实现类似 goMongoDB 的查询表达式对象评估 [英] Implementing goMongoDB-like Query expression object evaluation

问题描述

我一直在寻找一个 MongoDb-like ( 稍微修改的示例 ui 加载器(使用 ?profile= 调用)FILE_TO_PROFILE)

<头><风格>正文{边距:0px}</风格><身体><div class="forp"></div><?phpregister_shutdown_function(功能() {//下一个代码可以在开发模式下附加到 PHP 脚本中?><script src="../forp-ui/js/forp.min.js"></script><脚本>(功能(f){f.find(".forp").每个(功能(el){el.css('margin:50px;height:300px;border:1pxsolid #333');}).forp({堆栈:<?php echo json_encode(forp_dump());?>,//模式:固定"})})(forp);<?php});//开始forpforp_start();//我们要分析的 PHP 脚本包括($_GET['个人资料'])；//停止 forpforp_end();?>

解决方案

最新更新

<块引用>

@baba 给出了一个很好的原始 PHP 版本的类实现了类似 MongoDB 的查询表达式对象评估，但是输出结构有点不同，我的意思是嵌套数组输出中的点符号([release.arch] =>x86 )，而不是常规数组( [release] => Array([arch] => x86) ).我很感激您的提示，如何按此顺序使该类与 mongoDB 完全兼容，因为它似乎与原始 PHP 类实现严格相关.

========================================================================

答案:

你想要的很简单，你只需要在当前代码输入和输出循环中2个更正，你就会得到你的新格式.

我是什么意思?

A. 已更改

 foreach ( $array as $part ) {$this->flatten[] = $this->convert($part);}

到

 foreach ( $array as $k => $part ) {$this->flatten[$k] = $this->convert($part);}

B.改变了

 foreach ( $this->flatten as $data ) {$this->check($find, $data, $type) 和 $f[] = $data;}

致:

 foreach ( $this->flatten as $k => $data ) {$this->check($find, $data, $type) 和 $f[] = $this->array[$k];}

用于休息的新阵列

$json = '[{"name": "蒙戈",发布": {"arch": "x86",版本":22，年份":2012},类型":数据库"},{"name": "蒙戈",发布": {"arch": "x64",版本":21，年份":2012},类型":数据库"},{"name": "蒙戈",发布": {"arch": "x86",版本":23，年份":2013},类型":数据库"},{"name": "MongoBuster",发布": {拱":["x86",x64"],版本":23，年份":2013},类型":数据库"},{孩子们": {舞蹈": [一"，二"，{三": {一个苹果"，"b": 700000,c":8.8}}],"lang": "php","tech": "json",年份":2013},"key": "不同",价值":酷"}]';$array = json_decode($json, true);

简单测试

$s = new ArrayStandard($array);print_r($s->find(array("release.arch"=>"x86")));

输出

数组([0] =>大批([名称] =>蒙戈[类型] =>D b[发布] =>大批([拱] =>x86[版本] =>22[年] =>2012年))[1] =>大批([名称] =>蒙戈[类型] =>D b[发布] =>大批([拱] =>x86[版本] =>23[年] =>2013年)))

如果你还想保留原来的array key position你可以有

 foreach ( $this->flatten as $k => $data ) {$this->check($find, $data, $type) 和 $f[$k] = $this->array[$k];}

只是为了好玩部分

A. 支持 regex

只是为了好玩，我用别名 $preg 或 $match 添加了对 $regex 的支持，这意味着你可以拥有

print_r($s->find(array("release.arch" => array('$regex' => "/4$/"))));

或

print_r($s->find(array("release.arch" => array('$regex' => "/4$/"))));

输出

数组([1] =>大批([名称] =>蒙戈[类型] =>D b[发布] =>大批([拱] =>x64[版本] =>21[年] =>2012年)))

B. 使用像 queries

这样的简单数组

$queryArray = array(发布" =>大批(拱" =>x86"));$d = $s->find($s->convert($queryArray));

$s->convert($queryArray) 已转换

数组([发布] =>大批([拱] =>x86))

