A function to parse object path in JSON.

parseObjectPath.js

/**
 * Parse the property path string.
 *
 * @param {string} path The property path.
 * @returns {string[]} Returns the array of path.
 */
function parseObjectPath(path) {
    var i = 0;
    var l = path.length;
    var ch;

    var T_KEYWORD = 1;
    var T_PROP_SQ = 2; // ['prop_name']
    var T_PROP_DQ = 3; // ["prop_name"]
    var T_PROP_NO = 4; // [1]
    var type = T_KEYWORD;
    var keywords = [];
    var keywordBuffer = [];

    var oneOf = function (ch, str) {
        var j = 0;
        var c = str.charAt(j);

        while (c) {
            if (c === ch) {
                return true;
            } else {
                j += 1;
                c = str.charAt(j);
            }
        }

        return false;
    };

    var whitespace = function () {
        while (i < l && oneOf(path.charAt(i), ' \r\n\t')) {
            ++i;
        }
    };

    var unexpected = function (ch) {
        throw new SyntaxError('unexpected token: ' + ch + ' at pos ' + i);
    };

    var read = function () {
        return path.charAt(i);
    };

    var flushKeyword = function () {
        var k = keywordBuffer.length;
        var c;

        while (k--) {
            c = keywordBuffer[k];
            if (oneOf(c, ' \t\r\n')) {
                keywordBuffer.pop();
            } else {
                break;
            }
        }

        k = keywordBuffer.join('');

        k && keywords.push(k);

        keywordBuffer = [];
    };

    var readNumber = function () {
        var num = [];

        while (true) {
            ch = read();
            if (oneOf(ch, '0123456789')) {
                num.push(ch);
                i += 1;
            } else {
                break;
            }
            if (i >= l) {
                throw new SyntaxError('unexpected end');
            }
        }

        return parseInt(num.join(''), 10);
    };

    var readString = function (qoute) {
        var str = [];

        while (true) {
            ch = read();
            i += 1;
            if (ch === '\\') {
                ch = read();
                if (ch === qoute) {
                    str.push(ch);
                    i += 1;
                } else if (ch === '\\') {
                    str.push(ch);
                    i += 1;
                }
            } else if (ch === qoute) {
                break;
            } else {
                str.push(ch);
            }
            if (i >= l) {
                throw new SyntaxError('unexpected end');
            }
        }

        return str.join('');
    };

    whitespace();

    ch = path.charAt(i);

    if (ch === '.') {
        unexpected(ch);
    }

    while (i < l) {
        if (type === T_KEYWORD) {
            ch = read();
            if (ch === '[') {
                flushKeyword();
                i += 1;
                whitespace();
                ch = read();
                if (ch === "'") {
                    i += 1;
                    type = T_PROP_SQ;
                } else if (ch === '"') {
                    i += 1;
                    type = T_PROP_DQ;
                } else if (ch === ']') {
                    unexpected(']');
                } else {
                    type = T_PROP_NO;
                }
            } else if (ch === '.') {
                flushKeyword();
                i += 1;
                whitespace();
                ch = read();
                if (oneOf(ch, '.[')) {
                    unexpected(ch);
                }
            } else {
                keywordBuffer.push(ch);
                i += 1;
            }
        } else if (type === T_PROP_SQ || type === T_PROP_DQ) {
            keywords.push(readString(type === T_PROP_SQ ? "'" : '"'));
            whitespace();
            ch = read();
            if (ch !== ']') {
                unexpected(ch);
            }
            i += 1;
            type = T_KEYWORD;
        } else if (type === T_PROP_NO) {
            keywords.push(readNumber());
            whitespace();
            ch = read();
            if (ch !== ']') {
                unexpected(ch);
            }
            i += 1;
            type = T_KEYWORD;
        }
    }

    flushKeyword();

    return keywords;
}

// var keywords = parseObjectPath("['the-key-of-the-person-object'].skills[0][123123]");
// console.log(keywords);