Rule

interface Rule: Clause, Any

Fields

Name Description
abstract head: Struct
open isRule: Boolean

Checks whether the current term is a rule, or a fact. This method is guaranteed to return true if and only if the current term is an instance of Rule.

open isFact: Boolean

Checks whether the current term is a fact. This method is guaranteed to return true if and only if the current term is an instance of Fact.

open isDirective: Boolean

Checks whether the current term is a directive. This method is guaranteed to return true if and only if the current term is an instance of Directive.

abstract headArgs: Iterable<Term>
abstract headArity: Int

Methods

freshCopy

abstract fun freshCopy(): Rule

Returns a fresh copy of this Term, that is, an instance of Term which is equal to the current one in any aspect, except variables directly or indirectly contained into this Term, which are refreshed. This means that it could return itself, if no variable is present (ground term), or a new Term with freshly generated variables.

Variables are refreshed consistently, meaning that, if more variables exists within this Term having the same name, all fresh copies of such variables will have the same complete name.

Example: "f(X, g(X))".freshCopy() returns something like "f(X_1, g(X_1))" instead of "f(X_1, g(X_2))"

Notice that, if the current term is ground, the same object may be returned as a result by this method.

ReturnValue

Name Description
Rule

a fresh copy of the current term which is different because variables are consistently renamed

freshCopy

abstract fun freshCopy(scope: Scope): Rule

Returns a fresh copy of this Term, similarly to freshCopy, possibly reusing variables from the provided scope, if any

Parameters

Name Description
scope: Scope

the Scope containing variables to be used in copying

ReturnValue

Name Description
Rule

a fresh copy of the current term which is different because variables are consistently renamed

asRule

open fun asRule(): Rule

Casts the current Term to Rule, if possible, or returns null otherwise

ReturnValue

Name Description
Rule

the current Term, casted to Rule, or null, if the current term is not an instance of Rule

