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ucol.h (68969B)

---

// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (c) 1996-2015, International Business Machines Corporation and others.
* All Rights Reserved.
*******************************************************************************
*/

#ifndef UCOL_H
#define UCOL_H

#include "unicode/utypes.h"

#if !UCONFIG_NO_COLLATION

#include "unicode/unorm.h"
#include "unicode/parseerr.h"
#include "unicode/uloc.h"
#include "unicode/uset.h"
#include "unicode/uscript.h"

#if U_SHOW_CPLUSPLUS_API
#include "unicode/localpointer.h"
#endif   // U_SHOW_CPLUSPLUS_API

/**
* \file
* \brief C API: Collator 
*
* <h2> Collator C API </h2>
*
* The C API for Collator performs locale-sensitive
* string comparison. You use this service to build
* searching and sorting routines for natural language text.
* <p>
* For more information about the collation service see 
* <a href="https://unicode-org.github.io/icu/userguide/collation">the User Guide</a>.
* <p>
* Collation service provides correct sorting orders for most locales supported in ICU. 
* If specific data for a locale is not available, the orders eventually falls back
* to the <a href="http://www.unicode.org/reports/tr35/tr35-collation.html#Root_Collation">CLDR root sort order</a>. 
* <p>
* Sort ordering may be customized by providing your own set of rules. For more on
* this subject see the <a href="https://unicode-org.github.io/icu/userguide/collation/customization">
* Collation Customization</a> section of the User Guide.
* <p>
* @see         UCollationResult
* @see         UNormalizationMode
* @see         UCollationStrength
* @see         UCollationElements
*/

/** A collator.
*  For usage in C programs.
*/
struct UCollator;
/** structure representing a collator object instance 
* @stable ICU 2.0
*/
typedef struct UCollator UCollator;


/**
* UCOL_LESS is returned if source string is compared to be less than target
* string in the ucol_strcoll() method.
* UCOL_EQUAL is returned if source string is compared to be equal to target
* string in the ucol_strcoll() method.
* UCOL_GREATER is returned if source string is compared to be greater than
* target string in the ucol_strcoll() method.
* @see ucol_strcoll()
* <p>
* Possible values for a comparison result 
* @stable ICU 2.0
*/
typedef enum {
 /** string a == string b */
 UCOL_EQUAL    = 0,
 /** string a > string b */
 UCOL_GREATER    = 1,
 /** string a < string b */
 UCOL_LESS    = -1
} UCollationResult ;


/** Enum 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 UCOL_DEFAULT, which resets the attribute value to the predefined  
* value for that locale 
* @stable ICU 2.0
*/
typedef enum {
 /** accepted by most attributes */
 UCOL_DEFAULT = -1,

 /** Primary collation strength */
 UCOL_PRIMARY = 0,
 /** Secondary collation strength */
 UCOL_SECONDARY = 1,
 /** Tertiary collation strength */
 UCOL_TERTIARY = 2,
 /** Default collation strength */
 UCOL_DEFAULT_STRENGTH = UCOL_TERTIARY,
 UCOL_CE_STRENGTH_LIMIT,
 /** Quaternary collation strength */
 UCOL_QUATERNARY=3,
 /** Identical collation strength */
 UCOL_IDENTICAL=15,
 UCOL_STRENGTH_LIMIT,

 /** Turn the feature off - works for UCOL_FRENCH_COLLATION, 
     UCOL_CASE_LEVEL, UCOL_HIRAGANA_QUATERNARY_MODE
     & UCOL_DECOMPOSITION_MODE*/
 UCOL_OFF = 16,
 /** Turn the feature on - works for UCOL_FRENCH_COLLATION, 
     UCOL_CASE_LEVEL, UCOL_HIRAGANA_QUATERNARY_MODE
     & UCOL_DECOMPOSITION_MODE*/
 UCOL_ON = 17,
 
 /** Valid for UCOL_ALTERNATE_HANDLING. Alternate handling will be shifted */
 UCOL_SHIFTED = 20,
 /** Valid for UCOL_ALTERNATE_HANDLING. Alternate handling will be non ignorable */
 UCOL_NON_IGNORABLE = 21,

 /** Valid for UCOL_CASE_FIRST - 
     lower case sorts before upper case */
 UCOL_LOWER_FIRST = 24,
 /** upper case sorts before lower case */
 UCOL_UPPER_FIRST = 25,

#ifndef U_HIDE_DEPRECATED_API
   /**
    * One more than the highest normal UColAttributeValue value.
    * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
    */
 UCOL_ATTRIBUTE_VALUE_COUNT
#endif  /* U_HIDE_DEPRECATED_API */
} UColAttributeValue;

