Add basic migrations, query expression resolver

redis_developer/orm/query_iterator.py

@@ -0,0 +1,55 @@
+from redis_developer.orm.model import Expression
+
+
+class QueryIterator:
+    """
+    A lazy iterator that yields results from a RediSearch query.
+
+    Examples:
+
+        results = Model.filter(email == "a@example.com")
+
+        # Consume all results.
+        for r in results:
+            print(r)
+
+        # Consume an item at an index.
+        print(results[100])
+
+        # Consume a slice.
+        print(results[0:100])
+
+        # Alternative notation to consume all items.
+        print(results[0:-1])
+
+        # Specify the batch size:
+        results = Model.filter(email == "a@example.com", batch_size=1000)
+        ...
+    """
+    def __init__(self, client, query, batch_size=100):
+        self.client = client
+        self.query = query
+        self.batch_size = batch_size
+
+    def __iter__(self):
+        pass
+
+    def __getattr__(self, item):
+        """Support getting a single value or a slice."""
+
+    # TODO: Query mixin?
+
+    def filter(self, *expressions: Expression):
+        pass
+
+    def exclude(self, *expressions: Expression):
+        pass
+
+    def and_(self, *expressions: Expression):
+        pass
+
+    def or_(self, *expressions: Expression):
+        pass
+
+    def not_(self, *expressions: Expression):
+        pass