io.github.prolobjectlink.prolog

Interface PrologStructure

All Superinterfaces:

Comparable<PrologTerm>, PrologElement, PrologTerm

All Known Implementing Classes:

PrologBuiltin

public interface PrologStructure
extends PrologTerm

Represent structured prolog compound term. Prolog structures consist in a relation the functor (structure name) and arguments enclosed between parenthesis.

The Prolog Provider is the mechanism to create a new Prolog structures invoking PrologProvider.newStructure(String, PrologTerm...).

Two structures are equals if and only if are structure and have equals functor and arguments. Structures terms unify only with same functor and arguments structures, with free variable or with with structures where your arguments unify if they have the same functor and arity.

Structures have a special property named arity that means the number of arguments present in the structure.

There are two special structures term. They are expressions (Two arguments structure term with operator functor) and atoms (functor with zero arguments). For the first special case must be used PrologProvider.newStructure(PrologTerm, String, PrologTerm) specifying operands like arguments and operator like functor. For the second special case must be used PrologProvider.newAtom(String) specifying functor only.

Since:

1.0

Author:

Jose Zalacain

Method Summary

Modifier and Type	Method and Description
PrologTerm	getLeft() Return the left operand of the current term if the current term is an evalueble structure (expression).
String	getOperator() Return the operator (structure functor) of the current term if the current term is an evalueble structure (expression).
PrologTerm	getRight() Return the right operand of the current term if the current term is an evalueble structure (expression).

Methods inherited from interface io.github.prolobjectlink.prolog.PrologTerm

cast, getArgument, getArguments, getArity, getFunctor, getIndicator, getObject, getProvider, getTerm, getType, hasIndicator, isAtom, isAtomic, isClass, isCompound, isDouble, isEmptyList, isEntry, isEvaluable, isFalseType, isField, isFloat, isInteger, isList, isLong, isMap, isMixin, isNil, isNullType, isNumber, isObjectType, isParameter, isReference, isResult, isStructure, isTrueType, isVariable, isVariableBound, isVariableNotBound, isVoidType, match, unify

Methods inherited from interface java.lang.Comparable

compareTo

Methods inherited from interface io.github.prolobjectlink.prolog.PrologElement

isClause, isTerm

Method Detail

getOperator

String getOperator()

Return the operator (structure functor) of the current term if the current term is an evalueble structure (expression). This method is equivalent to invoke #PrologTerm.getFunctor()

Returns:

return the operator of the current term if the current term is an (expression).

Since:

1.0

getLeft

PrologTerm getLeft()

Return the left operand of the current term if the current term is an evalueble structure (expression). This method is equivalent to invoke PrologTerm.getArgument(int) with integer parameter equals to zero.

Returns:

return the left operand of the current term if the current term is an expression.

Since:

1.0

getRight

PrologTerm getRight()

Return the right operand of the current term if the current term is an evalueble structure (expression). This method is equivalent to invoke PrologTerm.getArgument(int) with integer parameter equals to one.

Returns:

return the right operand of the current term if the current term is an expression.

Since:

1.0