UHashTable(3U)

NAME
UHashTable, UHashElem - hash table classes

SYNOPSIS
#include <Unidraw/uhash.h>

DESCRIPTION
UHashTable implements a simple open hash table. The number of slots can be specified when the table is created. UHashTable stores UHashElem instances, which contain the key that is hashed. Code that uses UHashTables may derive from UHashElem to store data in addition to the key. UHashTable also provides operations for iterating over the elements in the hash table.

UHASHELEM OPERATIONS

UHashElem(void* = nil)
    Create a UHashElem with the given key value.

void* GetKey()

void SetKey(void*)
    Explicitly get and set the element's key value.

UHASHTABLE PUBLIC OPERATIONS

UHashTable(int nslots)
    Create a new UHashTable, specifying its number of slots.

virtual void Register(void* key, UHashElem* = nil)
    Make an entry into the hash table. If no UHashElem is supplied, this function call the CreateElem function (described below) to create one, and it will call SetKey (with key as its argument) on the result.

virtual void Unregister(void* key)
    Remove the element with the matching key from the hash table and delete it.

void First(Iterator&)

void Next(Iterator&)

boolean Done(Iterator)

UHashElem* GetElem(Iterator)
    Operations for iterating over the elements in the hash table. These operation do not guarantee a particular ordering for the iteration. First initializes an iterator to point to the first element in the traversal, Next increments the iterator to point to the following element, and Done returns whether or not the iterator points beyond the last element in the traversal. GetElem returns the element to which the given iterator points.

UHashElem* Find(void* key)
    Find the element with the matching key (as defined by the Equal operation, described below) in the hash table.

UHASHTABLE PROTECTED OPERATIONS

virtual UHashElem* CreateElem()
    Return a new UHashElem instance. Subclasses of UHashTable should redefine this function if they use subclasses of UHashElem.

virtual int Hash(void* key)
    Hash the specified key to return a slot index. This value should be less than the value of the _nslots member variable.

virtual boolean Equal(void* key1, void* key2)
    Return whether the specified keys are equivalent. By default, Equal simply compares the pointers for equality. Subclasses may redefine this operation to make more sophisticated comparisons.

SEE ALSO
Iterator(3U)