@obinexusltd/prolog-polycall

SWI-Prolog source binding for libpolycall 1.5, packaged for public distribution through npmjs.org.

The binding is a thin adapter. A Prolog predicate calls one SWI-Prolog foreign predicate, which marshals the configuration path as UTF-8 and forwards it to polycall_ffi_run_config(config_path, 1). Configuration parsing and runtime behavior remain in libpolycall.

Install from npm

npm install @obinexusltd/prolog-polycall

This is a native source package. It includes Prolog and C sources, generated and public headers, examples, tests, scripts, Makefile, configuration, and the binding manifest. It excludes platform- and ABI-specific foreign libraries.

Prolog API

:- use_module('node_modules/@obinexusltd/prolog-polycall/src/prolog_polycall').

run_service :-
    prolog_polycall:run_config('prolog-polycallrc', Status),
    Status =:= 0.

For exception-oriented startup logic:

run_service :-
    catch(
        prolog_polycall:run_config_or_throw('prolog-polycallrc'),
        error(polycall_error(Status), _),
        format(user_error, 'libpolycall status: ~d~n', [Status])
    ).

Exported predicates:

• run_config(-Status) uses prolog-polycallrc.
• run_config(+ConfigPath, -Status) returns the core status unchanged.
• run_config_or_throw/0 uses the default configuration.
• run_config_or_throw(+ConfigPath) throws error(polycall_error(Status), Context) for nonzero status.

Atoms and strings are accepted as configuration paths and marshalled as UTF-8.

Build and test

The native adapter can be built and tested without SWI-Prolog:

npm run build
npm test

This machine currently has GCC and GNU Make but no Prolog implementation. Therefore the native mock contract test, thin-boundary audit, and npm package tests run, while the SWI-Prolog foreign-interface smoke test is reported as skipped. When swipl and swipl-ld are on PATH, it runs automatically.

Run it explicitly after installing SWI-Prolog:

npm run test:prolog

The native test proves exact path forwarding, validation mode 1, and status preservation. The PL-Unit suite then verifies default and explicit paths plus structured errors through the actual foreign interface.

Link with libpolycall

Build libpolycall, then provide its linker flags:

make foreign POLYCALL_LDFLAGS="-LC:/path/to/libpolycall/lib -lpolycall"

This invokes swipl-ld and writes the loadable foreign library under lib/. Add that directory to SWI-Prolog's foreign search path when running:

swipl -p foreign=lib -s examples/basic.pl -- prolog-polycallrc

On Windows, the Makefile links directly with GCC instead of swipl-ld because the latter can split an installation path containing Program Files. It uses C:/PROGRA~1/swipl by default; override SWI_HOME if SWI-Prolog is installed elsewhere.

JavaScript build-tool entry point

const binding = require('@obinexusltd/prolog-polycall');

console.log(binding.prologModule);
console.log(binding.directories.src.relativeFiles);
console.log(binding.resolve('examples', 'basic.pl'));

All package directory metadata is project-relative. The CommonJS entry point indexes src, include, generated, dist, examples, tests, and scripts; resolve() rejects traversal outside the selected directory.

Publish publicly

npm pack --dry-run
npm publish --access public

publishConfig.access is already public. Publishing is not automatic.

Author and license

Nnamdi Michael Okpala ([email protected]). Licensed under MIT.