The Ucollator module performs locale-sensitive string comparison.

Required Header

#include <utils_i18n.h>

Overview

The Ucollator module performs locale-sensitive string comparison. It builds searching and sorting routines for natural language text and provides correct sorting orders for most locales supported.

Sample Code 1

Converts two different byte strings to two different unicode strings and compares the unicode strings to check if the strings are equal to each other.

    i18n_uchar uchar_src[64] = {0,};
    i18n_uchar uchar_target[64] = {0,};
    char *src = "tizen";
    char *target = "bada";
    int uchar_src_len = 0;
    int uchar_target_len = 0;
    i18n_ucollator_h coll = NULL;
    i18n_ubool result = NULL;

    i18n_ustring_from_UTF8( uchar_src, 64, NULL, src, -1 );
    i18n_ustring_from_UTF8( uchar_target, 64, NULL, target, -1 );

    // creates a collator
    i18n_ucollator_create( "en_US", &coll );

    // sets strength for coll
    i18n_ucollator_set_strength( coll, I18N_UCOLLATOR_PRIMARY );

    // compares uchar_src with uchar_target
    i18n_ustring_get_length( uchar_src, &uchar_src_len );
    i18n_ustring_get_length( uchar_target, &uchar_target_len );
    i18n_ucollator_equal( coll, uchar_src, uchar_src_len, uchar_target, uchar_target_len, &result );
    dlog_print(DLOG_INFO, LOG_TAG, "%s %s %s\n", src, result == 1 ? "is equal to" : "is not equal to", target );    // tizen is not equal to bada

    // destroys the collator
    i18n_ucollator_destroy( coll );

Sample Code 2

Sorts in ascending order on the given data using string_ucollator

    i18n_ucollator_h coll = NULL;
    char *src[3] = { "cat", "banana", "airplane" };
    char *tmp = NULL;
    i18n_uchar buf_01[16] = {0,};
    i18n_uchar buf_02[16] = {0,};
    i18n_ucollator_result_e result = I18N_UCOLLATOR_EQUAL;
    int i = 0, j = 0;
    int ret = I18N_ERROR_NONE;
    int buf_01_len = 0, buf_02_len = 0;

    for (i = 0; i < sizeof(src) / sizeof(src[0]); i++) {
        dlog_print(DLOG_INFO, LOG_TAG, "%s\n", src[i]);
    }    // cat    banana    airplane

    // creates a collator
    ret = i18n_ucollator_create("en_US", &coll);

    // compares and sorts in ascending order
    if (ret == I18N_ERROR_NONE) {
        i18n_ucollator_set_strength(coll, I18N_UCOLLATOR_TERTIARY);
        for (i = 0; i < 2; i++) {
            for (j = 0; j < 2 - i; j++) {
                i18n_ustring_copy_ua(buf_01, src[j]);
                i18n_ustring_copy_ua(buf_02, src[j+1]);
                i18n_ustring_get_length(buf_01, &buf_01_len);
                i18n_ustring_get_length(buf_02, &buf_02_len);
                // compares buf_01 with buf_02
                i18n_ucollator_str_collator(coll, buf_01, buf_01_len, buf_02, buf_02_len, &result);
                if (result == I18N_UCOLLATOR_GREATER) {
                    tmp = src[j];
                    src[j] = src[j+1];
                    src[j+1] = tmp;
                }
            }
        }
    }
    // destroys the collator
    i18n_ucollator_destroy( coll );    // deallocate memory for collator

    for (i = 0; i < sizeof(src) / sizeof(src[0]); i++) {
        dlog_print(DLOG_INFO, LOG_TAG, "%s\n", src[i]);
    }    // ariplane    banana    cat