getHeadArg

abstract fun getHeadArg(index: Int): Term

Parameters

Name Description
index: Int

ReturnValue

Name Description
Term

setBody

abstract fun setBody(body: Term): Rule

Parameters

Name Description
body: Term

ReturnValue

Name Description
Rule

setHeadFunctor

abstract fun setHeadFunctor(functor: String): Rule

Parameters

Name Description
functor: String

ReturnValue

Name Description
Rule

setHeadArgs

abstract fun setHeadArgs(vararg arguments: Term): Rule

Parameters

Name Description
vararg arguments: Term

ReturnValue

Name Description
Rule

setHeadArgs

abstract fun setHeadArgs(arguments: Iterable<Term>): Rule

Parameters

Name Description
arguments: Iterable<Term>

ReturnValue

Name Description
Rule

setHeadArgs

abstract fun setHeadArgs(arguments: Sequence<Term>): Rule

Parameters

Name Description
arguments: Sequence<Term>

ReturnValue

Name Description
Rule

insertHeadArg

abstract fun insertHeadArg(index: Int, argument: Term): Rule

Parameters

Name Description
index: Int
argument: Term

ReturnValue

Name Description
Rule

addFirstHeadArg

abstract fun addFirstHeadArg(argument: Term): Rule

Parameters

Name Description
argument: Term

ReturnValue

Name Description
Rule

addLastHeadArg

abstract fun addLastHeadArg(argument: Term): Rule

Parameters

Name Description
argument: Term

ReturnValue

Name Description
Rule

appendHeadArg

abstract fun appendHeadArg(argument: Term): Rule

Parameters

Name Description
argument: Term

ReturnValue

Name Description
Rule

setBodyItems

abstract fun setBodyItems(argument: Term, vararg arguments: Term): Rule

Parameters

Name Description
argument: Term
vararg arguments: Term

ReturnValue

Name Description
Rule

setBodyItems

abstract fun setBodyItems(arguments: Iterable<Term>): Rule

Parameters

Name Description
arguments: Iterable<Term>

ReturnValue

Name Description
Rule

setBodyItems

abstract fun setBodyItems(arguments: Sequence<Term>): Rule

Parameters

Name Description
arguments: Sequence<Term>

ReturnValue

Name Description
Rule

insertBodyItem

abstract fun insertBodyItem(index: Int, argument: Term): Rule

Parameters

Name Description
index: Int
argument: Term

ReturnValue

Name Description
Rule

addFirstBodyItem

abstract fun addFirstBodyItem(argument: Term): Rule

Parameters

Name Description
argument: Term

ReturnValue

Name Description
Rule

addLastBodyItem

abstract fun addLastBodyItem(argument: Term): Rule

Parameters

Name Description
argument: Term

ReturnValue

Name Description
Rule

appendBodyItem

abstract fun appendBodyItem(argument: Term): Rule

Parameters

Name Description
argument: Term

ReturnValue

Name Description
Rule

Extensions

prepareForExecution

fun Clause.prepareForExecution(): Clause

Prepares the receiver Clause for execution, using the provided visitor

For example, the Clause product(A) :- A, A is transformed, after preparation for execution, as the Term: product(A) :- call(A), call(A)

Receiver

Name Description
Clause

ReturnValue

Name Description
Clause

prepareForExecution

fun Clause.prepareForExecution(unifier: Unifier): Clause

Receiver

Name Description
Clause

Parameters

Name Description
unifier: Unifier

ReturnValue

Name Description
Clause

toClause

fun Term.toClause(source: Any?, line: Int, column: Int): Clause

Receiver

Name Description
Term

Parameters

Name Description
source: Any?
line: Int
column: Int

ReturnValue

Name Description
Clause

unfoldGoals

fun Term.unfoldGoals(): Sequence<Term>

Receiver

Name Description
Term

ReturnValue

Name Description
Sequence<Term>

toGoals

fun Term.toGoals(): Cursor<Term>

Receiver

Name Description
Term

ReturnValue

Name Description
Cursor<Term>

isWellFormed

fun Term.isWellFormed(): Boolean

Check whether the receiver term is a well-formed predication

Receiver

Name Description
Term

ReturnValue

Name Description
Boolean

prepareForExecutionAsGoal

fun Term.prepareForExecutionAsGoal(): Struct

Prepares the receiver Goal for execution

For example, the goal A is transformed, after preparation for execution, as the Term: call(A)

Receiver

Name Description
Term

ReturnValue

Name Description
Struct

extractSignature

fun Struct.extractSignature(): Signature

Extracts this Struct indicator and converts it to Signature

Receiver

Name Description
Struct

ReturnValue

Name Description
Signature

evalAsExpression

fun Term.evalAsExpression(request: Request<*>, index: Int?): Term

Receiver

Name Description
Term

Parameters

Name Description
request: Request<*>
index: Int?

ReturnValue

Name Description
Term

evalAsArithmeticExpression

fun Term.evalAsArithmeticExpression(request: Request<*>, index: Int?): Numeric

Receiver

Name Description
Term

Parameters

Name Description
request: Request<*>
index: Int?

ReturnValue

Name Description
Numeric

eq

infix fun Term.eq(that: Term): Equation

Creates an equation with this and that terms

Receiver

Name Description
Term

Parameters

Name Description
that: Term

ReturnValue

Name Description
Equation

CompanionObject

Rule

interface Rule: Clause, Any

Fields

Name Description
const FUNCTOR: String

Methods

of

fun of(head: Struct, vararg body: Term): Rule

Parameters

Name Description
head: Struct
vararg body: Term

ReturnValue

Name Description
Rule

of

fun of(head: Struct, body: Iterable<Term>): Rule

Parameters

Name Description
head: Struct
body: Iterable<Term>

ReturnValue

Name Description
Rule

of

fun of(head: Struct, body: Sequence<Term>): Rule

Parameters

Name Description
head: Struct
body: Sequence<Term>

ReturnValue

Name Description
Rule

template

fun template(functor: String, arity: Int): Rule

Parameters

Name Description
functor: String
arity: Int

ReturnValue

Name Description
Rule