/**
* Enum containing the codes for reordering segments of the collation table that are not script
* codes. These reordering codes are to be used in conjunction with the script codes.
* @see ucol_getReorderCodes
* @see ucol_setReorderCodes
* @see ucol_getEquivalentReorderCodes
* @see UScriptCode
* @stable ICU 4.8
*/
typedef enum {
  /**
   * A special reordering code that is used to specify the default
   * reordering codes for a locale.
   * @stable ICU 4.8
   */   
   UCOL_REORDER_CODE_DEFAULT       = -1,
  /**
   * A special reordering code that is used to specify no reordering codes.
   * @stable ICU 4.8
   */   
   UCOL_REORDER_CODE_NONE          = USCRIPT_UNKNOWN,
  /**
   * A special reordering code that is used to specify all other codes used for
   * reordering except for the codes lised as UColReorderCode values and those
   * listed explicitly in a reordering.
   * @stable ICU 4.8
   */   
   UCOL_REORDER_CODE_OTHERS        = USCRIPT_UNKNOWN,
  /**
   * Characters with the space property.
   * This is equivalent to the rule value "space".
   * @stable ICU 4.8
   */    
   UCOL_REORDER_CODE_SPACE         = 0x1000,
  /**
   * The first entry in the enumeration of reordering groups. This is intended for use in
   * range checking and enumeration of the reorder codes.
   * @stable ICU 4.8
   */    
   UCOL_REORDER_CODE_FIRST         = UCOL_REORDER_CODE_SPACE,
  /**
   * Characters with the punctuation property.
   * This is equivalent to the rule value "punct".
   * @stable ICU 4.8
   */    
   UCOL_REORDER_CODE_PUNCTUATION   = 0x1001,
  /**
   * Characters with the symbol property.
   * This is equivalent to the rule value "symbol".
   * @stable ICU 4.8
   */    
   UCOL_REORDER_CODE_SYMBOL        = 0x1002,
  /**
   * Characters with the currency property.
   * This is equivalent to the rule value "currency".
   * @stable ICU 4.8
   */    
   UCOL_REORDER_CODE_CURRENCY      = 0x1003,
  /**
   * Characters with the digit property.
   * This is equivalent to the rule value "digit".
   * @stable ICU 4.8
   */    
   UCOL_REORDER_CODE_DIGIT         = 0x1004,
#ifndef U_HIDE_DEPRECATED_API
   /**
    * One more than the highest normal UColReorderCode value.
    * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
    */
   UCOL_REORDER_CODE_LIMIT         = 0x1005
#endif  /* U_HIDE_DEPRECATED_API */
} UColReorderCode;

/**
* Base letter represents a primary difference.  Set comparison
* level to UCOL_PRIMARY to ignore secondary and tertiary differences.
* Use this to set the strength of a Collator object.
* Example of primary difference, "abc" &lt; "abd"
* 
* Diacritical differences on the same base letter represent a secondary
* difference.  Set comparison level to UCOL_SECONDARY to ignore tertiary
* differences. Use this to set the strength of a Collator object.
* Example of secondary difference, "&auml;" >> "a".
*
* Uppercase and lowercase versions of the same character represents a
* tertiary difference.  Set comparison level to UCOL_TERTIARY to include
* all comparison differences. Use this to set the strength of a Collator
* object.
* Example of tertiary difference, "abc" &lt;&lt;&lt; "ABC".
*
* Two characters are considered "identical" when they have the same
* unicode spellings.  UCOL_IDENTICAL.
* For example, "&auml;" == "&auml;".
*
* UCollationStrength is also used to determine the strength of sort keys 
* generated from UCollator objects
* These values can be now found in the UColAttributeValue enum.
* @stable ICU 2.0
**/
typedef UColAttributeValue UCollationStrength;

