OOPLib

The prolog.oop library, bridging the JVM/Kotlin object world with Prolog terms via reflection.

Loading this it.unibo.tuprolog.solve.library.Library (e.g. via Runtime.of(OOPLib), see it.unibo.tuprolog.solve.library.Runtime) into a it.unibo.tuprolog.solve.Solver lets Prolog clauses create JVM/Kotlin objects, invoke their (possibly overloaded) methods and constructors, read and write their properties, and convert values back and forth between the two worlds -- all without writing any custom Primitive by hand. This is what makes it possible, for instance, to script the standard library or any third-party JVM class directly from Prolog: new_object('java.util.ArrayList', [], L), L.add(1).

The library contributes:

• primitives: it.unibo.tuprolog.solve.libs.oop.primitives.NewObject3 (new_object/3), it.unibo.tuprolog.solve.libs.oop.primitives.InvokeMethod (invoke_method/3), it.unibo.tuprolog.solve.libs.oop.primitives.InvokeStrict (invoke_strict/3), it.unibo.tuprolog.solve.libs.oop.primitives.Assign (assign/3), it.unibo.tuprolog.solve.libs.oop.primitives.Cast (cast/3), it.unibo.tuprolog.solve.libs.oop.primitives.Type (type/2), the *_items/2 family (it.unibo.tuprolog.solve.libs.oop.primitives.ArrayItems, it.unibo.tuprolog.solve.libs.oop.primitives.ListItems, it.unibo.tuprolog.solve.libs.oop.primitives.SetItems), the type testers (it.unibo.tuprolog.solve.libs.oop.primitives.Ref, it.unibo.tuprolog.solve.libs.oop.primitives.ObjectRef, it.unibo.tuprolog.solve.libs.oop.primitives.TypeRef, it.unibo.tuprolog.solve.libs.oop.primitives.NullRef), and alias management (it.unibo.tuprolog.solve.libs.oop.primitives.Register, it.unibo.tuprolog.solve.libs.oop.primitives.Unregister);

• clauses: the fluent-syntax sugar built on top of the primitives above (:=/2, ./2, new_object/2, fluent_reduce/2, property_reduce/3) plus a battery of default it.unibo.tuprolog.solve.libs.oop.rules.Alias facts for common types (string, array, list, int, big_integer, ... and, on the JVM only, system, math, stdout, stderr, stdin; the JS target contributes no platform-specific alias);

• operators: ./2 (xfy, 800), :=/2 (xfx, 850), as/2 (xfx, 200) and $/1 (fx, 100), which together enable the fluent Prolog syntax documented on it.unibo.tuprolog.solve.libs.oop.rules.ColonEquals and it.unibo.tuprolog.solve.libs.oop.rules.Dot.

Reflection-based method/constructor invocation (everything beyond alias/type-name resolution) is only implemented on the JVM target: see the platform notes on it.unibo.tuprolog.solve.libs.oop.allSupertypes, it.unibo.tuprolog.solve.libs.oop.fullName and the other expect declarations in TypeUtils.kt for what throws kotlin.NotImplementedError on Kotlin/JS.

See also