tdpeuter/2025LogProg-project-GhentProlog
tdpeuter/2025LogProg-project-GhentProlog
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Cleanup 2

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This commit is contained in:
Tibo De Peuter 2025-05-09 18:30:18 +02:00
parent a9bb6e0338
commit 3c938749d0
Signed by: tdpeuter
GPG key ID: 38297DE43F75FFE2
22 changed files with 299 additions and 110 deletions
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4
src/interpreter/Preprocessor.kt
View file

@ -3,7 +3,6 @@ package interpreter
import io.Logger
import prolog.ast.arithmetic.Expression
import prolog.ast.arithmetic.Integer
import prolog.ast.lists.List as PList
import prolog.ast.logic.Clause
import prolog.ast.logic.Fact
import prolog.ast.logic.LogicOperand
@ -156,7 +155,8 @@ open class Preprocessor {
Functor.of("read/1") -> Read(args[0])
// Lists
Functor.of("member/2") -> Member(args[0], args[1] as PList)
Functor.of("member/2") -> Member(args[0], args[1])
Functor.of("append/3") -> Append(args[0], args[1], args[2])
// Meta
Functor.of("call/1") -> Call(args[0])

5
src/prolog/ast/arithmetic/ArithmeticOperator.kt
View file

@ -4,4 +4,7 @@ import prolog.ast.terms.Atom
import prolog.ast.terms.Operator
abstract class ArithmeticOperator(symbol: Atom, leftOperand: Expression, rightOperand: Expression) :
Operator(symbol, leftOperand, rightOperand), Expression
Operator(symbol, leftOperand, rightOperand), Expression {
constructor(symbol: String, leftOperand: Expression, rightOperand: Expression) :
this(Atom(symbol), leftOperand, rightOperand)
}

18
src/prolog/ast/lists/List.kt
View file

@ -6,11 +6,18 @@ import prolog.ast.arithmetic.Integer
sealed class List : Term {
abstract val head: Term
open val tail: List? = null
open val tail: Term? = null
operator fun component1(): Term = head
operator fun component2(): Term? = tail
val size: Integer
get() = when (this) {
is Empty -> Integer(0)
is Cons -> Integer(1 + tail.size.value)
is Cons -> {
val tailSize = if (tail is List) { (tail as List).size.value } else 0
Integer(1 + tailSize)
}
}
fun isEmpty(): Boolean = this is Empty
@ -24,7 +31,7 @@ sealed class List : Term {
override fun toString(): String = "[]"
}
class Cons(override val head: Term, override var tail: List) : List() {
class Cons(override val head: Term, override var tail: Term) : List() {
override fun applySubstitution(subs: Substitutions): List {
val newHead = head.applySubstitution(subs)
val newTail = tail.applySubstitution(subs) as List
@ -33,11 +40,12 @@ sealed class List : Term {
override fun toString(): String {
val values = mutableListOf<Term>()
var current: List? = this
while (current != null && current !is Empty) {
var current: Term? = this
while (current != null && current is Cons) {
values.add(current.head)
current = current.tail
}
if (current != null && current !is Empty) values.add(current)
return "[${values.joinToString(", ")}]"
}
}

3
src/prolog/ast/logic/LogicOperator.kt
View file

@ -10,5 +10,8 @@ abstract class LogicOperator(
leftOperand: LogicOperand? = null,
rightOperand: LogicOperand
) : Operator(symbol, leftOperand, rightOperand), Satisfiable {
constructor(symbol: String, leftOperand: LogicOperand? = null, rightOperand: LogicOperand) :
this(Atom(symbol), leftOperand, rightOperand)
abstract override fun satisfy(subs: Substitutions): Answers
}