到

数组([release.arch] =>x86)

C. 模数 $mod

print_r($s->find(array(release.version" =>大批('$mod' =>大批(23 =>0)))));//检查 release.version % 23 == 0 ;

D. 使用 $size

计算元素

print_r($s->find(array(release.arch" =>大批('$size' =>2))));//返回 count(release.arch) == 2;

E. 检查它是否匹配数组 $all

中的所有元素

print_r($s->find(array(release.arch" =>大批('$all' =>大批("x86",x64")))));

输出

数组([3] =>大批([名称] =>蒙哥巴斯特[发布] =>大批([拱] =>大批([0] =>x86[1] =>x64)[版本] =>23[年] =>2013年)[类型] =>D b))

F. 如果您不确定元素键名，那么您可以使用 $has 它就像 的 opposite$in

print_r($s->find(array(发布" =>大批('$has' =>x86"))));

========================================================================

旧更新

<块引用>

@Baba 提供了一个优秀的类，它是使用 SPL 编写的.我想知道如何在没有 SPL 的情况下重写此代码.原因是多次调用这个类会产生函数开销，可以避免在原始 PHP 中重写它，并且可能在最终版本中使用 goto 语句，以避免递归函数调用.

========================================================================

因为你不想要 SPL 和函数......花了一段时间但我能够想出一个灵活且易于使用的替代类

为避免多次加载数组，您只需声明一次:

$array = json_decode($json, true);$s = new ArrayStandard($array);

A. 找出 release.year 是 2013

$d = $s->find(array(release.year" =>2013"));打印_r($d);

输出

数组([0] =>大批([名称] =>蒙戈[类型] =>D b[release.arch] =>x86[release.version] =>23[发布.年份] =>2013年))

B. 第一次，您可以运行复杂的 $and 或 $or 语句，例如 find where release.arch = x86 和 release.year = 2012

$d = $s->find(array(release.arch" =>"x86",release.year" =>2012"), ArrayStandard::COMPLEX_AND);打印_r($d);

输出

数组([0] =>大批([名称] =>蒙戈[类型] =>D b[release.arch] =>x86[release.version] =>22[发布.年份] =>2012年))

C. 想象一个更复杂的查询

$d = $s->find(array(release.year" =>大批('$in' =>大批("2012",2013")),release.version" =>大批('$gt' =>22),release.arch" =>大批('$func' =>函数 ($a) {返回 $a == "x86";})), ArrayStandard::COMPLEX_AND);打印_r($d);

输出

数组([0] =>大批([名称] =>蒙戈[类型] =>D b[release.arch] =>x86[release.version] =>23[发布.年份] =>2013年))

