added lox test files

lox.t/inheritance/constructor.lox

@@ -0,0 +1,14 @@
+class A {
+  init(param) {
+    this.field = param;
+  }
+
+  test() {
+    print this.field;
+  }
+}
+
+class B < A {}
+
+var b = B("value");
+b.test(); // expect: value

lox.t/inheritance/inherit_from_function.lox

@@ -0,0 +1,3 @@
+fun foo() {}
+
+class Subclass < foo {} // expect runtime error: Superclass must be a class.

lox.t/inheritance/inherit_from_nil.lox

@@ -0,0 +1,2 @@
+var Nil = nil;
+class Foo < Nil {} // expect runtime error: Superclass must be a class.

lox.t/inheritance/inherit_from_number.lox

@@ -0,0 +1,2 @@
+var Number = 123;
+class Foo < Number {} // expect runtime error: Superclass must be a class.

lox.t/inheritance/inherit_methods.lox

@@ -0,0 +1,14 @@
+class Foo {
+  methodOnFoo() { print "foo"; }
+  override() { print "foo"; }
+}
+
+class Bar < Foo {
+  methodOnBar() { print "bar"; }
+  override() { print "bar"; }
+}
+
+var bar = Bar();
+bar.methodOnFoo(); // expect: foo
+bar.methodOnBar(); // expect: bar
+bar.override(); // expect: bar

lox.t/inheritance/parenthesized_superclass.lox

@@ -0,0 +1,4 @@
+class Foo {}
+
+// [line 4] Error at '(': Expect superclass name.
+class Bar < (Foo) {}

lox.t/inheritance/set_fields_from_base_class.lox

@@ -0,0 +1,38 @@
+class Foo {
+  foo(a, b) {
+    this.field1 = a;
+    this.field2 = b;
+  }
+
+  fooPrint() {
+    print this.field1;
+    print this.field2;
+  }
+}
+
+class Bar < Foo {
+  bar(a, b) {
+    this.field1 = a;
+    this.field2 = b;
+  }
+
+  barPrint() {
+    print this.field1;
+    print this.field2;
+  }
+}
+
+var bar = Bar();
+bar.foo("foo 1", "foo 2");
+bar.fooPrint();
+// expect: foo 1
+// expect: foo 2
+
+bar.bar("bar 1", "bar 2");
+bar.barPrint();
+// expect: bar 1
+// expect: bar 2
+
+bar.fooPrint();
+// expect: bar 1
+// expect: bar 2