3
src/prolog/ast/terms/Operator.kt
View file

@ -7,6 +7,9 @@ abstract class Operator(
private val leftOperand: Operand? = null,
private val rightOperand: Operand
) : CompoundTerm(symbol, listOfNotNull(leftOperand, rightOperand)), Term {
constructor(symbol: String, leftOperand: Operand? = null, rightOperand: Operand) :
this(Atom(symbol), leftOperand, rightOperand)
override fun toString(): String {
return when (leftOperand) {
null -> "${symbol.name} $rightOperand"

2
src/prolog/ast/terms/Structure.kt
View file

@ -12,6 +12,8 @@ typealias Argument = Term
typealias CompoundTerm = Structure
open class Structure(val name: Atom, var arguments: List<Argument>) : Goal(), Head, Body, Resolvent {
constructor(name: String, vararg arguments: Argument) : this(Atom(name), arguments.asList())
override val functor: Functor = Functor(name, Integer(arguments.size))
override fun solve(goal: Goal, subs: Substitutions): Answers {

17
src/prolog/builtins/analysisOperators.kt
View file

@ -21,7 +21,7 @@ import prolog.ast.lists.List.Cons
* Source: [SWI-Prolog Predicate functor/3](https://www.swi-prolog.org/pldoc/doc_for?object=functor/3)
*/
class FunctorOp(private val term: Term, private val functorName: Term, private val functorArity: Term) :
Structure(Atom("functor"), listOf(term, functorName, functorArity)) {
Structure("functor", term, functorName, functorArity) {
override fun satisfy(subs: Substitutions): Answers {
return when {
nonvariable(term, subs) -> {
@ -57,7 +57,7 @@ class FunctorOp(private val term: Term, private val functorName: Term, private v
}
class Arg(private val arg: Term, private val term: Term, private val value: Term) :
Structure(Atom("arg"), listOf(arg, term, value)) {
Structure("arg", arg, term, value) {
override fun satisfy(subs: Substitutions): Answers = sequence {
require(nonvariable(term, subs)) { "Arguments are not sufficiently instantiated" }
require(compound(term, subs)) {
@ -118,7 +118,7 @@ class Arg(private val arg: Term, private val term: Term, private val value: Term
* [SWI-Prolog Operator clause/2](https://www.swi-prolog.org/pldoc/doc_for?object=clause/2)
*/
class ClauseOp(private val head: Head, private val body: Body) :
Structure(Atom("clause"), listOf(head, body)) {
Structure("clause", head, body) {
override fun satisfy(subs: Substitutions): Answers = sequence {
require(nonvariable(head, subs)) { "Arguments are not sufficiently instantiated" }
@ -157,7 +157,7 @@ class ClauseOp(private val head: Head, private val body: Body) :
)
}
open class Univ(private val term: Term, private val list: Term) : Operator(Atom("=.."), term, list) {
open class Univ(private val term: Term, private val list: Term) : Operator("=..", term, list) {
override fun satisfy(subs: Substitutions): Answers {
return when {
nonvariable(term, subs) && nonvariable(list, subs) -> {
@ -189,11 +189,14 @@ open class Univ(private val term: Term, private val list: Term) : Operator(Atom(
list.size.value > 1 -> {
val head = list.head
val arguments = mutableListOf<Term>()
var tail: List? = list.tail
while (tail != null && tail !is Empty) {
var tail: Term? = list.tail
while (tail != null && tail is Cons) {
arguments.add(tail.head)
tail = tail.tail
}
if (tail != null && tail !is Empty) {
arguments.add(tail)
}
Structure(head as Atom, arguments)
}
@ -227,7 +230,7 @@ open class Univ(private val term: Term, private val list: Term) : Operator(Atom(
}
class NumberVars(private val term: Term, private val start: Integer, private val end: Term) :
Structure(Atom("numbervars"), listOf(term, start, end)) {
Structure("numbervars", term, start, end) {
private var yieldEnd: Boolean = true
constructor(term: Term) : this(term, Integer(0), AnonymousVariable.create()) {

