Submit HW1

java-type-checker/java_type_checker/expressions.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 
 from .types import Type
+import re
 
 
 class Expression(object):
@@ -31,6 +32,12 @@ def __init__(self, name, declared_type):
         self.name = name                    #: The name of the variable
         self.declared_type = declared_type  #: The declared type of the variable (Type)
 
+    def static_type(self):
+        return self.declared_type
+
+    def check_types(self):
+        pass
+
 
 class Literal(Expression):
     """ A literal value entered in the code, e.g. `5` in the expression `x + 5`.
@@ -39,11 +46,20 @@ def __init__(self, value, type):
         self.value = value  #: The literal value, as a string
         self.type = type    #: The type of the literal (Type)
 
+    def static_type(self):
+        return self.type
+
+    def check_types(self):
+        pass
+
 
 class NullLiteral(Literal):
     def __init__(self):
         super().__init__("null", Type.null)
 
+    def static_type(self):
+        return Type.null
+
 
 class MethodCall(Expression):
     """
@@ -55,6 +71,37 @@ def __init__(self, receiver, method_name, *args):
         self.method_name = method_name  #: The name of the method to call (String)
         self.args = args                #: The method arguments (list of Expressions)
 
+    def static_type(self):
+        return self.receiver.static_type().method_named(self.method_name).return_type
+
+    def check_types(self):
+        for arg in self.args:
+            arg.check_types()
+
+        # Check not literal type 
+        if not self.receiver.static_type().is_subtype_of(Type.object):
+            raise JavaTypeError("Type {0} does not have methods".format(
+                self.receiver.static_type().name))
+
+        expected_types = self.receiver.static_type().method_named(self.method_name).argument_types
+
+        # Check number of args
+        if len(self.args) != len(expected_types):
+            raise JavaTypeError("Wrong number of arguments for {0}.{1}(): expected {2}, got {3}".format(
+                    self.receiver.static_type().name,
+                    self.method_name,
+                    len(expected_types),
+                    len(self.args)))
+
+        # Check type of args
+        for i in range(len(self.args)):
+            if not self.args[i].static_type().is_subtype_of(expected_types[i]):
+                raise JavaTypeError("{0}.{1}() expects arguments of type {2}, but got {3}".format(
+                        self.receiver.static_type().name,
+                        self.method_name,
+                        names(expected_types),
+                        names([a.static_type() for a in self.args])))
+
 
 class ConstructorCall(Expression):
     """
@@ -64,6 +111,30 @@ def __init__(self, instantiated_type, *args):
         self.instantiated_type = instantiated_type  #: The type to instantiate (Type)
         self.args = args                            #: Constructor arguments (list of Expressions)
 
+    def static_type(self):
+        return self.instantiated_type
+
+    def check_types(self):
+        if not self.instantiated_type.is_subtype_of(Type.object):
+            error = "Type {0} is not instantiable".format(
+                self.instantiated_type.name)
+            raise JavaTypeError(error)
+        try:
+            expected_types = self.instantiated_type.constructor.argument_types
+            if len(self.args) != len(expected_types):
+                raise JavaTypeError("Wrong number of arguments for {0} constructor: expected {1}, got {2}".format(
+                        self.instantiated_type.name,
+                        len(expected_types),
+                        len(self.args)))
+            for i in range(len(self.args)):
+                if not self.args[i].static_type().is_subtype_of(expected_types[i]):
+                    raise JavaTypeError("{0} constructor expects arguments of type {1}, but got {2}".format(
+                            self.instantiated_type.name,
+                            names(expected_types),
+                            names([a.static_type() for a in self.args])))
+        except AttributeError:
+            raise JavaTypeError("Type {0} is not instantiable".format(
+                self.instantiated_type.name))
 
 class JavaTypeError(Exception):
     """ Indicates a compile-time type error in an expression.