新的修改类

class ArrayStandard {const COMPLEX_OR = 1;const COMPLEX_AND = 2;私人 $array;私人$代币；私人 $found;函数 __construct(array $array) {$this->array = $array;foreach ( $array as $k => $item ) {$this->tokens[$k] = $this->tokenize($item);}}公共函数 getTokens() {返回 $this->tokens;}公共函数转换($part){返回 $this->tokenize($part, null, false);}公共函数查找(数组 $find，$type = 1){$f = 数组();foreach ( $this->tokens as $k => $data ) {$this->check($find, $data, $type) 和 $f[$k] = $this->array[$k];}返回 $f;}私有函数检查($find，$data，$type){$o = $r = 0;//义务 &要求foreach ( $data as $key => $value ) {如果(isset($find[$key])){$r++;$options = $find[$key];如果(is_array($options)){重置($选项)；$eK = key($options);$eValue = current($options);如果 (strpos($eK, '$') === 0) {$this->evaluate($eK, $value, $eValue) 和 $o ++;} 别的 {throw new InvalidArgumentException('Expession key 中缺少$"');}} 别的 {$this->evaluate('$eq', $value, $options) 和 $o ++;}}}如果($o === 0)返回假；if ($type == self::COMPLEX_AND 和 $o !== $r)返回假；返回真；}私有函数 getValue(array $path) {返回计数($路径)>1 ?$this->getValue(array_slice($path, 1), $this->array[$path[0]]) : $this->array[$path[0]];}私有函数标记化($array, $prefix = '', $addParent = true) {$paths = array();$px = 空($prefix)?空: $prefix .".";foreach ( $array as $key => $items ) {如果(is_array($items)){$addParent &&$paths[$px .$key] = json_encode($items);foreach ( $this->tokenize($items, $px . $key) as $k => $path ) {$paths[$k] = $path;}} 别的 {$paths[$px .$key] = $items;}}返回 $paths;}私有函数评估($func，$a，$b){$r = 假；开关($func){案例$eq":$r = $a == $b;休息;案例$not":$r = $a != $b;休息;案例$gte":案例$gt":如果 ($this->checkType($a, $b)) {$r = $a >$b;}休息;案例$lte":案例$lt":如果 ($this->checkType($a, $b)) {$r = $a <$b;}休息;案例$in":如果 (!is_array($b))throw new InvalidArgumentException('$in 选项的无效参数必须是数组');$r = in_array($a, $b);休息;案例$has":如果 (is_array($b))throw new InvalidArgumentException('不支持 $has 数组的无效参数');$a = @json_decode($a, true) ?: 大批();$r = in_array($b, $a);休息;案例$all":$a = @json_decode($a, true) ?: 大批();如果 (!is_array($b))throw new InvalidArgumentException('$all 选项的无效参数必须是数组');$r = count(array_intersect_key($a, $b)) == count($b);休息;案例$regex":案例$preg":案例$match":$r = (boolean) preg_match($b, $a, $match);休息;案例$size":$a = @json_decode($a, true) ?: 大批();$r = (int) $b == count($a);休息;案例$mod":如果 (!is_array($b))throw new InvalidArgumentException('$mod 选项的无效参数必须是数组');列表($x，$y)=每个($b)；$r = $a % $x == 0;休息;案例$func":案例$fn":案例$f":如果 (!is_callable($b))throw new InvalidArgumentException('函数应该是可调用的');$r = $b($a);休息;默认 :throw new ErrorException("Condition not valid ... Use $fn for custom operation");休息;}返回 $r;}私有函数 checkType($a, $b) {如果 (is_numeric($a) && is_numeric($b)) {$a = filter_var($a, FILTER_SANITIZE_NUMBER_FLOAT);$b = filter_var($b, FILTER_SANITIZE_NUMBER_FLOAT);}如果 (gettype($a) != gettype($b)) {返回假；}返回真；}}

I've been looking for a MongoDb-like ( http://docs.mongodb.org/manual/applications/read/#find, docs.mongodb.org/manual/reference/operators/ ) query expression object evaluation function implementation or a class. It may cover not all the advanced features, and should have extensible architecture.

MongoDB-like query expression objects are easy for understanding and usage, providing ability to write clean, self-explaining code, because both query and objects to search in, are associative arrays.

Basically talking its a convenient function to extract information from php arrays. Knowing the array structure(the arrayPath), it will allow to perform operations on multidimensional arrays data, without the need for multiple nested loops.

If you are not familiar with MongoDb, take a look at a given expression object and array to search in.

I wrote it as JSON string for simplicity. The object contents makes no sense, just showng the MongoDb query syntax.

MongoDb-like query expression object

{
    "name": "Mongo",
    "type": "db",
    "arch": {
        "$in": [
            "x86",
            "x64"
        ]
    },
    "version": {
        "$gte": 22
    },
    "released": {
        "$or": {
            "$lt": 2013,
            "$gt": 2012
        }
    }
}

The array to search in

[
    {
        "name": "Mongo",
        "type": "db",
        "release": {
            "arch": "x86",
            "version": 22,
            "year": 2012
        }
    },
    {
        "name": "Mongo",
        "type": "db",
        "release": {
            "arch": "x64",
            "version": 21,
            "year": 2012
        }
    },
    {
        "name": "Mongo",
        "type": "db",
        "release": {
            "arch": "x86",
            "version": 23,
            "year": 2013
        }
    }
]

Find using Mongo-like query expressions

So, with the help of the function, we should be able to issue the following query to the target array.

