Class ListUtils

java.lang.Object

org.projog.core.term.ListUtils

public final class ListUtils
extends Object

Helper methods for performing common tasks with Prolog list data structures.

See Also:

• List
• ListFactory
• TermUtils

Method Summary

Modifier and Type	Method	Description
static boolean	isMember(Term element, Term list)	Checks is a term can be unified with at least one element of a list.
static List<Term>	toJavaUtilList(Term list)	Returns a new java.util.List containing the contents of the specified org.projog.core.term.List.
static List<Term>	toSortedJavaUtilList(Term unsorted)	Returns a new java.util.List containing the sorted contents of the specified org.projog.core.term.List.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

toJavaUtilList

public static List<Term> toJavaUtilList(Term list)

Returns a new java.util.List containing the contents of the specified org.projog.core.term.List.

Will return null if list is neither of type TermType.LIST or TermType.EMPTY_LIST, or if list represents a partial list (i.e. a list that does not have an empty list as its tail).

See Also:

• toSortedJavaUtilList(Term)

toSortedJavaUtilList

public static List<Term> toSortedJavaUtilList(Term unsorted)

Returns a new java.util.List containing the sorted contents of the specified org.projog.core.term.List.

The elements in the returned list will be ordered using the standard ordering of terms, as implemented by TermComparator.

Will return null if list is neither of type TermType.LIST or TermType.EMPTY_LIST, or if list represents a partial list (i.e. a list that does not have an empty list as its tail).

See Also:

• toJavaUtilList(Term)

isMember

public static boolean isMember(Term element,
 Term list)

Checks is a term can be unified with at least one element of a list.

Iterates through each element of list attempting to unify with element. Returns true immediately after the first unifiable element is found. If list contains no elements that can be unified with element then false is returned.

Throws:

ProjogException - if list is not of type TermType#LIST or TermType#EMPTY_LIST