Filtering recursive by key?

[kdezz]

I've a situation in which I don't know the keys, for example I have a structure that might look something like this:

{
	"robots": {
		"random_robot_id_39422": {
			"robot_information": 8338
		},
		"random_robot_id_39434": {
			"robot_information": 8113
		},
		"random_robot_id_23823": {
			"robot_information": 8058
		},
		"random_robot_id_97434": {
			"robot_information": 3328
		},
		"random_robot_id_17343": {
			"robot_information": 1001
		}
	}
}

What would be the best way to filter by the ID of the key? For example, if I wanted to retrieve the random_robot_id_17343 node.

[markborkum]

@kdezz, we are actively developing the "callables" capability for exactly this use case (see #14 for details).

For example, using the entries() and match(regexp) functions:

$["robots"][entries()][?(@[0][match("_17343$")])][1]

The above JSONPath tests the key-value pairs of the "robots" JSON object for keys that end with "_17343" and then extracts the corresponding value.

Please note that the match(regexp) function is not yet implemented.

[grandprixgp]

Am I right in thinking that match() should return True/False to satisfy the ? operator?

[markborkum]

@grandprixgp The ? operator is satisfied if a subscript yields a JSON value (i.e., logical disjunction). The match callable yields a JSON array representing the match data (with the same semantics as the MatchData class in the Ruby standard library). For example:

$["string"][?(@[match("pattern")])]

yields all "string"s that match the given "pattern", and

$["string"][match("pattern")][?(@[1][parseInt()] > 42)][2]

yields the second capture group of "pattern" applied to "string" if the first capture group, cast to an integer, satisfies a predicate.

Please note that the parseInt function is not yet implemented.

(Edit: Add closing square bracket to second example.)

[grandprixgp]

Thanks for clarification!