Miller 6 and jsonlines: cut field by name

[aborruso]

Hi,
I have a very stupid question

I have this input

{"name":"andrea","info":{"age":49,"city":"Palermo"}}

If I cat it I have name=andrea,info.age=49,info.city=Palermo.

If I want to cut info.age field, running mlr --ijsonl cut -f 'info.age' i.jsonl I have empty result.
What's the field name I must use?

Thank you

[johnkerl]

Hi @aborruso ! This is more of #310 #763 #948.

There isn't a field called info.age until the final (implicit) flatten (https://miller.readthedocs.io/en/latest/flatten-unflatten/). There's a field called info which is a map which contains a key age. The final (implicit) flatten is to prepare for CSV output.

You can work around this by doing the flatten explicitly:

$ mlr --ijsonl flatten then cut -f 'info.age' i.jsonl
info.age=49

I do intend (#948) to let non-DSL verbs like cut be able to treat things like info.age syntactically -- this needs to be coded up.