$found=findLikeMongo($array, $queryExpr); //resulting in a $array[0] value;
//@return found array

Get array path using Mongo-like query expressions

$arrayPath=getPathFromMongo($array, $queryExpr);// resulting in array("0")
//@return array path, represented as an array where entries are consecutive keys.

Homework

• I found that goessner.net/articles/JsonPath/ could possibly cover my needs(not being an exact match because it uses Xpath-like expressions), the caveat is, that it heavily relies on regular expressions and string parsing, what will definitely slow it down compared to array only(JSON like) implementation.

• Also I've found a similar question here, @stackoverflow Evaluating MongoDB-like JSON Queries in PHP. The resulting answer was to use some SPL functions, which I am used to avoid most of the time.
  Wonder if the author had came up with function, he had been trying to develop.

• The possible arrayPath implementation was found on thereisamoduleforthat.com/content/dealing-deep-arrays-php, thus the lack of this implementation, is that it relies on pointers.

I know its not a trivial question with a oneliner answer, that's why I'm asking it before starting the actual development of my own class.

I appreciate architecture tips, related or similar code, which may be a good practice example for building php "if..else" expressions on the fly.emphasized text

How to write a non-SPL version?

@Baba provided an excellent class, which is written with the use of SPL. I wonder how to rewrite this code without SPL.

There are two reasons for this

• calling the class multiple times will give function overhead, that can be avoided rewriting it in raw PHP.
• it would be easily portable to raw Javascript where SPL is not available, leading to easier code maintenance on both platforms.

Results

The created ArrayQuery class is published on Github, consider checking-out the repository for updates.

SPL, raw PHP version and Chequer2 FORP profiler output

In brief-

1. the raw PHP version performs 10x faster than the SPL one, consuming 20% less memory.
2. Chequer2 class performs 40% slower than PHP SPL class, and almost 20x slower than raw PHP version.
3. MongoDb is the fastest(10x faster than raw PHP implementation and consumes 5x less memory), do not use these classes unless you are sure you want to avoid interaction with MongoDb.

MongoDb version

SPL version

Raw PHP(latest ArrayQuery class) version

Chequer2 version

MongoDb reference test profiling code

$m = new MongoClient(); // connect
$db = $m->testmongo; // select a database
$collection = $db->data;
$loops=100;
for ($i=0; $i<$loops; $i++) {
    $d = $collection->find(array("release.year" => 2013));
}
print_r( iterator_to_array($d) );

PHP with SPL class profiling code

include('data.php');
include('phpmongo-spl.php');
$s = new ArrayCollection($array, array("release.year" => 2013),false);
$loops=100;
for ($i=0; $i<$loops; $i++) {
    $d = $s->parse();
}
print_r( $d );

The SPL class parse() function has been slightly modified to return the value after execution, it could be also be modified to accept expression, but it's not essential for profiling purposes as the expression is being reevaluated every time.

raw PHP(latest ArrayQuery class) profiling code

include('data.php');
include('phpmongo-raw.php');
$s = new ArrayStandard($array);
$loops=100;
for ($i=0; $i<$loops; $i++) {
    $d = $s->find(array("release.year" => 2013));
}
print_r( $d );

chequer2 PHP profiling code

<?php
include('data.php');
include('../chequer2/Chequer.php');
$query=array("release.year" => 2013);

$loops=100;
for ($i=0; $i<$loops; $i++) {
    $result=Chequer::shorthand('(.release.year > 2012) ? (.) : NULL')
        ->walk($array);

}
print_r($result);
?>

data used(same as @baba provided in his answer)

$json = '[{
    "name":"Mongo",
    "type":"db",
    "release":{
        "arch":"x86",
        "version":22,
        "year":2012
    }
},
{
    "name":"Mongo",
    "type":"db",
    "release":{
        "arch":"x64",
        "version":21,
        "year":2012
    }
},
{
    "name":"Mongo",
    "type":"db",
    "release":{
        "arch":"x86",
        "version":23,
        "year":2013
    }
},      
{
    "key":"Diffrent",
    "value":"cool",
    "children":{
        "tech":"json",
        "lang":"php",
        "year":2013
    }
}
]';