Functions
int	i18n_ucollator_create (const char locale, i18n_ucollator_h collator)
	Creates a i18n_ucollator_h for comparing strings.
int	i18n_ucollator_destroy (i18n_ucollator_h collator)
	Closes a i18n_ucollator_h.
int	i18n_ucollator_str_collator (const i18n_ucollator_h collator, const i18n_uchar src, int32_t src_len, const i18n_uchar target, int32_t target_len, i18n_ucollator_result_e *result)
	Compares two strings.
int	i18n_ucollator_equal (const i18n_ucollator_h collator, const i18n_uchar src, int32_t src_len, const i18n_uchar target, int32_t target_len, i18n_ubool *equal)
	Compares two strings for equality.
int	i18n_ucollator_set_strength (i18n_ucollator_h collator, i18n_ucollator_strength_e strength)
	Sets the collation strength used in a collator.
int	i18n_ucollator_set_attribute (i18n_ucollator_h collator, i18n_ucollator_attribute_e attr, i18n_ucollator_attribute_value_e val)
	Sets a universal attribute setter.
Typedefs
typedef void *	i18n_ucollator_h
	Structure representing a collator object instance.
typedef i18n_ucollator_attribute_value_e	i18n_ucollator_strength_e
	Enumeration in which the base letter represents a primary difference. Set comparison level to I18N_UCOLLATOR_PRIMARY to ignore secondary and tertiary differences. Use this to set the strength of an i18n_ucollator_h. Example of primary difference, "abc" < "abd" Diacritical differences on the same base letter represent a secondary difference. Set comparison level to I18N_UCOLLATOR_SECONDARY to ignore tertiary differences. Use this to set the strength of an i18n_ucollator_h. Example of secondary difference, "ä" >> "a". Uppercase and lowercase versions of the same character represent a tertiary difference. Set comparison level to I18N_UCOLLATOR_TERTIARY to include all comparison differences. Use this to set the strength of an i18n_ucollator_h. Example of tertiary difference, "abc" <<< "ABC". Two characters are considered "identical" when they have the same unicode spellings. I18N_UCOLLATOR_IDENTICAL. For example, "ä" == "ä". i18n_ucollator_strength_e is also used to determine the strength of sort keys generated from i18n_ucollator_h. These values can now be found in the i18n_ucollator_attribute_value_e enum.

Typedef Documentation

typedef void* i18n_ucollator_h

Structure representing a collator object instance.

Since :: 2.3

typedef i18n_ucollator_attribute_value_e i18n_ucollator_strength_e

Enumeration in which the base letter represents a primary difference. Set comparison level to I18N_UCOLLATOR_PRIMARY to ignore secondary and tertiary differences. Use this to set the strength of an i18n_ucollator_h. Example of primary difference, "abc" < "abd" Diacritical differences on the same base letter represent a secondary difference. Set comparison level to I18N_UCOLLATOR_SECONDARY to ignore tertiary differences. Use this to set the strength of an i18n_ucollator_h. Example of secondary difference, "ä" >> "a". Uppercase and lowercase versions of the same character represent a tertiary difference. Set comparison level to I18N_UCOLLATOR_TERTIARY to include all comparison differences. Use this to set the strength of an i18n_ucollator_h. Example of tertiary difference, "abc" <<< "ABC". Two characters are considered "identical" when they have the same unicode spellings. I18N_UCOLLATOR_IDENTICAL. For example, "ä" == "ä". i18n_ucollator_strength_e is also used to determine the strength of sort keys generated from i18n_ucollator_h. These values can now be found in the i18n_ucollator_attribute_value_e enum.

Since :: 2.3

Enumeration Type Documentation

enum i18n_ucollator_attribute_e

Enumeration for attributes that collation service understands. All the attributes can take I18N_UCOLLATOR_DEFAULT value, as well as the values specific to each one.

Since :: 2.3

Enumerator:

