Variables do not seem to be tracked across turns

[george1459]

Hey everyone. I am new to Nemo and am using it to build a restaurant booking bot. My rails.co file looks like this (using nemoguardrails==0.9.0). I based it on #246

define user express greeting
  "hello"
  "hi"

define bot express greeting
  "Hello there!"
  "Hi!"

define user request book restaurant
  "I want to book a restaurant"

define bot request which restaurant
  "Which restaurant would you like to book?"

define bot request what time
  "What time would you like to book?"

define bot request what date
  "Which date would you like to book?"

define bot request how many ppl
  "How many people are you booking for?"

define bot express confirm
  "Ok. Confirming you are booking $restaurant on $date at $time for $num_ppl, is that correct?"

define flow book_restaurant
  user request book restaurant

  # Extract the desired restaurant from the user's request as a string literal. If not specified, set as `None`.
  $restaurant = ...

  # Extract the desired date from the user's request as a string literal. If not specified, set as `None`.
  $date = ...

  # Extract the desired time of the day from the user's request as a string literal. If not specified, set as `None`.
  $time = ...

  # Extract the desired number of people from the user's request as an integer. If not specified, set as `None`.
  $num_ppl = ...

  while not $restaurant:
    bot request which restaurant

    user provide which restaurant

    # Extract the desired restaurant from the user's request as a string literal. If not specified, set as `None`.
    $restaurant = ...

  while not $date:
    bot request what date

    user provide what date

    # Extract the desired date from the user's request as a string literal. If not specified, set as `None`.
    $date = ...

  while not $time:
    bot request what time

    user provide what time

    # Extract the desired time of the day from the user's request as a string literal. If not specified, set as `None`.
    $time = ...

  while not $num_ppl:
    bot request how many ppl

    user provide how many ppl

    # Extract the desired number of people from the user's request as an integer. If not specified, set as `None`.
    $num_ppl = ...

  bot express confirm

With this and using GPT-4-turbo, I often seem to encounter problems with variables, in particular how it does not persist across different turns. For instance here is a conversation:

> I want to book Nemo's on Jun 2nd for 2 ppl

By inspecting using the --verbose flag, I see here that:
...
$restaurant =
"Nemo's"
...

What time would you like to book?
> at 7 pm

Which restaurant would you like to book?

I can’t grasp why it would ask this question again, since restaurant has just been filled in. And then if I respond with > Nemo's again, it seems to go into an infinite loop. It appears that the variables are not kept across turns. Could someone point out what I am doing wrong? Thanks!