commonMain.it.unibo.tuprolog.solve.primitive.BinaryRelation.kt Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of solve-jvm Show documentation

Resolution-agnostic API for logic solvers

There is a newer version: 1.0.4

package it.unibo.tuprolog.solve.primitive

import it.unibo.tuprolog.core.Substitution
import it.unibo.tuprolog.core.Term
import it.unibo.tuprolog.solve.ExecutionContext

/** Base class to implement primitives that relate two [Term]s and provide a single response */
abstract class BinaryRelation(operator: String) : PrimitiveWrapper(operator, 2) {
    /** Template method aimed at computing the application of this relation to three [Term]s */
    protected abstract fun Solve.Request.computeAll(
        first: Term,
        second: Term,
    ): Sequence

    final override fun uncheckedImplementation(request: Solve.Request): Sequence {
        return request.computeAll(request.arguments[0], request.arguments[1])
    }

    abstract class WithoutSideEffects(operator: String) : BinaryRelation(operator) {
        protected abstract fun Solve.Request.computeAllSubstitutions(
            first: Term,
            second: Term,
        ): Sequence

        final override fun Solve.Request.computeAll(
            first: Term,
            second: Term,
        ): Sequence {
            return computeAllSubstitutions(first, second).map { replyWith(it) }
        }
    }

    abstract class NonBacktrackable(operator: String) : BinaryRelation(operator) {
        protected abstract fun Solve.Request.computeOne(
            first: Term,
            second: Term,
        ): Solve.Response

        final override fun Solve.Request.computeAll(
            first: Term,
            second: Term,
        ): Sequence {
            return sequenceOf(computeOne(first, second))
        }
    }

    abstract class Functional(operator: String) : NonBacktrackable(operator) {
        protected abstract fun Solve.Request.computeOneSubstitution(
            first: Term,
            second: Term,
        ): Substitution

        final override fun Solve.Request.computeOne(
            first: Term,
            second: Term,
        ): Solve.Response {
            return replyWith(computeOneSubstitution(first, second))
        }
    }

    abstract class Predicative(operator: String) : NonBacktrackable(operator) {
        protected abstract fun Solve.Request.compute(
            first: Term,
            second: Term,
        ): Boolean

        final override fun Solve.Request.computeOne(
            first: Term,
            second: Term,
        ): Solve.Response {
            return if (compute(first, second)) replySuccess() else replyFail()
        }
    }
}