RWUCollationKey

Module:  Internationalization Module   Group:  Unicode String Processing

Does Not Inherit

• Local Index
• Header File
• Description
• Example
• Related Classes
• Public Constructors
• Public Destructor
• Public Member Operators
• Public Member Functions

Members

getString() hash()

isValid() operator!=()

operator<() operator=()

operator==() RWUCollationKey()

#include <rw/i18n/RWUCollationKey.h> 

RWUCollationKey stores preprocessed comparison information for a Unicode string, and can be used to speed repeated string comparisons. For example, you might choose to use collation keys when sorting a set of strings.

To create a valid RWUCollationKey, call RWUCollator::getCollationKey(). Generating a key is a non-trivial operation, since it involves determining the collation elements and weights for an entire string. Comparing two RWUCollationKey objects, however, is fast.

---

NOTE -- Collation keys can only meaningfully be compared if they are created by the same collator, or by collators with the same attributes.

---

#include <rw/i18n/RWUCollationKey.h>
#include <rw/i18n/RWUCollator.h>
#include <rw/i18n/RWUConversionContext.h>
#include <rw/tvsrtvec.h>
#include <iostream>

using std::cout;
using std::endl;

int
main()
{
  // Indicate that source and target strings are
  // encoded as UTF-8.
  RWUConversionContext context("UTF-8");

  // Create an array of country names.
  RWUString array[] = {
    "United States",
    "Netherlands",
    "United Kingdom",
    "Germany",
    "France",
    "Italy",
    "Japan",
    "Australia",
    ""
  };
  size_t max_array_length = 20; 

  // Create a collator based on the "en" locale.
  RWUCollator collator("en");
  
  // Create an empty vector.  An RWTValSortedVector<T>
  // will automatically keep its contents in sorted 
  // order.
  RWTValSortedVector<RWUCollationKey,
                     std::less<RWUCollationKey> > vector(max_array_length);
  // Populate the vector with RWUCollationKey objects. 
  // Note that the vector will use
  // RWUCollationKey::operator<() and operator==().
  size_t i;
  for (i = 0; array[i].isNull() == false; ++i) {
    vector.insert(collator.getCollationKey(array[i]));
  } // for

  // Print the sorted vector.  Obtain RWUString objects
  // from the stored RWUCollationKey objects, implicitly
  // convert them to UTF-8, and print the UTF-8.
  cout << "Rogue Wave has offices in the following "
   "countries:" << endl;
  for (i = 0; i < vector.entries(); ++i) {
    cout << "  " << vector[i].getString() << endl;
  } // for

  return 0;
} // main

Results:
========

Rogue Wave has offices in the following countries:
  Australia
  France
  Germany
  Italy
  Japan
  Netherlands
  United Kingdom
  United States

RWUCollator

RWUCollationKey(void);

Default constructor. Creates an invalid key.

Invalid keys are equal to each other, and not equal to any other key. They are less than all other keys. Calling getString() on an invalid key results in an RWUException.

This constructor exists only as a convenience--for example, when creating an array of RWUCollationKey objects. To create a valid, usable RWUCollationKey, call RWUCollator::getCollationKey().

RWUCollationKey(const RWUCollationKey &original);

Copy constructor. Makes self a deep copy of original.

~RWUCollationKey(void);

Destructor.

RWUCollationKey&
operator=(const RWUCollationKey &rhs);

Assignment operator. Makes self a deep copy of rhs.

bool
operator==(const RWUCollationKey& rhs) const;

Returns true if self compares equal to collation key rhs; otherwise false.

Note that collation keys can only meaningfully be compared if they are created by the same collator, or by collators with the same attributes.

bool
operator!=(const RWUCollationKey& rhs) const;

Returns true if self does not compare equal to collation key rhs; otherwise false.

Note that collation keys can only meaningfully be compared if they are created by the same collator, or by collators with the same attributes.

bool
operator<(const RWUCollationKey& rhs) const;

Returns true if self compares less than collation key rhs; otherwise false.

Note that collation keys can only meaningfully be compared if they are created by the same collator, or by collators with the same attributes.

RWUString
getString(void) const;

Returns the string whose collation value self holds. Throws RWUException if self is an invalid key.

unsigned
hash() const;

Returns a hash value for self.

bool
isValid(void) const;

Returns true if self is a valid key; otherwise, false.

© Copyright Rogue Wave Software, Inc. All Rights Reserved.
Rogue Wave and SourcePro are registered trademarks of Rogue Wave Software, Inc. in the United States and other countries. All other trademarks are the property of their respective owners.
Contact Rogue Wave about documentation or support issues.