Var

interface Var: Term, Any

Fields

Name Description
open isVariable: Boolean

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

open variables: Sequence<Var>

The sequence of Variables directly or indirectly contained in the current term. Variables are lazily returned in a non-deterministic order. Notice that no occurrence-check is performed. Thus, if a Term contains the same Variable twice or more times, then the variables sequence may contain as many occurrences of that Variable

open isAnonymous: Boolean
abstract name: String
abstract completeName: String
abstract isNameWellFormed: Boolean

Methods

freshCopy

open fun freshCopy(): Var

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
Var

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

freshCopy

open fun freshCopy(scope: Scope): Var

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
Var

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

Extensions

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

eq

infix fun Term.eq(that: Term): Equation<Term, Term>

Creates an equation with this and that terms

Receiver

Name Description
Term

Parameters

Name Description
that: Term

ReturnValue

Name Description
Equation<Term, Term>

CompanionObject

Var

interface Var: Term, Any

Fields

Name Description
const ANONYMOUS_VAR_NAME: String
val VAR_REGEX_PATTERN: "[A-Z_][A-Za-z_0-9]*".toRegex()

Methods

of

fun of(name: String): Var

Parameters

Name Description
name: String

ReturnValue

Name Description
Var

anonymous

fun anonymous(): Var

ReturnValue

Name Description
Var

escapeName

fun escapeName(string: String): String

Parameters

Name Description
string: String

ReturnValue

Name Description
String

escapeNameIfNecessary

fun escapeNameIfNecessary(string: String): String

Parameters

Name Description
string: String

ReturnValue

Name Description
String