Is it possible to use JSONLogic as a query language?

Is it possible to use JSONLogic as a query language to filter JSON? Something like this:

var data =
[
	{
		"id": 1,
		"name": "Oliver",
		"email": "[e-mail]"
	},
	{
		"id": 2,
		"name": "Jack",
		"email": "[e-mail]"
	},
	{
		"id": 3,
		"name": "Harry",
		"email": "[e-mail]"
	},
	{
		"id": 4,
		"name": "Jacob",
		"email": "[e-mail]"
	},
	{
		"id": 5,
		"name": "Charlie",
		"email": "[e-mail]"
	},
	{
		"id": 6,
		"name": "Thomas",
		"email": "[e-mail]"
	},
	{
		"id": 7,
		"name": "George",
		"email": "[e-mail]"
	},
	{
		"id": 8,
		"name": "Oscar",
		"email": "[e-mail]"
	},
	{
		"id": 9,
		"name": "James",
		"email": "[e-mail]"
	},
	{
		"id": 10,
		"name": "William",
		"email": "[e-mail]"
	}
]

var filter =
{"or": [
	{"and": [
		{">=": [
			{"var": "id"}, 3
		]},
		{"<=": [
			{"var": "id"}, 5
		]}
	]},
	{">": [
		{"var": "id"}, 7
	]}
]};

jsonLogic.filter(filter, data);

It should return:

[
	{
		"id": 3,
		"name": "Harry",
		"email": "[e-mail]"
	},
	{
		"id": 4,
		"name": "Jacob",
		"email": "[e-mail]"
	},
	{
		"id": 5,
		"name": "Charlie",
		"email": "[e-mail]"
	},
	{
		"id": 8,
		"name": "Oscar",
		"email": "[e-mail]"
	},
	{
		"id": 9,
		"name": "James",
		"email": "[e-mail]"
	},
	{
		"id": 10,
		"name": "William",
		"email": "[e-mail]"
	}
]

[jwadhams]

You could do this by combining JavaScript’s filter with that rule:

data.filter(function(item){
  return jsonLogic.apply(filter, item);
})

You could also monkey-patch this onto the library quickly like:

jsonLogic.filter = function(rule, data){
    if(typeof data.filter !== "function"){
        throw "jsonLogic.filter requires data be an Array";
    }
    return data.filter(function(item){
        return jsonLogic.apply(rule, item);
    });
};

By the way, there’s a special three-argument syntax for < and <= that can simplify your rule:

{ "or": [
    { "<=": [ 3, { "var": "id" }, 5 ] },
    { ">": [ { "var": "id" }, 7 ] }
] };

I hesitate to bake this into the spec, just because I don’t have time right now to write appropriate unit tests for it.

Does this get you where you need to go?

[jwadhams]

I think you’re right, you could pretty quickly patch in replace and add and remove operations with add_operation that act directly on the data object.

I’m not familiar with JsonPointer, but I have used dotty–I just suggested a way to mooch functionality off that library into JsonLogic rules in this issue.

Re: cleaner syntax without var, in your example how does the parser understand that “temp” and “pie.filling” are data names, but “apple” is a literal string? It’s totally doable in a command like {"remove":"/foo"} where that argument can’t be anything but a variable reference, but I don’t think it’ll work everywhere.