I18N_UCOLLATOR_FRENCH_COLLATION	Attribute for direction of secondary weights - used in Canadian French. Acceptable values are I18N_UCOLLATOR_ON, which results in secondary weights being considered backwards, and I18N_UCOLLATOR_OFF which treats secondary weights in the order they appear
I18N_UCOLLATOR_ALTERNATE_HANDLING	Attribute for handling variable elements. Acceptable values are I18N_UCOLLATOR_NON_IGNORABLE (default) which treats all the codepoints with non-ignorable primary weights in the same way, and I18N_UCOLLATOR_SHIFTED which causes codepoints with primary weights that are equal or below the variable top value to be ignored at the primary level and moved to the quaternary level
I18N_UCOLLATOR_CASE_FIRST	Controls the ordering of upper and lower case letters. Acceptable values are I18N_UCOLLATOR_OFF (default), which orders upper and lower case letters in accordance to their tertiary weights, I18N_UCOLLATOR_UPPER_FIRST which forces upper case letters to sort before lower case letters, and I18N_UCOLLATOR_LOWER_FIRST which does the opposite
I18N_UCOLLATOR_CASE_LEVEL	Controls whether an extra case level (positioned before the third level) is generated or not. Acceptable values are I18N_UCOLLATOR_OFF (default), when case level is not generated, and I18N_UCOLLATOR_ON which causes the case level to be generated. Contents of the case level are affected by the value of the I18N_UCOLLATOR_CASE_FIRST attribute. A simple way to ignore accent differences in a string is to set the strength to I18N_UCOLLATOR_PRIMARY and enable case level
I18N_UCOLLATOR_NORMALIZATION_MODE	Controls whether the normalization check and necessary normalizations are performed. When set to I18N_UCOLLATOR_OFF (default) no normalization check is performed. The correctness of the result is guaranteed only if the input data is in so-called FCD form (see users manual for more info). When set to I18N_UCOLLATOR_ON, an incremental check is performed to see whether the input data is in the FCD form. If the data is not in the FCD form, incremental NFD normalization is performed
I18N_UCOLLATOR_DECOMPOSITION_MODE	An alias for the I18N_UCOLLATOR_NORMALIZATION_MODE attribute
I18N_UCOLLATOR_STRENGTH	The strength attribute. Can be either I18N_UCOLLATOR_PRIMARY, I18N_UCOLLATOR_SECONDARY, I18N_UCOLLATOR_TERTIARY, I18N_UCOLLATOR_QUATERNARY, or I18N_UCOLLATOR_IDENTICAL. The usual strength for most locales (except Japanese) is tertiary. Quaternary strength is useful when combined with shifted setting for the alternate handling attribute and for JIS X 4061 collation, when it is used to distinguish between Katakana and Hiragana. Otherwise, quaternary level is affected only by the number of non-ignorable code points in the string. Identical strength is rarely useful, as it amounts to codepoints of the NFD form of the string
I18N_UCOLLATOR_NUMERIC_COLLATION	When turned on, this attribute makes substrings of digits that are sort according to their numeric values. This is a way to get '100' to sort AFTER '2'. Note that the longest digit substring that can be treated as a single unit is 254 digits (not counting leading zeros). If a digit substring is longer than that, the digits beyond the limit will be treated as a separate digit substring. A "digit" in this sense is a code point with General_Category=Nd, which does not include circled numbers, roman numerals, and so on. Only a contiguous digit substring is considered, that is, non-negative integers without separators. There is no support for plus/minus signs, decimals, exponents, and so on
I18N_UCOLLATOR_ATTRIBUTE_COUNT	The number of i18n_ucollator_attribute_e constants

enum i18n_ucollator_attribute_value_e

Enumeration containing attribute values for controlling collation behavior. Here are all the allowable values. Not every attribute can take every value. The only universal value is I18N_UCOLLATOR_DEFAULT, which resets the attribute value to the predefined value for that locale.

Since :: 2.3

Enumerator:

I18N_UCOLLATOR_DEFAULT	Accepted by most attributes
I18N_UCOLLATOR_PRIMARY	Primary collation strength
I18N_UCOLLATOR_SECONDARY	Secondary collation strength
I18N_UCOLLATOR_TERTIARY	Tertiary collation strength
I18N_UCOLLATOR_DEFAULT_STRENGTH	Default collation strength
I18N_UCOLLATOR_QUATERNARY	Quaternary collation strength
I18N_UCOLLATOR_IDENTICAL	Identical collation strength
I18N_UCOLLATOR_OFF	Turn the feature off - works for I18N_UCOLLATOR_FRENCH_COLLATION, I18N_UCOLLATOR_CASE_LEVEL & I18N_UCOLLATOR_DECOMPOSITION_MODE
I18N_UCOLLATOR_ON	Turn the feature on - works for I18N_UCOLLATOR_FRENCH_COLLATION, I18N_UCOLLATOR_CASE_LEVEL & I18N_UCOLLATOR_DECOMPOSITION_MODE
I18N_UCOLLATOR_SHIFTED	Valid for I18N_UCOLLATOR_ALTERNATE_HANDLING. Alternate handling will be shifted.
I18N_UCOLLATOR_NON_IGNORABLE	Valid for I18N_UCOLLATOR_ALTERNATE_HANDLING. Alternate handling will be non ignorable.
I18N_UCOLLATOR_LOWER_FIRST	Valid for I18N_UCOLLATOR_CASE_FIRST - lower case sorts before upper case.
I18N_UCOLLATOR_UPPER_FIRST	Upper case sorts before lower case.

enum i18n_ucollator_result_e

Enumeration for source and target string comparison result. I18N_UCOLLATOR_LESS is returned if the source string is compared to be less than the target string in the i18n_ucollator_str_collator() method. I18N_UCOLLATOR_EQUAL is returned if the source string is compared to be equal to the target string in the i18n_ucollator_str_collator() method. I18N_UCOLLATOR_GREATER is returned if the source string is compared to be greater than the target string in the i18n_ucollator_str_collator() method.

Since :: 2.3

Enumerator:

I18N_UCOLLATOR_EQUAL	string a == string b
I18N_UCOLLATOR_GREATER	string a > string b
I18N_UCOLLATOR_LESS	string a < string b

Function Documentation

int i18n_ucollator_create	(	const char *	locale,
		i18n_ucollator_h *	collator
	)

Creates a i18n_ucollator_h for comparing strings.