18
src/prolog/builtins/arithmeticOperators.kt
View file

@ -22,7 +22,7 @@ import prolog.logic.*
* True if expression Expr1 evaluates to a number non-equal to Expr2.
*/
class EvaluatesToDifferent(private val left: Expression, private val right: Expression) :
Operator(Atom("=\\="), left, right), Satisfiable {
Operator("=\\=", left, right), Satisfiable {
override fun satisfy(subs: Substitutions): Answers {
val t1 = left.simplify(subs)
val t2 = right.simplify(subs)
@ -49,7 +49,7 @@ class EvaluatesToDifferent(private val left: Expression, private val right: Expr
* True if Expr1 evaluates to a number equal to Expr2.
*/
class EvaluatesTo(private val left: Expression, private val right: Expression) :
Operator(Atom("=:="), left, right) {
Operator("=:=", left, right) {
override fun satisfy(subs: Substitutions): Answers {
val t1 = left.simplify(subs)
val t2 = right.simplify(subs)
@ -72,7 +72,7 @@ class EvaluatesTo(private val left: Expression, private val right: Expression) :
* True when Number is the value to which Expr evaluates.
*/
class Is(val number: Expression, val expr: Expression) :
Operator(Atom("is"), number, expr), Satisfiable {
Operator("is", number, expr), Satisfiable {
override fun satisfy(subs: Substitutions): Answers {
val t1 = number.simplify(subs)
val t2 = expr.simplify(subs)
@ -108,7 +108,7 @@ class Positive(operand: Expression) : Add(Integer(0), operand)
* Result = Expr1 + Expr2
*/
open class Add(private val expr1: Expression, private val expr2: Expression) :
ArithmeticOperator(Atom("+"), expr1, expr2) {
ArithmeticOperator("+", expr1, expr2) {
override fun simplify(subs: Substitutions): Simplification {
val result = Variable("Result")
val map = plus(expr1, expr2, result, subs)
@ -126,7 +126,7 @@ open class Add(private val expr1: Expression, private val expr2: Expression) :
* Result = Expr1 - Expr2
*/
open class Subtract(private val expr1: Expression, private val expr2: Expression) :
ArithmeticOperator(Atom("-"), expr1, expr2) {
ArithmeticOperator("-", expr1, expr2) {
override fun simplify(subs: Substitutions): Simplification {
val result = Variable("Result")
val map = plus(expr2, result, expr1, subs)
@ -144,7 +144,7 @@ open class Subtract(private val expr1: Expression, private val expr2: Expression
* Result = Expr1 * Expr2
*/
class Multiply(val expr1: Expression, val expr2: Expression) :
ArithmeticOperator(Atom("*"), expr1, expr2) {
ArithmeticOperator("*", expr1, expr2) {
override fun simplify(subs: Substitutions): Simplification {
val result = Variable("Result")
val map = mul(expr1, expr2, result, subs)
@ -159,7 +159,7 @@ class Multiply(val expr1: Expression, val expr2: Expression) :
}
class Divide(private val expr1: Expression, private val expr2: Expression) :
ArithmeticOperator(Atom("/"), expr1, expr2) {
ArithmeticOperator("/", expr1, expr2) {
override fun simplify(subs: Substitutions): Simplification {
val result = Variable("Result")
val map = div(expr1, expr2, result, subs)
@ -178,7 +178,7 @@ class Divide(private val expr1: Expression, private val expr2: Expression) :
// TODO Expr rem Expr
class Between(private val expr1: Expression, private val expr2: Expression, private val expr3: Expression) :
CompoundTerm(Atom("between"), listOf(expr1, expr2, expr3)), Satisfiable {
CompoundTerm("between", expr1, expr2, expr3), Satisfiable {
override fun satisfy(subs: Substitutions): Answers {
val e1 = expr1.simplify(subs)
val e2 = expr2.simplify(subs)
@ -210,6 +210,6 @@ class Between(private val expr1: Expression, private val expr2: Expression, priv
}
class Successor(private val expr1: Expression, private val expr2: Expression) :
CompoundTerm(Atom("succ"), listOf(expr1, expr2)), Satisfiable {
CompoundTerm("succ", expr1, expr2), Satisfiable {
override fun satisfy(subs: Substitutions): Answers = succ(expr1, expr2, subs)
}

