Sorting an array together with other array in jq - arrays

Question

I have two arrays in a structure but between elements of arrays has logical connections. (Eg. comments[1] belongs to records[1], comments[2] belongs to records[2])
These arrays are sorted by alpabetical order of records array.
When I want to add a new element for both array then I have sort both arrays. For records array it is easy, but the elements of comments array have to move same way as each element of record.
Input:
{
"records":
[
{"content":"a"},
{"content":"z"}
],
"comments":[
{"content":"something"},
{"content":"anything"}
]
}
New elements are added to the end of arrays:
{
"records":[
{"content":"a"},
{"content":"z"},
{"content":"b"}
],
"comments":[
{"content":"something"},
{"content":"anything"},
{"content":"new element"}
]
}
Expected sorted output:
```json
{
"records":[
{"content":"a"},
{"content":"b"},
{"content":"z"}
],
"comments":[
{"content":"something"},
{"content":"new element"},
{"content":"anything"}
]
}
I tried "to_elements, map, transpose and addfunctions without any (partial) result.

Answer 1

Rather than appending the new elements to the arrays, you could use bsearch to find the insertion point, and then use that to perform the two insertions. Specifically, if $x is not in a sorted array, then the insertion point of $x in the array is -1 - bsearch($x).
You might find this helper function useful:
def insert($x;$i): .[:$i]+[$x]+.[$i:];
Solution
Here then is a solution for the problem at hand:
# It is assumed that (.|f) is a sorted array
def insert_into_sorted($x; f; $y; g):
def insert($x;$i): .[:$i]+[$x]+.[$i:];
(f|bsearch($x)) as $ix
| (if $ix > -1 then $ix else -1 - $ix end) as $i
| f|=insert($x; $i)
| g|=insert($y; $i) ;
insert_into_sorted( {"content": "b"}; .records;
{"content": "new element"}; .comments)