getField(fieldName);
+    }
+
+    @Override
+    public void setField(String fieldName, InterpreterValue value) {
+        this.value.setField(fieldName, value);
+    }
 }
diff --git a/src/main/java/org/zwobble/couscous/interpreter/values/InterpreterFields.java b/src/main/java/org/zwobble/couscous/interpreter/values/InterpreterFields.java
new file mode 100644
index 0000000..fc082a5
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/interpreter/values/InterpreterFields.java
@@ -0,0 +1,36 @@
+package org.zwobble.couscous.interpreter.values;
+
+import org.zwobble.couscous.interpreter.InterpreterTypes;
+import org.zwobble.couscous.interpreter.errors.NoSuchField;
+import org.zwobble.couscous.interpreter.errors.UnboundField;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class InterpreterFields {
+    // TODO: distinguish static and non-static fields
+
+    private final ConcreteType type;
+    private final Map<String, InterpreterValue> fields;
+
+    public InterpreterFields(ConcreteType type) {
+        this.type = type;
+        this.fields = new HashMap<>();
+    }
+
+    public InterpreterValue getField(String fieldName) {
+        type.getField(fieldName).orElseThrow(() -> new NoSuchField(fieldName));
+        if (fields.containsKey(fieldName)) {
+            return fields.get(fieldName);
+        } else {
+            throw new UnboundField(fieldName);
+        }
+    }
+
+    public void setField(String fieldName, InterpreterValue value) {
+        FieldValue field = type.getField(fieldName)
+            .orElseThrow(() -> new NoSuchField(fieldName));
+        InterpreterTypes.checkIsInstance(field.getType(), value);
+        fields.put(fieldName, value);
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/interpreter/values/ObjectInterpreterValue.java b/src/main/java/org/zwobble/couscous/interpreter/values/ObjectInterpreterValue.java
index 566ff80..e46ae45 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/values/ObjectInterpreterValue.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/values/ObjectInterpreterValue.java
@@ -1,20 +1,16 @@
 package org.zwobble.couscous.interpreter.values;
 
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Optional;
-import org.zwobble.couscous.interpreter.InterpreterTypes;
-import org.zwobble.couscous.interpreter.errors.NoSuchField;
-import org.zwobble.couscous.interpreter.errors.UnboundField;
 import org.zwobble.couscous.values.PrimitiveValue;
 
+import java.util.Optional;
+
 public class ObjectInterpreterValue implements InterpreterValue {
     private final ConcreteType type;
-    private final Map<String, InterpreterValue> fields;
+    private final InterpreterFields fields;
     
     public ObjectInterpreterValue(ConcreteType type) {
         this.type = type;
-        this.fields = new HashMap<>();
+        this.fields = new InterpreterFields(type);
     }
     
     @Override
@@ -29,19 +25,11 @@ public class ObjectInterpreterValue implements InterpreterValue {
     
     @Override
     public InterpreterValue getField(String fieldName) {
-        type.getField(fieldName).orElseThrow(() -> new NoSuchField(fieldName));
-        if (fields.containsKey(fieldName)) {
-            return fields.get(fieldName);
-        } else {
-            throw new UnboundField(fieldName);
-        }
+        return fields.getField(fieldName);
     }
     
     @Override
     public void setField(String fieldName, InterpreterValue value) {
-        FieldValue field = type.getField(fieldName)
-            .orElseThrow(() -> new NoSuchField(fieldName));
-        InterpreterTypes.checkIsInstance(field.getType(), value);
-        fields.put(fieldName, value);
+        fields.setField(fieldName, value);
     }
 }
\ No newline at end of file
diff --git a/src/main/java/org/zwobble/couscous/interpreter/values/ReceiverValue.java b/src/main/java/org/zwobble/couscous/interpreter/values/ReceiverValue.java
index 5b24f95..5d6d804 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/values/ReceiverValue.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/values/ReceiverValue.java
@@ -7,4 +7,6 @@ import java.util.List;
 
 public interface ReceiverValue {
     InterpreterValue callMethod(Environment environment, MethodSignature signature, List<InterpreterValue> arguments);
+    InterpreterValue getField(String fieldName);
+    void setField(String fieldName, InterpreterValue value);
 }
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 f7ce1f6..9844e33 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/values/StaticReceiverValue.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/values/StaticReceiverValue.java
@@ -2,18 +2,39 @@ package org.zwobble.couscous.interpreter.values;
 
 import org.zwobble.couscous.ast.MethodSignature;
 import org.zwobble.couscous.interpreter.Environment;
+import org.zwobble.couscous.interpreter.Executor;
 
 import java.util.List;
 
 public class StaticReceiverValue implements ReceiverValue {
     private final ConcreteType type;
+    private final InterpreterFields fields;
 
     public StaticReceiverValue(ConcreteType type) {
         this.type = type;
+        this.fields = new InterpreterFields(type);
     }
 
     @Override
     public InterpreterValue callMethod(Environment environment, MethodSignature signature, List<InterpreterValue> arguments) {
         return type.callStaticMethod(environment, signature, arguments);
     }
+
+    @Override
+    public InterpreterValue getField(String fieldName) {
+        return fields.getField(fieldName);
+    }
+
+    @Override
+    public void setField(String fieldName, InterpreterValue value) {
+        fields.setField(fieldName, value);
+    }
+
+    public void callStaticConstructor(Environment environment) {
+        Executor.exec(environment, type.getStaticConstructor());
+    }
+
+    public InterpreterValue callConstructor(Environment environment, List<InterpreterValue> arguments) {
+        return type.callConstructor(environment, arguments);
+    }
 }