6
src/prolog/builtins/controlOperators.kt
View file

@ -48,7 +48,7 @@ class Cut() : Atom("!") {
* Conjunction (and). True if both Goal1 and Goal2 are true.
*/
open class Conjunction(val left: LogicOperand, private val right: LogicOperand) :
LogicOperator(Atom(","), left, right) {
LogicOperator(",", left, right) {
override fun satisfy(subs: Substitutions): Answers = sequence {
fun satisfyRight(leftSubs: Substitutions): Answers = sequence {
right.satisfy(subs + leftSubs).forEach { right ->
@ -123,7 +123,7 @@ open class Conjunction(val left: LogicOperand, private val right: LogicOperand)
* Disjunction (or). True if either Goal1 or Goal2 succeeds.
*/
open class Disjunction(private val left: LogicOperand, private val right: LogicOperand) :
LogicOperator(Atom(";"), left, right) {
LogicOperator(";", left, right) {
override fun satisfy(subs: Substitutions): Answers = sequence {
left.satisfy(subs).forEach { left ->
left.fold(
@ -158,7 +158,7 @@ class Bar(leftOperand: LogicOperand, rightOperand: LogicOperand) : Disjunction(l
/**
* True if 'Goal' cannot be proven.
*/
class Not(private val goal: Goal) : LogicOperator(Atom("\\+"), rightOperand = goal) {
open class Not(private val goal: Goal) : LogicOperator("\\+", rightOperand = goal) {
override fun satisfy(subs: Substitutions): Answers {
// If the goal can be proven, return an empty sequence
val goalResults = goal.satisfy(subs).iterator()

6
src/prolog/builtins/databaseOperators.kt
View file

@ -49,7 +49,7 @@ class Assert(clause: Clause) : AssertZ(clause) {
/**
* Assert a [Clause] as a first clause of the [Predicate] into the [Program].
*/
class AssertA(val clause: Clause) : Operator(Atom("asserta"), null, clause) {
class AssertA(val clause: Clause) : Operator("asserta", rightOperand = clause) {
override fun satisfy(subs: Substitutions): Answers {
// Add clause to the program
val evaluatedClause = applySubstitution(clause, subs) as Clause
@ -64,7 +64,7 @@ class AssertA(val clause: Clause) : Operator(Atom("asserta"), null, clause) {
/**
* Assert a [Clause] as a last clause of the [Predicate] into the [Program].
*/
open class AssertZ(val clause: Clause) : Operator(Atom("assertz"), null, clause) {
open class AssertZ(val clause: Clause) : Operator("assertz", rightOperand = clause) {
override fun satisfy(subs: Substitutions): Answers {
// Add clause to the program
val evaluatedClause = applySubstitution(clause, subs) as Clause
@ -82,7 +82,7 @@ open class AssertZ(val clause: Clause) : Operator(Atom("assertz"), null, clause)
*
* @see [SWI-Prolog Predicate retract/1](https://www.swi-prolog.org/pldoc/doc_for?object=retract/1)
*/
open class Retract(val term: Term) : Operator(Atom("retract"), null, term) {
open class Retract(val term: Term) : Operator("retract", rightOperand = term) {
override fun satisfy(subs: Substitutions): Answers = sequence {
// Check that term is a structure or atom
if (term !is Structure && term !is Atom) {

