|Object||Concept & Example|
|The Null Object||
Concept: The empty object, called NULL_OB, typically indiactes an error condition.
Example: Erroneous SMILES input.
Concept: Error messages are contained in a sequence of string objects.
Example: SMILES errors, all errors, your messages, and the invalid String.
Concept: Graph-based characterization is used to determine similarity between structures.
Concept: Two-way process communication is an efficient conversation.
Example: Connection, Conversation, and Application.
Concept: Web service is as easy as getting requests and putting responses.
Example: Web Service and Ping.
(available in v4.91)
Concept: Data is converted to and from Daylight Languages and Thor DataTrees.
Example: Terminal and Feeder modes.
Next Section: Advanced Programming Exercises