For some languages, multiple collation types are available; for example, "de@collation=phonebook". Collation attributes can be specified via locale keywords as well, in the old locale extension syntax ("el@colCaseFirst=upper") or in language tag syntax ("el-u-kf-upper"). See User Guide: Collation API.

The i18n_ucollator_h is used in all the calls to the Collation service.
After finished, collator must be disposed off by calling i18n_ucollator_destroy().

Since :: 2.3

Remarks:: Must release collator using i18n_ucollator_destroy().

Parameters:

[in]	locale	The locale containing the required collation rules Special values for locales can be passed in - if `NULL` is passed for the locale, the default locale collation rules will be used If empty string ("") or "root" is passed, UCA rules will be used.
[out]	collator	i18n_ucollator_h, otherwise `0` if an error occurs

Return values:

I18N_ERROR_NONE	Successful
I18N_ERROR_INVALID_PARAMETER	Invalid function parameter

See also:: i18n_ucollator_destroy()

int i18n_ucollator_destroy ( i18n_ucollator_h collator )

Closes a i18n_ucollator_h.

Once closed, a string_ucollator_h should not be used. Every an open collator should be closed. Otherwise, a memory leak will result.

Since :: 2.3

Parameters:

[in] collator The i18n_ucollator_h to close

Return values:

I18N_ERROR_NONE	Successful
I18N_ERROR_INVALID_PARAMETER	Invalid function parameter

See also:: i18n_ucollator_create()

int i18n_ucollator_equal	(	const i18n_ucollator_h	collator,
		const i18n_uchar *	src,
		int32_t	src_len,
		const i18n_uchar *	target,
		int32_t	target_len,
		i18n_ubool *	equal
	)

Compares two strings for equality.

This function is equivalent to i18n_ucollator_str_collator().

Since :: 2.3

Parameters:

[in]	collator	The i18n_ucollator_h containing the comparison rules
[in]	src	The source string
[in]	src_len	The length of the source, otherwise `-1` if null-terminated
[in]	target	The target string
[in]	target_len	The length of the target, otherwise `-1` if null-terminated
[out]	equal	If `true` source is equal to target, otherwise `false`

Return values:

I18N_ERROR_NONE	Successful
I18N_ERROR_INVALID_PARAMETER	Invalid function parameter

See also:: i18n_ucollator_str_collator()

int i18n_ucollator_set_attribute	(	i18n_ucollator_h	collator,
		i18n_ucollator_attribute_e	attr,
		i18n_ucollator_attribute_value_e	val
	)

Sets a universal attribute setter.

Since :: 2.3

Parameters:

[in]	collator	The i18n_collator_h containing attributes to be changed
[in]	attr	The attribute type
[in]	val	The attribute value

Return values:

I18N_ERROR_NONE	Successful
I18N_ERROR_INVALID_PARAMETER	Invalid function parameter

int i18n_ucollator_set_strength	(	i18n_ucollator_h	collator,
		i18n_ucollator_strength_e	strength
	)

Sets the collation strength used in a collator.

The strength influences how strings are compared.

Since :: 2.3

Parameters:

[in]	collator	The i18n_collator_h to set.
[in]	strength	The desired collation strength. One of i18n_ucollator_strength_e

Return values:

I18N_ERROR_NONE	Successful
I18N_ERROR_INVALID_PARAMETER	Invalid function parameter

int i18n_ucollator_str_collator	(	const i18n_ucollator_h	collator,
		const i18n_uchar *	src,
		int32_t	src_len,
		const i18n_uchar *	target,
		int32_t	target_len,
		i18n_ucollator_result_e *	result
	)

Compares two strings.

The strings will be compared using the options already specified.

Since :: 2.3

Parameters:

[in]	collator	The i18n_ucollator_h containing the comparison rules
[in]	src	The source string
[in]	src_len	The length of the source, otherwise `-1` if null-terminated
[in]	target	The target string.
[in]	target_len	The length of the target, otherwise `-1` if null-terminated
[out]	result	The result of comparing the strings One of I18N_UCOLLATOR_EQUAL, I18N_UCOLLATOR_GREATER, or I18N_UCOLLATOR_LESS

Return values:

I18N_ERROR_NONE	Successful
I18N_ERROR_INVALID_PARAMETER	Invalid function parameter

See also:: i18n_ucollator_equal()

Required Header

Overview

Sample Code 1

Sample Code 2

Functions

Typedefs

Typedef Documentation

Enumeration Type Documentation

Function Documentation