Unflatten a JSON object

Benchmark created by Aadit M Shah on October 6, 2013

Preparation HTML

<script>
var object = {
    "foo[0].bar": true,
    "foo[1].baz": false
};

function controlUnflatten(data) {
    "use strict";
    if (Object(data) !== data || Array.isArray(data))
        return data;
    var result = {}, cur, prop, parts, idx;
    for(var p in data) {
        cur = result, prop = "";
        parts = p.split(".");
        for(var i=0; i<parts.length; i++) {
            idx = !isNaN(parseInt(parts[i]));
            cur = cur[prop] || (cur[prop] = (idx ? [] : {}));
            prop = parts[i];
        }
        cur[prop] = data[p];
    }
    return result[""];
}

function testUnflatten(table) {
    var result = {};

    for (var path in table) {
        var cursor = result, length = path.length, property = "", index = 0;

        while (index < length) {
            var char = path.charAt(index);

            if (char === "[") {
                var start = index + 1,
                    end = path.indexOf("]", start),
                    cursor = cursor[property] = cursor[property] || [],
                    property = path.slice(start, end),
                    index = end + 1;
            } else {
                var cursor = cursor[property] = cursor[property] || {},
                    start = char === "." ? index + 1 : index,
                    bracket = path.indexOf("[", start),
                    dot = path.indexOf(".", start);

                if (bracket < 0 && dot < 0) var end = index = length;
                else if (bracket < 0) var end = index = dot;
                else if (dot < 0) var end = index = bracket;
                else var end = index = bracket < dot ? bracket : dot;

                var property = path.slice(start, end);
            }
        }

        cursor[property] = table[path];
    }

    return result[""];
}
</script>

Test runner

testUnflatten(object);

controlUnflatten(object);

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.

• Revision 1: published by Aadit M Shah on October 6, 2013
• Revision 2: published by Aadit M Shah on October 6, 2013
• Revision 3: published by Robert Koritnik on December 14, 2014