doc: added notes about things to be decided soon

Author: ntamas

doc/NOTES.md

@@ -0,0 +1,17 @@
+# Open questions
+
+- Shall we allow string representations of enums to be resolved to their
+  corresponding enum values? This would make it possible to write something
+  like `"directed"` instead of `Adjacency.DIRECTED`.
+
+- Shall we allow the user to refer to vertices by strings and resolve strings
+  automatically to vertex names, or do we want to force the user to indicate
+  explicitly when he wants to do a by-name lookup?
+
+- Shall we allow the user to refer to individual edges by a `(source, target)`
+  tuple if it is unambiguous?
+
+- Shall we allow the user to specify edge weight vectors simply by writing the
+  name of the edge attribute storing the weights?
+
+- Shall we treat the `weight` edge attribute implicitly as edge weights?