Sort a yaml file by the top level node while excluding certain lines from the sorting

[thleo]

Please describe your feature request.
I have a file with one top level parent that I want to remain at the top of the document, and then I have many other parents that I want to sort on a child key. I want to be able to sort only those subsequent parent nodes and leave the specific parent in whatever place in the file it exists in.

Note:

• how to questions should be posted in the discussion board and not raised as an issue.
• V3 will no longer have any enhancements.

Describe the solution you'd like
If we have data1.yml like:

cantrip: Australia
  - animal: kangaroos
  - animal: bears
  - animal: aardvark
awsFunctionminimor:
 - name: minimor
awsFunctionfabulous:
 - name: fabulous
awsFunctiondancingpear:
 - name: dancingpear

And we run a command:

yq '. |= sort_by(.) && ignorelines=[(1,4)]' data1.yml

it could output

cantrip: Australia
  - animal: kangaroos
  - animal: bears
  - animal: aardvark
awsFunctiondancingpear:
 - name: dancingpear
awsFunctionfabulous:
 - name: fabulous
 awsFunctionminimor:
 - name: minimor

Describe alternatives you've considered
I've tried running yq '. |= sort_by(.)' data1.yml which doesn't work as the node is not an array.

Additional context
Add any other context or screenshots about the feature request here.

[mikefarah]

TLDR:

yq 'sort_keys(.) | pick( (["cantrip"] + keys) | unique)' examples/data1.yaml

Explanation:

• First we sort the all keys of the map.
• You want 'cantrip' to go first, we can use pick to specify the map order. Pick takes an array of keys, and will pick those keys in the specified order.
• ["cantrip"] + keys will have the order you want, but "cantrip" will be duplicated, as its also in keys
• we pipe that array through unique, which will drop duplicates while maintaining order