polyglot.util
Class CollectionUtil

java.lang.Object
  polyglot.util.CollectionUtil

public class CollectionUtil
extends java.lang.Object

Collection utilities.

Constructor Summary

CollectionUtil()

Method Summary

static java.util.List	add(java.util.List l, java.lang.Object o) Append o to l, returning l.
static boolean	equals(java.util.Collection a, java.util.Collection b) Return true if a and b are pointer equal, or if iterators over both return the same sequence of pointer equal elements.
static java.lang.Object	firstOrElse(java.util.Collection l, java.lang.Object alt)
static java.util.List	list() Return an empty list.
static java.util.List	list(java.lang.Object o) Return a singleton list containing o.
static java.util.List	list(java.lang.Object o1, java.lang.Object o2) Return a list containing o1 and o2.
static java.util.List	list(java.lang.Object o1, java.lang.Object o2, java.lang.Object o3) Return a list containing o1, ..., o3.
static java.util.List	list(java.lang.Object o1, java.lang.Object o2, java.lang.Object o3, java.lang.Object o4) Return a list containing o1, ..., o4.
static java.util.List	map(java.util.List l, Transformation t) Apply t to each element of l.
static java.util.List	nonNullList(java.util.List l) Return an empty non-null list if the argument list is null.
static java.util.Iterator	pairs(java.util.Collection l)

Methods inherited from class java.lang.Object

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

Constructor Detail

CollectionUtil

public CollectionUtil()

Method Detail

add

public static java.util.List add(java.util.List l,
                                 java.lang.Object o)

Append o to l, returning l.

equals

public static boolean equals(java.util.Collection a,
                             java.util.Collection b)

Return true if a and b are pointer equal, or if iterators over both return the same sequence of pointer equal elements.

list

public static java.util.List list()

Return an empty list.

list

public static java.util.List list(java.lang.Object o)

Return a singleton list containing o.

list

public static java.util.List list(java.lang.Object o1,
                                  java.lang.Object o2)

Return a list containing o1 and o2.

list

public static java.util.List list(java.lang.Object o1,
                                  java.lang.Object o2,
                                  java.lang.Object o3)

Return a list containing o1, ..., o3.

list

public static java.util.List list(java.lang.Object o1,
                                  java.lang.Object o2,
                                  java.lang.Object o3,
                                  java.lang.Object o4)

Return a list containing o1, ..., o4.

firstOrElse

public static java.lang.Object firstOrElse(java.util.Collection l,
                                           java.lang.Object alt)

pairs

public static java.util.Iterator pairs(java.util.Collection l)

map

public static java.util.List map(java.util.List l,
                                 Transformation t)

Apply t to each element of l. l is not modified.

Returns:

A list containing the result of each transformation, in the same order as the original elements.

nonNullList

public static java.util.List nonNullList(java.util.List l)

Return an empty non-null list if the argument list is null.

Parameters:

l - a possibly null list

Returns:

a non-null list