Is there a way to load an external pl file and run it from rust with swipl-rs?

[tumluliu]

Hi there, thanks for making such a crate. I am wondering if there is such a use case supported by swipl-rs? Or it's totally not designed for that? I have asked the same question already to GPT-4, but it's still providing unusable code snippets even after more than 10 iterates.

Here is the latest version it gave me:

extern crate swipl;

use swipl::prelude::*;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let input_data = "john"; // The variable data we want to pass to Prolog program

    // Initialize SWI-Prolog environment
    swipl::init::initialize_swipl()?;
    let activation = swipl::init::activate_engine()?;

    // Consult Prolog program
    let consult_result = {
        let functor = swipl::functor::Functor::new("consult", 1)?;
        let module = swipl::module::Module::new("user")?;
        let pred = swipl::predicate::Predicate::new(functor, module);
        let context = swipl::context::Context::new(activation);
        let term = term!(context, "simple_swipl.pl");
        let mut query = swipl::callable::OpenQuery::new_with_term(activation, &pred, &[term])?;
        query.next()?
    };

    if consult_result.is_none() {
        eprintln!("Failed to consult Prolog file");
        return Ok(());
    }

    // Define Prolog query: grandparent(john, Grandchild)
    let query_string = format!("grandparent('{}', Grandchild)", input_data);
    let call_functor = swipl::functor::Functor::new("call", 1)?;
    let module = swipl::module::Module::new("user")?;
    let pred = swipl::predicate::Predicate::new(call_functor, module);
    let context = swipl::context::Context::new(activation);
    let query_term = term!(context, &query_string);
    let mut query = swipl::callable::OpenQuery::new_with_term(activation, &pred, &[query_term])?;

    // Run the query
    match query.next()? {
        Some(_) => {
            // Get the result
            let grandchild = query.get("Grandchild")?;
            let grandchild_str = grandchild.as_string()?.to_string_lossy().into_owned();

            println!("SWI-Prolog output: {}", grandchild_str);
        }
        None => {
            println!("No result found");
        }
    }

    Ok(())
}

where there are multiple apparent errors. I can fix some of them, but for the statement like let term = term!(context, "simple_swipl.pl");, I have no idea if it makes any sense.

And the minimal sample simple_swipl.pl:

% simple_swipl.pl
parent(john, jim).
parent(jane, jim).
parent(jim, ann).

grandparent(X, Z) :- parent(X, Y), parent(Y, Z).

Looking forward to hearing suggestions from you experts. Thanks a lot!