$array = json_decode($json, true);

the forp-ui slightly modified sample ui loader(to be called with ?profile=FILE_TO_PROFILE)

<!doctype html>
<html>
    <head>
        <style>
            body {margin : 0px}
        </style>
    </head>
    <body>
        <div class="forp"></div>
<?php
register_shutdown_function(
    function() {
        // next code can be append to PHP scripts in dev mode
        ?>
        <script src="../forp-ui/js/forp.min.js"></script>
        <script>
        (function(f) {
            f.find(".forp")
             .each(
                function(el) {
                    el.css('margin:50px;height:300px;border:1px solid #333');
                }
             )
             .forp({
                stack : <?php echo json_encode(forp_dump()); ?>,
                //mode : "fixed"
             })
        })(forp);
        </script>
        <?php
    }
);

// start forp
forp_start();

// our PHP script to profile
include($_GET['profile']);

// stop forp
forp_end();
?>
</body>
</html>

解决方案

Latest Update

@baba has given a great raw PHP version of a class implementing MongoDB-like query expression object evaluation, but the output structure differs a bit, I mean the dot notation in the nested array output( [release.arch] => x86 ), instead of regular arrays( [release] => Array([arch] => x86) ). I would appreciate your tip how to make the class fully compatible with mongoDB in this order, as it seems its strictly tied to the raw PHP class implementation.

=======================================================================

Answer:

What you want is very easy, All you need is 2 corrections in the current code input and output loop and you would get your new format.

What do i mean ?

A. Changed

  foreach ( $array as $part ) {
        $this->flatten[] = $this->convert($part);
    }

To

    foreach ( $array as $k => $part ) {
        $this->flatten[$k] = $this->convert($part);
    }

B. Changed

    foreach ( $this->flatten as $data ) {
        $this->check($find, $data, $type) and $f[] = $data;
    }

To:

    foreach ( $this->flatten as $k => $data ) {
        $this->check($find, $data, $type) and $f[] = $this->array[$k];
    }

New Array for resting 

$json = '[
  {
    "name": "Mongo",
    "release": {
      "arch": "x86",
      "version": 22,
      "year": 2012
    },
    "type": "db"
  },
  {
    "name": "Mongo",
    "release": {
      "arch": "x64",
      "version": 21,
      "year": 2012
    },
    "type": "db"
  },
  {
    "name": "Mongo",
    "release": {
      "arch": "x86",
      "version": 23,
      "year": 2013
    },
    "type": "db"
  },
  {
    "name": "MongoBuster",
    "release": {
      "arch": [
        "x86",
        "x64"
      ],
      "version": 23,
      "year": 2013
    },
    "type": "db"
  },
  {
    "children": {
      "dance": [
        "one",
        "two",
        {
          "three": {
            "a": "apple",
            "b": 700000,
            "c": 8.8
          }
        }
      ],
      "lang": "php",
      "tech": "json",
      "year": 2013
    },
    "key": "Diffrent",
    "value": "cool"
  }
]';

$array = json_decode($json, true);

Simple Test

$s = new ArrayStandard($array);
print_r($s->find(array("release.arch"=>"x86")));

Output

Array
(
    [0] => Array
        (
            [name] => Mongo
            [type] => db
            [release] => Array
                (
                    [arch] => x86
                    [version] => 22
                    [year] => 2012
                )

        )

    [1] => Array
        (
            [name] => Mongo
            [type] => db
            [release] => Array
                (
                    [arch] => x86
                    [version] => 23
                    [year] => 2013
                )

        )

)

If you also want to retain original array key position you can have

    foreach ( $this->flatten as $k => $data ) {
        $this->check($find, $data, $type) and $f[$k] = $this->array[$k];
    }