4
src/prolog/builtins/delimitedContinuationsOperators.kt
View file

@ -23,7 +23,7 @@ import prolog.logic.unifyLazy
* return, unifying Cont with a Goal that represents the continuation after shift.
*/
class Reset(private val goal: Goal, private val ball: Term, private val cont: Term) :
Structure(Atom("reset"), listOf(goal, ball, cont)) {
Structure("reset", goal, ball, cont) {
override fun satisfy(subs: Substitutions): Answers = sequence {
goal.satisfy(subs).forEach { goalResult ->
goalResult.fold(
@ -63,7 +63,7 @@ class Reset(private val goal: Goal, private val ball: Term, private val cont: Te
/**
* Variables that have been bound during the procedure called by reset/3 stay bound after a shift/1:
*/
class Shift(private val ball: Term) : Structure(Atom("shift"), listOf(ball)) {
class Shift(private val ball: Term) : Structure("shift", ball) {
override fun satisfy(subs: Substitutions): Answers = sequence {
val shift = AppliedShift(
subs = subs,

2
src/prolog/builtins/ioOperators.kt
View file

@ -16,7 +16,7 @@ import prolog.logic.unifyLazy
/**
* Write [Term] to the current output, using brackets and operators where appropriate.
*/
class Write(private val term: Term) : Operator(Atom("write"), null, term), Satisfiable {
class Write(private val term: Term) : Operator("write", rightOperand = term), Satisfiable {
constructor(message: String) : this(Atom(message))
override fun satisfy(subs: Substitutions): Answers {

56
src/prolog/builtins/listOperators.kt
View file

@ -5,18 +5,28 @@ import prolog.Substitutions
import prolog.ast.lists.List
import prolog.ast.lists.List.Cons
import prolog.ast.lists.List.Empty
import prolog.ast.terms.Atom
import prolog.ast.terms.Body
import prolog.ast.terms.Operator
import prolog.ast.terms.Structure
import prolog.ast.terms.Term
import prolog.ast.terms.Variable
import prolog.logic.applySubstitution
import prolog.logic.unifyLazy
class Member(private val element: Term, private val list: List) : Operator(Atom("member"), element, list) {
private var solution: Operator = when (list) {
is Empty -> Disjunction(Fail, Fail)
class Member(private val element: Term, private val list: Term) : Operator("member", element, list) {
private var solution: Body = when (list) {
is Empty -> Fail
is Cons -> Disjunction(
Unify(element, list.head),
Member(element, list.tail)
)
else -> {
// Generate a sequence of lists that have anonymous variables in them.
// Place element at each index
// TODO Fix this
Unify(element, list)
}
}
override fun satisfy(subs: Substitutions): Answers = solution.satisfy(subs)
@ -28,3 +38,41 @@ class Member(private val element: Term, private val list: List) : Operator(Atom(
override fun toString(): String = "$element ∈ $list"
}
class Append(private val list1: Term, private val list2: Term, private val list3: Term) :
Structure("append", list1, list2, list3) {
override fun satisfy(subs: Substitutions): Answers = sequence {
val l1 = applySubstitution(list1, subs)
val l2 = applySubstitution(list2, subs)
val l3 = applySubstitution(list3, subs)
if (l1 is Empty) {
yieldAll(unifyLazy(l2, l3, subs))
}
val head1 = if (l1 is Cons) l1.head else Variable("Head1")
val tail1 = if (l1 is Cons) l1.tail else Variable("Tail1")
val head3 = if (l3 is Cons) l3.head else Variable("Head3")
val tail3 = if (l3 is Cons) l3.tail else Variable("Tail3")
unifyLazy(head1, head3, subs).forEach { headResult ->
headResult.map { headSubs ->
val newSubs = subs + headSubs
Append(tail1, list2, tail3).satisfy(newSubs).forEach { tailResult ->
tailResult.map { tailSubs ->
val result = headSubs + tailSubs
yield(Result.success(result))
}
}
}
}
TODO("This does not return the expected results, especially when using variables for the lists.")
}
override fun applySubstitution(subs: Substitutions): Append = Append(
applySubstitution(list1, subs),
applySubstitution(list2, subs),
applySubstitution(list3, subs)
)
}

