Simplified type system

src/types/Is.go

@@ -0,0 +1,21 @@
+package types
+
+// Is returns true if the encountered type `a` can be converted into the expected type `b`.
+func Is(a Type, b Type) bool {
+	if a == nil {
+		return true
+	}
+
+	if a == b {
+		return true
+	}
+
+	aPointer, aIsPointer := a.(*Pointer)
+	bPointer, bIsPointer := b.(*Pointer)
+
+	if aIsPointer && bIsPointer && (bPointer.To == nil || aPointer.To == bPointer.To) {
+		return true
+	}
+
+	return false
+}