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Re: Simple expression parser for PHP.

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Daniel Pitts wrote:

> On 12/2/12 3:45 AM, Thomas 'PointedEars' Lahn wrote:
>> Daniel Pitts wrote:
>>> On 12/1/12 9:58 AM, Thomas 'PointedEars' Lahn wrote:
>>>> Daniel Pitts wrote:
>>>>> I have a requirement that I need to take an expression and evaluate
>>>>> it.
>>>>>
>>>>>     I'd very much like to avoid using PHP's eval(), for obvious
>>>>>     reasons.
>>>>> I'm kind of looking for something that is similar to OGNL (a Java
>>>>> library for expressions).
>>>>>
>>>>> Speed is a plus, ease of integration is a nice-to-have. Low bug
>>>>> density and active community is also a plus.
>>>>
>>>> What kind of expression are you talking about?
>>>
>>> Things along the lines of "request['some_attribute']" or "3 * someValue"
>>> etc... Where I can specify the objects available to act upon ('request'
>>> in the first example, 'someValue' in the second).
>>>
>>> Some method of traversing object graphs would be useful as well.  Like I
>>> said, something similar to OGNL, but for PHP instead.
>>
>> What do you need this for?
> A program I'm writing. What's it to you?

I am someone who could help you solve this problem.

> I've given the specific requirements. ;-)
 
ISTM you want a person writing or finding that software for you without any 
real effort on your part.  If so, you are wrong here; there are smart but 
starving PHP developers out there who you should *pay* for that instead.  
The smiley does not change anything.

> More specifically, it is to ease configuration of my program. The
> expressions are going to be embedded into a DSL (domain-specific
> language) for declaring a part of the business logic.

I would suggest you look more into the features of PHP instead of inventing 
another OGNL-like expression language to be parsed with PHP.  Without 
knowing OGNL [1] well or having used it before, ISTM that many of the things 
that OGNL extends Java syntax with are built into PHP these days.

For example, accessing properties instead of calling methods is facilitated 
with the __get() and __set() magic methods. [2]  PHP 5.4 even allows 
accessing the items of array return values directly, which allows for 
“$root->foo()["bar"]” or “$root->foo()[0]”. [3]  (For PHP 5.3 there can be a 
fallback, line “$root->foo()->items(0)”).

Further inspiration, which is probably going to use closures (introduced in 
PHP 5.3, improved in PHP 5.4 [3]), can be drawn from Microsoft LINQ [4]; 
there is an implementation of that in PHP already [5].  Even if that is not 
useful to you, writing that parser (using PHP's PCRE support [6]) should not 
be too difficult a task.

> I'm trying to avoid using "eval" or forcing someone to write a PHP
> function and reference that function by name.

I can understand that and, JFYI, I had understood that already.

> Most of the time, the expressions are so simple, and only make sense in
> the context they appear in the DSL.

If you say so.


PointedEars
___________
[1] <http://commons.apache.org/ognl/>
[2] <http://php.net/manual/en/language.oop5.magic.php>
[3] <http://php.net/manual/en/migration54.new-features.php>
[4] <http://msdn.microsoft.com/en-us/library/vstudio/bb397926.aspx>
[5] <http://phplinq.codeplex.com/>
[6] <http://php.net/manual/en/book.pcre.php>
-- 
    realism:    HTML 4.01 Strict
    evangelism: XHTML 1.0 Strict
    madness:    XHTML 1.1 as application/xhtml+xml
                                                    -- Bjoern Hoehrmann

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Thread

Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-11-30 15:56 -0800
  Re: Simple expression parser for PHP. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-12-01 18:58 +0100
    Re: Simple expression parser for PHP. Allodoxaphobia <knock_yourself_out@example.net> - 2012-12-01 18:09 +0000
    Re: Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-12-01 11:06 -0800
      Re: Simple expression parser for PHP. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-12-02 12:45 +0100
        Re: Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-12-03 09:28 -0800
          Re: Simple expression parser for PHP. Shake <QUITAESTO@QUITAESTO.NOES> - 2012-12-03 18:44 +0100
            Re: Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-12-03 10:06 -0800
              Re: Simple expression parser for PHP. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-12-03 21:04 +0100
          Re: Simple expression parser for PHP. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-12-03 20:59 +0100
            Re: Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-12-03 12:30 -0800
              Re: Simple expression parser for PHP. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-12-03 23:09 +0100
          Re: Simple expression parser for PHP. The Natural Philosopher <tnp@invalid.invalid> - 2012-12-03 20:39 +0000
            Re: Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-12-03 15:58 -0800
              Re: Simple expression parser for PHP. Jerry Stuckle <jstucklex@attglobal.net> - 2012-12-03 20:50 -0500
                Re: Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-12-03 18:40 -0800
                Re: Simple expression parser for PHP. "M. Strobel" <sorry_no_mail_here@nowhere.dee> - 2012-12-04 09:49 +0100
                Re: Simple expression parser for PHP. The Natural Philosopher <tnp@invalid.invalid> - 2012-12-04 09:34 +0000
                Re: Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-12-04 10:09 -0800
              Re: Simple expression parser for PHP. The Natural Philosopher <tnp@invalid.invalid> - 2012-12-04 03:52 +0000
                Re: Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-12-03 22:24 -0800
              Re: Simple expression parser for PHP. Anders Wegge Keller <wegge@wegge.dk> - 2012-12-04 13:49 +0100
                Re: Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-12-04 10:20 -0800
                Re: Simple expression parser for PHP. Anders Wegge Keller <wegge@wegge.dk> - 2012-12-04 19:52 +0100
            Re: Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-12-03 17:18 -0800
              Re: Simple expression parser for PHP. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-12-04 11:55 +0100
                Re: Simple expression parser for PHP. Tim Streater <timstreater@greenbee.net> - 2012-12-04 10:58 +0000
                Re: Simple expression parser for PHP. Scott Johnson <noonehome@chalupasworld.com> - 2012-12-04 05:54 -0800
                Re: Simple expression parser for PHP. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-12-04 15:29 +0100
                Re: Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-12-04 10:25 -0800
                Re: Simple expression parser for PHP. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-12-04 23:23 +0100
                Re: Simple expression parser for PHP. Scott Johnson <noonehome@chalupasworld.com> - 2012-12-04 23:58 -0800
                Re: Simple expression parser for PHP. Jerry Stuckle <jstucklex@attglobal.net> - 2012-12-04 10:36 -0500
                Re: Simple expression parser for PHP. The Natural Philosopher <tnp@invalid.invalid> - 2012-12-05 09:24 +0000
                Re: Simple expression parser for PHP. Scott Johnson <noonehome@chalupasworld.com> - 2012-12-06 16:53 -0800
  Re: Simple expression parser for PHP. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-12-10 09:40 -0800

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