Prolog Syntax Thingy

This is a simple Prolog program that checks if a tiny part of a Prolog code is correct. It's not fancy, but it does something. It was done for my EIEC4E Theoretical Informatics project.

What It Does

It checks if a string is like likes(john, mary)., parent(foo, bar). or has(item)., using a Finite State Machine (FSM) to validate the structure.

How to Use

1. Make sure you have SWI-Prolog installed.
2. Save the validator.pl file somewhere.
3. Open SWI-Prolog and run ?- consult('validator.pl').
4. To test it, run ?- test1. or ?- test2. or ?- test3. or ?- test4. or ?- test5. or ?- test6. or ?- test7.
5. To test a specific case of a token list you can run something like:
   ?- tokenize("likes(john,mary).", Tokens), validate(Tokens), write("correct"), nl.
   or
   ?- tokenize("parent(john,mary).", Tokens), validate(Tokens), write("correct"), nl.

What's Inside

• It uses a Finite State Machine (FSM) with over 10 states to model the valid syntax of Prolog facts.
• The program uses predicates with variables for its tokenization and validation logic, and the predicates now are core to the logic of the program.
• The FSM is implemented using transition/3, with an initial state of start and a final state of end.

Caveats

• It's still basic.
• It only checks a limited subset of Prolog syntax.
• The tokenizer only accepts a few predefined strings.
• Error messages are simple, and not all types of errors may be handled explicitly.

Cool, can I contribute?

Please don't.

That's it. Have fun.