| Current File : //opt/alt/libicu/usr/include/unicode/ucoleitr.h |
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 2001-2014, International Business Machines
* Corporation and others. All Rights Reserved.
*******************************************************************************
*
* File ucoleitr.h
*
* Modification History:
*
* Date Name Description
* 02/15/2001 synwee Modified all methods to process its own function
* instead of calling the equivalent c++ api (coleitr.h)
*******************************************************************************/
#ifndef UCOLEITR_H
#define UCOLEITR_H
#include "unicode/utypes.h"
#if !UCONFIG_NO_COLLATION
/**
* This indicates an error has occured during processing or if no more CEs is
* to be returned.
* @stable ICU 2.0
*/
#define UCOL_NULLORDER ((int32_t)0xFFFFFFFF)
#include "unicode/ucol.h"
/**
* The UCollationElements struct.
* For usage in C programs.
* @stable ICU 2.0
*/
typedef struct UCollationElements UCollationElements;
/**
* \file
* \brief C API: UCollationElements
*
* The UCollationElements API is used as an iterator to walk through each
* character of an international string. Use the iterator to return the
* ordering priority of the positioned character. The ordering priority of a
* character, which we refer to as a key, defines how a character is collated
* in the given collation object.
* For example, consider the following in Slovak and in traditional Spanish collation:
* <pre>
* . "ca" -> the first key is key('c') and second key is key('a').
* . "cha" -> the first key is key('ch') and second key is key('a').
* </pre>
* And in German phonebook collation,
* <pre>
* . "<ae ligature>b"-> the first key is key('a'), the second key is key('e'), and
* . the third key is key('b').
* </pre>
* <p>Example of the iterator usage: (without error checking)
* <pre>
* . void CollationElementIterator_Example()
* . {
* . UChar *s;
* . t_int32 order, primaryOrder;
* . UCollationElements *c;
* . UCollatorOld *coll;
* . UErrorCode success = U_ZERO_ERROR;
* . s=(UChar*)malloc(sizeof(UChar) * (strlen("This is a test")+1) );
* . u_uastrcpy(s, "This is a test");
* . coll = ucol_open(NULL, &success);
* . c = ucol_openElements(coll, str, u_strlen(str), &status);
* . order = ucol_next(c, &success);
* . ucol_reset(c);
* . order = ucol_prev(c, &success);
* . free(s);
* . ucol_close(coll);
* . ucol_closeElements(c);
* . }
* </pre>
* <p>
* ucol_next() returns the collation order of the next.
* ucol_prev() returns the collation order of the previous character.
* The Collation Element Iterator moves only in one direction between calls to
* ucol_reset. That is, ucol_next() and ucol_prev can not be inter-used.
* Whenever ucol_prev is to be called after ucol_next() or vice versa,
* ucol_reset has to be called first to reset the status, shifting pointers to
* either the end or the start of the string. Hence at the next call of
* ucol_prev or ucol_next, the first or last collation order will be returned.
* If a change of direction is done without a ucol_reset, the result is
* undefined.
* The result of a forward iterate (ucol_next) and reversed result of the
* backward iterate (ucol_prev) on the same string are equivalent, if
* collation orders with the value 0 are ignored.
* Character based on the comparison level of the collator. A collation order
* consists of primary order, secondary order and tertiary order. The data
* type of the collation order is <strong>int32_t</strong>.
*
* @see UCollator
*/
/**
* Open the collation elements for a string.
*
* @param coll The collator containing the desired collation rules.
* @param text The text to iterate over.
* @param textLength The number of characters in text, or -1 if null-terminated
* @param status A pointer to a UErrorCode to receive any errors.
* @return a struct containing collation element information
* @stable ICU 2.0
*/
U_STABLE UCollationElements* U_EXPORT2
ucol_openElements(const UCollator *coll,
const UChar *text,
int32_t textLength,
UErrorCode *status);
/**
* get a hash code for a key... Not very useful!
* @param key the given key.
* @param length the size of the key array.
* @return the hash code.
* @stable ICU 2.0
*/
U_STABLE int32_t U_EXPORT2
ucol_keyHashCode(const uint8_t* key, int32_t length);
/**
* Close a UCollationElements.
* Once closed, a UCollationElements may no longer be used.
* @param elems The UCollationElements to close.
