Can't put values of LIST_COUNT, LIST_RANGE, etc into a VAR variable

The following syntax is incorrect in both local and global scope:
`VAR my_list_size = 0`
`~ my_list_size = {LIST_COUNT(LIST_ALL(my_list))}`

Errors with:
> Expected value expression to be assigned to temporary variable but saw '{LIST_COUNT(LIST_ALL(list))}'

I am unsure if I'm doing it wrong, if this is a bug, or if this is a missing feature. There are examples in the documentation that don't work though:
`VAR knowledgeState = ()`
Is not valid syntax either.

Running on Linux.