Just for Fun Part

A. Support for regex

Just for fun i added support for $regex with alias $preg or $match which means you can have

print_r($s->find(array("release.arch" => array('$regex' => "/4$/"))));

Or

print_r($s->find(array("release.arch" => array('$regex' => "/4$/"))));

Output

Array
(
    [1] => Array
        (
            [name] => Mongo
            [type] => db
            [release] => Array
                (
                    [arch] => x64
                    [version] => 21
                    [year] => 2012
                )

        )

)

B. Use Simple array like queries

$queryArray = array(
        "release" => array(
                "arch" => "x86"
        )
);
$d = $s->find($s->convert($queryArray));

$s->convert($queryArray) has converted

Array
(
    [release] => Array
        (
            [arch] => x86
        )

)

To

Array
(
    [release.arch] => x86
)

C. Modulus $mod

print_r($s->find(array(
        "release.version" => array(
                '$mod' => array(
                        23 => 0
                )
        )
)));

 //Checks release.version % 23 == 0 ;

D. Count elements with $size

print_r($s->find(array(
        "release.arch" => array(
                '$size' => 2
        )
)));

// returns count(release.arch) == 2;

E. Check if it matches all element in array $all

print_r($s->find(array(
        "release.arch" => array(
                '$all' => array(
                        "x86",
                        "x64"
                )
        )
)));

Output

Array
(
    [3] => Array
        (
            [name] => MongoBuster
            [release] => Array
                (
                    [arch] => Array
                        (
                            [0] => x86
                            [1] => x64
                        )

                    [version] => 23
                    [year] => 2013
                )

            [type] => db
        )

)

F. If you are not sure of the element key name then you ca use $has its like the opposite of $in

print_r($s->find(array(
        "release" => array(
                '$has' => "x86"
        )
)));

=======================================================================

Old Update

@Baba provided an excellent class, which is written with the use of SPL. I wonder how to rewrite this code without SPL. The reason is that calling this class multiple times will give function overhead, that can be avoided rewriting it in raw PHP, and maybe using goto statement in final version, to avoid recursive function calls.

=======================================================================

Since you don't want SPL and functions .. it took a while but i was able to come up with alternative class that is also flexible and easy to use

To avoid loading the array multiple times you declare it once :

$array = json_decode($json, true);
$s = new ArrayStandard($array);

A. Find where release.year is 2013

$d = $s->find(array(
        "release.year" => "2013"
));
print_r($d);

Output

Array
(
    [0] => Array
        (
            [name] => Mongo
            [type] => db
            [release.arch] => x86
            [release.version] => 23
            [release.year] => 2013
        )

)

B. For the first time you can run complex $and or $or statement like find where release.arch = x86 and release.year = 2012

$d = $s->find(array(
        "release.arch" => "x86",
        "release.year" => "2012"
), ArrayStandard::COMPLEX_AND);

print_r($d);

Output

Array
(
    [0] => Array
        (
            [name] => Mongo
            [type] => db
            [release.arch] => x86
            [release.version] => 22
            [release.year] => 2012
        )

)

C. Imagine a much more complex query

$d = $s->find(array(
        "release.year" => array(
                '$in' => array(
                        "2012",
                        "2013"
                )
        ),
        "release.version" => array(
                '$gt' => 22
        ),
        "release.arch" => array(
                '$func' => function ($a) {
                    return $a == "x86";
                }
        )
), ArrayStandard::COMPLEX_AND);

print_r($d);

Output

Array
(
    [0] => Array
        (
            [name] => Mongo
            [type] => db
            [release.arch] => x86
            [release.version] => 23
            [release.year] => 2013
        )

)