* @stable ICU 2.0
*/
U_STABLE void U_EXPORT2
ucol_closeElements(UCollationElements *elems);
/**
* Reset the collation elements to their initial state.
* This will move the 'cursor' to the beginning of the text.
* Property settings for collation will be reset to the current status.
* @param elems The UCollationElements to reset.
* @see ucol_next
* @see ucol_previous
* @stable ICU 2.0
*/
U_STABLE void U_EXPORT2
ucol_reset(UCollationElements *elems);
/**
* Get the ordering priority of the next collation element in the text.
* A single character may contain more than one collation element.
* @param elems The UCollationElements containing the text.
* @param status A pointer to a UErrorCode to receive any errors.
* @return The next collation elements ordering, otherwise returns UCOL_NULLORDER
* if an error has occured or if the end of string has been reached
* @stable ICU 2.0
*/
U_STABLE int32_t U_EXPORT2
ucol_next(UCollationElements *elems, UErrorCode *status);
/**
* Get the ordering priority of the previous collation element in the text.
* A single character may contain more than one collation element.
* Note that internally a stack is used to store buffered collation elements.
* @param elems The UCollationElements containing the text.
* @param status A pointer to a UErrorCode to receive any errors. Noteably
* a U_BUFFER_OVERFLOW_ERROR is returned if the internal stack
* buffer has been exhausted.
* @return The previous collation elements ordering, otherwise returns
* UCOL_NULLORDER if an error has occured or if the start of string has
* been reached.
* @stable ICU 2.0
*/
U_STABLE int32_t U_EXPORT2
ucol_previous(UCollationElements *elems, UErrorCode *status);
/**
* Get the maximum length of any expansion sequences that end with the
* specified comparison order.
* This is useful for .... ?
* @param elems The UCollationElements containing the text.
* @param order A collation order returned by previous or next.
* @return maximum size of the expansion sequences ending with the collation
* element or 1 if collation element does not occur at the end of any
* expansion sequence
* @stable ICU 2.0
*/
U_STABLE int32_t U_EXPORT2
ucol_getMaxExpansion(const UCollationElements *elems, int32_t order);
/**
* Set the text containing the collation elements.
* Property settings for collation will remain the same.
* In order to reset the iterator to the current collation property settings,
* the API reset() has to be called.
* @param elems The UCollationElements to set.
* @param text The source text containing the collation elements.
* @param textLength The length of text, or -1 if null-terminated.
* @param status A pointer to a UErrorCode to receive any errors.
* @see ucol_getText
* @stable ICU 2.0
*/
U_STABLE void U_EXPORT2
ucol_setText( UCollationElements *elems,
const UChar *text,
int32_t textLength,
UErrorCode *status);
/**
* Get the offset of the current source character.
* This is an offset into the text of the character containing the current
* collation elements.
* @param elems The UCollationElements to query.
* @return The offset of the current source character.
* @see ucol_setOffset
* @stable ICU 2.0
*/
U_STABLE int32_t U_EXPORT2
ucol_getOffset(const UCollationElements *elems);
/**
* Set the offset of the current source character.
* This is an offset into the text of the character to be processed.
* Property settings for collation will remain the same.
* In order to reset the iterator to the current collation property settings,
* the API reset() has to be called.
* @param elems The UCollationElements to set.
* @param offset The desired character offset.
* @param status A pointer to a UErrorCode to receive any errors.
* @see ucol_getOffset
* @stable ICU 2.0
*/
U_STABLE void U_EXPORT2
ucol_setOffset(UCollationElements *elems,
int32_t offset,
UErrorCode *status);
/**
* Get the primary order of a collation order.
* @param order the collation order
* @return the primary order of a collation order.
* @stable ICU 2.6
*/
U_STABLE int32_t U_EXPORT2
ucol_primaryOrder (int32_t order);
/**
* Get the secondary order of a collation order.
* @param order the collation order
* @return the secondary order of a collation order.
* @stable ICU 2.6
*/
U_STABLE int32_t U_EXPORT2
ucol_secondaryOrder (int32_t order);
/**
* Get the tertiary order of a collation order.
* @param order the collation order
* @return the tertiary order of a collation order.
* @stable ICU 2.6
*/
U_STABLE int32_t U_EXPORT2
ucol_tertiaryOrder (int32_t order);
#endif /* #if !UCONFIG_NO_COLLATION */
#endif