4
src/prolog/builtins/metaOperators.kt
View file

@ -9,7 +9,7 @@ import prolog.ast.terms.Term
import prolog.flags.AppliedCut
import prolog.logic.applySubstitution
class Call(private val goal: Term) : Operator(Atom("call"), null, goal) {
class Call(private val goal: Term) : Operator("call", rightOperand = goal) {
override fun satisfy(subs: Substitutions): Answers {
val appliedGoal = applySubstitution(goal, subs) as Goal
return appliedGoal.satisfy(subs)
@ -19,7 +19,7 @@ class Call(private val goal: Term) : Operator(Atom("call"), null, goal) {
/**
* Calls [Goal] once, but succeeds, regardless of whether Goal succeeded or not.
*/
class Ignore(goal: Goal) : Operator(Atom("ignore"), null, goal) {
class Ignore(goal: Goal) : Operator("ignore", rightOperand = goal) {
private val disjunction = Disjunction(
Conjunction(Call(goal), Cut()),
True

14
src/prolog/builtins/other.kt
View file

@ -3,18 +3,15 @@ package prolog.builtins
import prolog.Answers
import prolog.Substitutions
import prolog.ast.logic.LogicOperand
import prolog.ast.terms.Atom
import prolog.ast.logic.LogicOperator
import prolog.ast.terms.Goal
import prolog.ast.terms.Operand
import prolog.ast.terms.Operator
class Initialization(val goal: LogicOperand) : LogicOperator(Atom(":-"), null, goal) {
class Initialization(val goal: LogicOperand) : LogicOperator(":-", rightOperand = goal) {
override fun satisfy(subs: Substitutions): Answers = goal.satisfy(subs).take(1)
override fun toString(): String = goal.toString()
}
class Query(val query: LogicOperand) : LogicOperator(Atom("?-"), null, query) {
class Query(val query: LogicOperand) : LogicOperator("?-", rightOperand = query) {
override fun satisfy(subs: Substitutions): Answers = query.satisfy(subs)
}
@ -24,7 +21,8 @@ class Query(val query: LogicOperand) : LogicOperator(Atom("?-"), null, query) {
*
* @see [SWI-Prolog Predicate forall/2](https://www.swi-prolog.org/pldoc/doc_for?object=forall/2)
*/
class ForAll(condition: LogicOperand, action: Goal) : Operator(Atom("forall"), condition, action) {
private val not = Not(Conjunction(condition, Not(action)))
override fun satisfy(subs: Substitutions): Answers = not.satisfy(subs)
class ForAll(private val condition: LogicOperand, private val action: Goal) :
Not(Conjunction(condition, Not(action))) {
override fun toString() = "forall($condition, $action)"
}