The new Modified class

class ArrayStandard {
    const COMPLEX_OR = 1;
    const COMPLEX_AND = 2;
    private $array;
    private $tokens;
    private $found;

    function __construct(array $array) {
        $this->array = $array;
        foreach ( $array as $k => $item ) {
            $this->tokens[$k] = $this->tokenize($item);
        }   
    }

    public function getTokens() {
        return $this->tokens;
    }

    public function convert($part) {
        return $this->tokenize($part, null, false);
    }

    public function find(array $find, $type = 1) {
        $f = array();
        foreach ( $this->tokens as $k => $data ) {
            $this->check($find, $data, $type) and $f[$k] = $this->array[$k];
        }
        return $f;
    }

    private function check($find, $data, $type) {
        $o = $r = 0; // Obigation & Requirement
        foreach ( $data as $key => $value ) {
            if (isset($find[$key])) {
                $r ++;
                $options = $find[$key];
                if (is_array($options)) {
                    reset($options);
                    $eK = key($options);
                    $eValue = current($options);
                    if (strpos($eK, '$') === 0) {
                        $this->evaluate($eK, $value, $eValue) and $o ++;
                    } else {
                        throw new InvalidArgumentException('Missing "$" in expession key');
                    }
                } else {
                    $this->evaluate('$eq', $value, $options) and $o ++;
                }
            }
        }

        if ($o === 0)
            return false;

        if ($type == self::COMPLEX_AND and $o !== $r)
            return false;

        return true;
    }

    private function getValue(array $path) {
        return count($path) > 1 ? $this->getValue(array_slice($path, 1), $this->array[$path[0]]) : $this->array[$path[0]];
    }

    private function tokenize($array, $prefix = '', $addParent = true) {
        $paths = array();
        $px = empty($prefix) ? null : $prefix . ".";
        foreach ( $array as $key => $items ) {
            if (is_array($items)) {
                $addParent && $paths[$px . $key] = json_encode($items);
                foreach ( $this->tokenize($items, $px . $key) as $k => $path ) {
                    $paths[$k] = $path;
                }
            } else {
                $paths[$px . $key] = $items;
            }
        }
        return $paths;
    }

    private function evaluate($func, $a, $b) {
        $r = false;

        switch ($func) {
            case '$eq' :
                $r = $a == $b;
                break;
            case '$not' :
                $r = $a != $b;
                break;
            case '$gte' :
            case '$gt' :
                if ($this->checkType($a, $b)) {
                    $r = $a > $b;
                }
                break;

            case '$lte' :
            case '$lt' :
                if ($this->checkType($a, $b)) {
                    $r = $a < $b;
                }
                break;
            case '$in' :
                if (! is_array($b))
                    throw new InvalidArgumentException('Invalid argument for $in option must be array');
                $r = in_array($a, $b);
                break;

            case '$has' :
                if (is_array($b))
                    throw new InvalidArgumentException('Invalid argument for $has array not supported');
                $a = @json_decode($a, true) ?  : array();
                $r = in_array($b, $a);
                break;

            case '$all' :
                $a = @json_decode($a, true) ?  : array();
                if (! is_array($b))
                    throw new InvalidArgumentException('Invalid argument for $all option must be array');
                $r = count(array_intersect_key($a, $b)) == count($b);
                break;

            case '$regex' :
            case '$preg' :
            case '$match' :

                $r = (boolean) preg_match($b, $a, $match);
                break;

            case '$size' :
                $a = @json_decode($a, true) ?  : array();
                $r = (int) $b == count($a);
                break;

            case '$mod' :
                if (! is_array($b))
                    throw new InvalidArgumentException('Invalid argument for $mod option must be array');
                list($x, $y) = each($b);
                $r = $a % $x == 0;
                break;

            case '$func' :
            case '$fn' :
            case '$f' :
                if (! is_callable($b))
                    throw new InvalidArgumentException('Function should be callable');
                $r = $b($a);
                break;

            default :
                throw new ErrorException("Condition not valid ... Use $fn for custom operations");
                break;
        }

        return $r;
    }

    private function checkType($a, $b) {
        if (is_numeric($a) && is_numeric($b)) {
            $a = filter_var($a, FILTER_SANITIZE_NUMBER_FLOAT);
            $b = filter_var($b, FILTER_SANITIZE_NUMBER_FLOAT);
        }

        if (gettype($a) != gettype($b)) {
            return false;
        }
        return true;
    }
}

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