My application need to do some math operations on some data. Since theese operations are going to change very often, I was thinking of using an interpreted language and let the user write them.
I see that PHP has both LUA and a sort of JS parser, however the documentations is very poor.
Are there any interpreted languages that can be parsed from PHP? I only need basic if-then-else and math operators
Even if there is no much documentation, I'll go for LUA, using the install script found here https://github.com/chtombleson/php-lua-install-script
Other languages supported are listed here http://pecl.php.net/packages.php?catpid=59&catname=Languages
I know it's a bit late to respond to this, but...
Dealing with customizable user logic and not finding an easy, ready-to-go solution, was the exact reason why I just went ahead and created my own scripting language, called Primi.
Written purely in PHP, sandboxed in and interpreted by PHP. Done without dependencies on some external binaries and/or libraries, or any fancy, non-standard PHP extensions.
I mean, phpv8/v8js is pretty great (and looks like they've done a lot of work in the last 2 years), but the getting-it-to-work part was pretty rough for me - at least at the time, when I was doing my research about existing scripting solutions (and with my limited knowledge of Linux stuff back then). Downloading and compiling Google's V8, configuring a compiling the extension, and then finally getting it to work - that's not even an option sometimes, if you don't have absolute control over your machine (cloud hosting and stuff).
Primi most definitely is very, very inferior to any full-pledged scripting/programming language like PHP, JS, Python, etc. - both by features and by performance (it _is_ interpreted by PHP).
Primi's aim is not to do complex stuff - to have OOP, support classes, async stuff or whatnot (at least not right now) - but rather to provide a simple way for a developer to allow his/her clients to write custom logic (calculations, conditions, loops, string manipulations, etc.) that could be safely executed inside Primi's interpreter, which itself is executed by PHP and thus confined within PHP's own VM.
And all that without making any changes to the surrounding environment (OS-wide installing binaries, compiling libraries).
Primi can be installed as a Composer package and then used instantly:
composer require smuuf/primi
And that's it for the installation process.
The interpreter can be then used like this:
$context = new \Smuuf\Primi\Context;
$interpreter = new \Smuuf\Primi\Interpreter($context);
try {
// Let the interpreter run a source code.
$interpreter->run('a = 1; b = a + 2; c = "some string"; d = c + " extra thing";');
// Get defined variables from primary context and print them.
foreach ($context->getVariables() as $name => $value) {
printf("%s (%s) ... %s\n", $name, $value::TYPE, $value->getInternalValue());
}
} catch (\Smuuf\Primi\ErrorException $e) {
die($e->getMessage());
}
Running this code in PHP would result in this:
a (number) ... 1
b (number) ... 3
c (string) ... some string
d (string) ... some string extra thing
I am the author of this
If you find any bugs to report, have suggestions for new features, or you just want to see how it works or want to help, you can find everything else here: https://github.com/smuuf/primi.
I would probably have made this a comment, but it's a bit too long and it's technically ALMOST an answer :-p
If you want the absolute simplest approach for your users...where the user enters an equation and then you are responsible to utilize the equation on subsequent pages...then you can do string parsing.
So, for instance, you would find all text-characters in a string and convert them into inputs. So, with the equation, "2x", you would create a single input: 2<input name='x' /> Then, on post, you convert 2x into:
$result = floatval(2) * floatval($_GET['x']);
Something like this is pretty safe so long as you do not trust either the equation nor the user input as PHP code...ensure the right types, etc. However, depending on your experience, parsing the string correctly and turning 2y into 2 * y, etc., is going to be your challenge, and more than I can answer given time.
the point on MathML is that if you can take the user's equation and convert it into MathML, you may be able to take advantage of other people's work for processing the equation. The point in my comment was not to make the user utilize MathML themselves...that's your job :)