23
src/prolog/builtins/unificationOperators.kt
View file

@ -7,7 +7,6 @@ package prolog.builtins
import prolog.Answers
import prolog.Substitutions
import prolog.ast.terms.Atom
import prolog.ast.terms.Operator
import prolog.ast.terms.Term
import prolog.logic.applySubstitution
@ -17,7 +16,7 @@ import prolog.logic.unifyLazy
/**
* Unify Term1 with Term2. True if the unification succeeds.
*/
class Unify(private val term1: Term, private val term2: Term): Operator(Atom("="), term1, term2) {
class Unify(private val term1: Term, private val term2: Term): Operator("=", term1, term2) {
override fun satisfy(subs: Substitutions): Answers = sequence {
val t1 = applySubstitution(term1, subs)
val t2 = applySubstitution(term2, subs)
@ -31,16 +30,11 @@ class Unify(private val term1: Term, private val term2: Term): Operator(Atom("="
)
}
class NotUnify(private val term1: Term, private val term2: Term) : Operator(Atom("\\="), term1, term2) {
private val not = Not(Unify(term1, term2))
override fun satisfy(subs: Substitutions): Answers = not.satisfy(subs)
override fun applySubstitution(subs: Substitutions): NotUnify = NotUnify(
applySubstitution(term1, subs),
applySubstitution(term2, subs)
)
class NotUnify(private val term1: Term, private val term2: Term) : Not(Unify(term1, term2)) {
override fun toString(): String = "($term1 \\= $term2)"
}
class Equivalent(private val term1: Term, private val term2: Term) : Operator(Atom("=="), term1, term2) {
class Equivalent(private val term1: Term, private val term2: Term) : Operator("==", term1, term2) {
override fun satisfy(subs: Substitutions): Answers = sequence {
val t1 = applySubstitution(term1, subs)
val t2 = applySubstitution(term2, subs)
@ -56,11 +50,6 @@ class Equivalent(private val term1: Term, private val term2: Term) : Operator(At
)
}
class NotEquivalent(private val term1: Term, private val term2: Term) : Operator(Atom("\\=="), term1, term2) {
private val not = Not(Equivalent(term1, term2))
override fun satisfy(subs: Substitutions): Answers = not.satisfy(subs)
override fun applySubstitution(subs: Substitutions): NotEquivalent = NotEquivalent(
applySubstitution(term1, subs),
applySubstitution(term2, subs)
)
class NotEquivalent(private val term1: Term, private val term2: Term) : Not(Equivalent(term1, term2)) {
override fun toString(): String = "($term1 \\== $term2)"
}

15
src/prolog/builtins/verificationOperators.kt
View file

@ -2,16 +2,11 @@ package prolog.builtins
import prolog.Answers
import prolog.Substitutions
import prolog.ast.terms.Atom
import prolog.ast.terms.Operator
import prolog.ast.terms.Term
import prolog.logic.applySubstitution
import prolog.logic.atomic
import prolog.logic.compound
import prolog.logic.nonvariable
import prolog.logic.variable
import prolog.logic.*
class Atomic(private val term: Term) : Operator(Atom("atomic"), null, term) {
class Atomic(private val term: Term) : Operator("atomic", rightOperand = term) {
override fun satisfy(subs: Substitutions): Answers {
if (atomic(term, subs)) {
return sequenceOf(Result.success(emptyMap()))
@ -22,7 +17,7 @@ class Atomic(private val term: Term) : Operator(Atom("atomic"), null, term) {
override fun applySubstitution(subs: Substitutions): Atomic = Atomic(applySubstitution(term, subs))
}
class Compound(private val term: Term) : Operator(Atom("compound"), null, term) {
class Compound(private val term: Term) : Operator("compound", rightOperand = term) {
override fun satisfy(subs: Substitutions): Answers {
if (compound(term, subs)) {
return sequenceOf(Result.success(emptyMap()))
@ -33,7 +28,7 @@ class Compound(private val term: Term) : Operator(Atom("compound"), null, term)
override fun applySubstitution(subs: Substitutions): Compound = Compound(applySubstitution(term, subs))
}
class NonVar(private val term: Term) : Operator(Atom("nonvar"), null, term) {
class NonVar(private val term: Term) : Operator("nonvar", rightOperand = term) {
override fun satisfy(subs: Substitutions): Answers {
if (nonvariable(term, subs)) {
return sequenceOf(Result.success(emptyMap()))
@ -45,7 +40,7 @@ class NonVar(private val term: Term) : Operator(Atom("nonvar"), null, term) {
override fun applySubstitution(subs: Substitutions): NonVar = NonVar(applySubstitution(term, subs))
}
class Var(private val term: Term) : Operator(Atom("var"), null, term) {
class Var(private val term: Term) : Operator("var", rightOperand = term) {
override fun satisfy(subs: Substitutions): Answers {
if (variable(term, subs)) {
return sequenceOf(Result.success(emptyMap()))