ok I’ve been in contact with chatgpt and gemmini on this and they are really out to lunch a lot of the time.

I am using https://github.com/mikefarah/yq

I am reading from xml and need to ensure single items are arrays, and I have been successful at that with several objects including:

.xdxf.lexicon.ar[].def[].def[].def[0].def[].ex |= ([] + .)

I can check the data with (note the 3rd def[0])

.xdxf.lexicon.ar[].def[].def[].def[0].def[] 
deftext: district
sr:
  kref: "null"
categ: "null"
ex: []
deftext: revue
ex:
  - +@type: exm
    +@author: ""
    +@source: ""
    ex_orig: kɔrɔman
    ex_tran: ancien

that shows both added empty arrays and existing arrays. But the problem is some of the items in ex[] are mandatory, so I want to populate ex[] with +@type: exm to get me started.

I have tried many syntax variations each with //, select and unique. Either the comands hang or are not returning any or bad data. I don’t want to have any ex: [] as below. I want to have at minimum:

ex:
  - +@type: exm

Samples of what i have tried:

.xdxf.lexicon.ar[].def[].def[].def[0].def[].ex = (.xdxf.lexicon.ar[].def[].def[].def[0].def[].ex + [{"+@type": "exm"}] | unique)

.xdxf.lexicon.ar[].def[].def[].def[0].def[].ex // [] | .xdxf.lexicon.ar[].def[].def[].def[0].def[].ex += [{"@type":"exm"}]

.xdxf.lexicon.ar[].def[].def[].def[0].def[].ex // .xdxf.lexicon.ar[].def[].def[].def[0].def[].ex += [{"@type":"exm"}]

.xdxf.lexicon.ar[].def[].def[].def[0].def[] | select(.key == "ex" and . == []) | . |= { ex: [{"@type":"exm"}] }