Union of literals

[p-christ]

Is this the only way to specify that something that can be 3 different literals?

union([literal('system'), literal('user'), literal('assistant')])

i'd quite like to do it like this instead, is it possible?

literal('system', 'user', 'assistant')

[xcfox]

You might be looking for picklist:

picklist(['system', 'user', 'assistant'])