Executing prolog code on an iPhone

Question

Hello,

I currently have the need to execute prolog code in an application I am making. I am aware that Apple probably never would allow something like this in the App Store, but that is not the intention either. This is more a private project that will never reach the App Store.

Purpose

In this case prolog is used to describe an object (like for example a telephone) and its properties. The object will be drawn with OpenGL using coordinates specified in the prolog script. The reason for using prolog is that I need the ability to query the program about some of the features this object has, and prolog eases this a lot. Bottom line: I "need" to query a prolog script from my app.

Possible solutions

• Embed an already existing implementation written in C. I am unsure if this will even work.
• Execute the prolog code on another machine and use the network to query prolog.
• It seems that it is possible to run some sort Ruby VM inside the app (shinycocos uses this as far as I understand), could this be used to run one of the Ruby Prolog implementations?
• Find some alternative to Prolog. This needs to give me some of the same possibilities I get with prolog.

Sadly, google gives me close to no results at all, so I have a feeling that I might be quite alone on this project. If anyone have any experience or clue at all, I would be very thankful.

Answer 1

You can download SWI-Prolog's source code and compile it with XCODE for iOS platform. I've never done that, but it's certainly technically possible.

Once you do that, there are a lot of examples on how to run prolog code from C/C++, hence, you will be able to run prolog from Objective-C.

Answer 2

Having faced similar difficulties calling prolog code, albeit in a different situation, I'd recommend checking out the castor c++ library. This allows you to write logic paradigm code in native c++ without needing to extend the language at all. As castor is a header only library it is easy to compile wherever c++ is available.
Castor website: http://www.mpprogramming.com/cpp/default.aspx