Backreferences in jq like sed or vi? - jq

Question

I have the following string in my input to jq:
"\n*blah\n**tim\nbob was here\n*item1\n**item2\n"
And I'm able to match the first \n* with the following:
[match("(\n\\*[A-Za-z0-9]*\n)";"g")]
Which gives me the following matches:
[
{
"offset": 0,
"length": 7,
"string": "\n*blah\n",
"captures": [
{
"offset": 0,
"length": 7,
"string": "\n*blah\n",
"name": null
}
]
},
{
"offset": 25,
"length": 8,
"string": "\n*item1\n",
"captures": [
{
"offset": 25,
"length": 8,
"string": "\n*item1\n",
"name": null
}
]
}
]
My goal however, is to search for these and add an extra \n to the start of the matched \n* lines.
I don't appear to be able to do backreferences using gsub, so is there a similar functionality to what can be done in sed and vi using backreference matches in jq?

Answer 1

Here is a demonstration using a named capture ?<a> with sub and gsub:
$ jq -Mn '
"\n*blah\n**tim\nbob was here\n*item1\n**item2\n"
| sub("(?<a>\n\\*[A-Za-z0-9]*\n)";"\n\(.a)";"g")
, gsub("(?<a>\n\\*[A-Za-z0-9]*\n)";"\n\(.a)")
'
output
"\n\n*blah\n**tim\nbob was here\n\n*item1\n**item2\n"
"\n\n*blah\n**tim\nbob was here\n\n*item1\n**item2\n"