Dialog Rails

This section explains how to create dialog rails using Colang.

Definition

Dialog Rails are a type of rail enforcing the path that the dialog between the user and the bot should take. Typically, they involve three components:

1. The definition of user messages, which includes the canonical forms, e.g., user expressed greeting, and potential utterances.
2. The definition of bot messages, which includes the canonical forms, e.g., bot express greeting, and potential utterances.
3. The definition of flows “connecting” user messages and the bot messages.

The example below extends the Hello World example by creating the user expressed greeting and bot express greeting messages.

examples/v2_x/tutorial/hello_world_2/main.co

import core
flow main
  user expressed greeting
  bot express greeting
flow user expressed greeting
  user said "hi" or user said "hello"
flow bot express greeting
  bot say "Hello world!"

LLM Integration

While the example above has more structure, it is still rigid in the sense that it only works with the exact inputs “hi” and “hello”.

To enable the use of the LLM to drive the interaction for inputs that are not matched exactly by flows, you have to activate the llm continuation flow, which is part of the llm module in the Colang Standard Library (CSL).

examples/v2_x/tutorial/hello_world_3/main.co

import core
import llm
flow main
  activate llm continuation
  activate greeting
flow greeting
  user expressed greeting
  bot express greeting
flow user expressed greeting
  user said "hi" or user said "hello"
flow bot express greeting
  bot say "Hello world!"

Flow activation is a core mechanism in Colang 2.0. In the above example, the greeting dialog rail is also encapsulated as a flow which is activated in the main flow. If a flow is not activated (or called explicitly by another flow), it will not be used.

Testing

$ nemoguardrails chat --config=examples/v2_x/tutorial/hello_world_3
> hello there!
Hello world!
> how are you?
I am an AI, so I don't have feelings like humans do. But thank you for asking! Is there something specific you would like to know or talk about?

First, you can see how the user utterance “hello there!” is matched to the flow user expressed greeting based on its similarity to the expected user answers. Secondly, any unexpected user utterance like “how are you?” will trigger the LLM to generate a suitable response. This is all automatically handled and taken care of by the flow llm continuation. To have more explicit control over the interaction loop checkout the Interaction Loop example.

$ nemoguardrails chat --config=examples/v2_x/tutorial/hello_world_3 --verbose

The next example will show you how to describe multimodal rails using Colang.