Function promote

purl.js:69–75

(parent, key)

    }

    function promote(parent, key) {
        if (parent[key].length === 0) return parent[key] = {};
        var t = {};
        for (var i in parent[key]) t[i] = parent[key][i];
        parent[key] = t;
        return t;
    }

    function parse(parts, parent, key, val) {
        var part = parts.shift();