java-type-checker/java_type_checker/types.py

@@ -12,7 +12,13 @@ def __init__(self, name, direct_supertypes=[]):
     def is_subtype_of(self, other):
         """ True if this type can be used where the other type is expected.
         """
-        return True  # TODO: implement
+        if other == self or other in self.direct_supertypes:
+            return True
+        else:
+            for st in self.direct_supertypes:
+                if st.is_subtype_of(other):
+                    return True
+        return False
 
     def is_supertype_of(self, other):
         """ Convenience counterpart to is_subtype_of().
@@ -72,6 +78,15 @@ class NullType(Type):
     def __init__(self):
         super().__init__("null")
 
+    def is_supertype_of(self, other):
+        return False
+
+    def is_subtype_of(self, other):
+        return True
+
+    def method_named(self, name):
+        raise NoSuchMethod("Cannot invoke method {0}() on null".format(name))
+
 
 class NoSuchMethod(Exception):
     pass

python-attr-lookup/python-attr-lookup.iml

@@ -20,5 +20,17 @@
         <SOURCES />
       </library>
     </orderEntry>
+    <orderEntry type="module-library" scope="TEST">
+      <library name="JUnit5.0">
+        <CLASSES>
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-api/5.0.0/junit-jupiter-api-5.0.0.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/apiguardian/apiguardian-api/1.0.0/apiguardian-api-1.0.0.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.0.0/opentest4j-1.0.0.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-commons/1.0.0/junit-platform-commons-1.0.0.jar!/" />
+        </CLASSES>
+        <JAVADOC />
+        <SOURCES />
+      </library>
+    </orderEntry>
   </component>
 </module>

python-attr-lookup/src/plang/PythonObject.java

@@ -51,7 +51,13 @@ public List<PythonObject> getMRO() {
      * result (i.e. it remembers the list buildMRO() returned and keeps returning it).
      */
     protected List<PythonObject> buildMRO() {
-        throw new UnsupportedOperationException("not implemented yet");
+//      throw new UnsupportedOperationException("not implemented yet");
+        List<PythonObject> mroBuild = new ArrayList<>();
+        mroBuild.add(this);
+        if (type != null) {
+            mroBuild.addAll(type.getMRO());
+        }
+        return mroBuild;
     }
 
     /**
@@ -62,7 +68,22 @@ protected List<PythonObject> buildMRO() {
      * @throws PythonAttributeException When there is no attribute on this object with that name.
      */
     public final PythonObject get(String attrName) throws PythonAttributeException {
-        throw new UnsupportedOperationException("not implemented yet");
+
+//        for(Utensil utensil : getKitchenUtensils()) {
+//        }
+//
+//        if (attrs.containsKey(attrName)) {
+//            return attrs.get(attrName);
+//        } else if (getMRO().size() >= 2) {
+//            return getMRO().get(1).get(attrName);
+//        }
+
+        for (PythonObject pythonObject : getMRO()) {
+            if (pythonObject.attrs.containsKey(attrName)) {
+                return pythonObject.attrs.get(attrName);
+            }
+        }
+        throw new PythonAttributeException(this, attrName);
     }
 
     /**
@@ -74,7 +95,8 @@ public final PythonObject get(String attrName) throws PythonAttributeException {
      * @param value Its new value
      */
     public final void set(String attrName, PythonObject value) {
-        throw new UnsupportedOperationException("not implemented yet");
+//        throw new UnsupportedOperationException("not implemented yet");
+        attrs.put(attrName, value);
     }
 
     @Override

python-attr-lookup/src/plang/PythonType.java

@@ -41,15 +41,22 @@ public PythonObject getBase() {
 
     @Override
     protected List<PythonObject> buildMRO() {
-        throw new UnsupportedOperationException("not implemented yet");
+        List<PythonObject> mroBuild = new ArrayList<>();
+        mroBuild.add(this);
+        if (base != null) {
+            mroBuild.addAll(base.getMRO());
+        }
+//        mroBuild.addAll(base.getMRO());
+        return mroBuild;
+//        throw new UnsupportedOperationException("not implemented yet");
     }
 
     /**
      * Creates and returns a new instance of this class, i.e. a PythonObject whose type is
      * this PythonType.
      */
     public PythonObject instantiate() {
-        throw new UnsupportedOperationException("not implemented yet");
+        return new PythonObject(this);
     }
 
     @Override