/** Attributes that collation service understands. All the attributes can take UCOL_DEFAULT
* value, as well as the values specific to each one. 
* @stable ICU 2.0
*/
typedef enum {
    /** Attribute for direction of secondary weights - used in Canadian French.
     * Acceptable values are UCOL_ON, which results in secondary weights
     * being considered backwards and UCOL_OFF which treats secondary
     * weights in the order they appear.
     * @stable ICU 2.0
     */
    UCOL_FRENCH_COLLATION, 
    /** Attribute for handling variable elements.
     * Acceptable values are UCOL_NON_IGNORABLE
     * which treats all the codepoints with non-ignorable
     * primary weights in the same way,
     * and UCOL_SHIFTED which causes codepoints with primary
     * weights that are equal or below the variable top value
     * to be ignored on primary level and moved to the quaternary
     * level. The default setting in a Collator object depends on the
     * locale data loaded from the resources. For most locales, the
     * default is UCOL_NON_IGNORABLE, but for others, such as "th",
     * the default could be UCOL_SHIFTED.
     * @stable ICU 2.0
     */
    UCOL_ALTERNATE_HANDLING,
    /** Controls the ordering of upper and lower case letters.
     * Acceptable values are UCOL_OFF, which orders
     * upper and lower case letters in accordance to their tertiary
     * weights, UCOL_UPPER_FIRST which forces upper case letters to
     * sort before lower case letters, and UCOL_LOWER_FIRST which does
     * the opposite. The default setting in a Collator object depends on the
     * locale data loaded from the resources. For most locales, the
     * default is UCOL_OFF, but for others, such as "da" or "mt",
     * the default could be UCOL_UPPER.
     * @stable ICU 2.0
     */
    UCOL_CASE_FIRST,
    /** Controls whether an extra case level (positioned before the third
     * level) is generated or not. Acceptable values are UCOL_OFF,
     * when case level is not generated, and UCOL_ON which causes the case
     * level to be generated. Contents of the case level are affected by
     * the value of UCOL_CASE_FIRST attribute. A simple way to ignore
     * accent differences in a string is to set the strength to UCOL_PRIMARY
     * and enable case level. The default setting in a Collator object depends
     * on the locale data loaded from the resources.
     * @stable ICU 2.0
     */
    UCOL_CASE_LEVEL,
    /** Controls whether the normalization check and necessary normalizations
     * are performed. When set to UCOL_OFF 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 UCOL_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. The default setting in a
     * Collator object depends on the locale data loaded from the resources.
     * For many locales, the default is UCOL_OFF, but for others, such as "hi"
     * "vi', or "bn", * the default could be UCOL_ON.
     * @stable ICU 2.0
     */
    UCOL_NORMALIZATION_MODE, 
    /** An alias for UCOL_NORMALIZATION_MODE attribute.
     * @stable ICU 2.0
     */
    UCOL_DECOMPOSITION_MODE = UCOL_NORMALIZATION_MODE,
    /** The strength attribute. Can be either UCOL_PRIMARY, UCOL_SECONDARY,
     * UCOL_TERTIARY, UCOL_QUATERNARY or UCOL_IDENTICAL. The usual strength
     * for most locales (except Japanese) is tertiary.
     *
     * Quaternary strength 
     * is useful when combined with shifted setting for 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.
     * @stable ICU 2.0
     */
    UCOL_STRENGTH,  
#ifndef U_HIDE_DEPRECATED_API
    /** When turned on, this attribute positions Hiragana before all  
     * non-ignorables on quaternary level This is a sneaky way to produce JIS
     * sort order.
     *
     * This attribute was an implementation detail of the CLDR Japanese tailoring.
     * Since ICU 50, this attribute is not settable any more via API functions.
     * Since CLDR 25/ICU 53, explicit quaternary relations are used
     * to achieve the same Japanese sort order.
     *
     * @deprecated ICU 50 Implementation detail, cannot be set via API, was removed from implementation.
     */
    UCOL_HIRAGANA_QUATERNARY_MODE = UCOL_STRENGTH + 1,
#endif  /* U_HIDE_DEPRECATED_API */
    /**
     * When turned on, this attribute makes
     * substrings of digits 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, etc.
     * Only a contiguous digit substring is considered, that is,
     * non-negative integers without separators.
     * There is no support for plus/minus signs, decimals, exponents, etc.
     *
     * @stable ICU 2.8
     */
    UCOL_NUMERIC_COLLATION = UCOL_STRENGTH + 2, 

   /* Do not conditionalize the following with #ifndef U_HIDE_DEPRECATED_API,
    * it is needed for layout of RuleBasedCollator object. */
#ifndef U_FORCE_HIDE_DEPRECATED_API
   /**
    * One more than the highest normal UColAttribute value.
    * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
    */
    UCOL_ATTRIBUTE_COUNT
#endif  // U_FORCE_HIDE_DEPRECATED_API
} UColAttribute;

/** Options for retrieving the rule string 
*  @stable ICU 2.0
*/
typedef enum {
 /**
  * Retrieves the tailoring rules only.
  * Same as calling the version of getRules() without UColRuleOption.
  * @stable ICU 2.0
  */
 UCOL_TAILORING_ONLY, 
 /**
  * Retrieves the "UCA rules" concatenated with the tailoring rules.
  * The "UCA rules" are an <i>approximation</i> of the root collator's sort order.
  * They are almost never used or useful at runtime and can be removed from the data.
  * See https://unicode-org.github.io/icu/userguide/collation/customization#building-on-existing-locales
  * @stable ICU 2.0
  */
 UCOL_FULL_RULES 
} UColRuleOption ;

/**
* Open a UCollator for comparing strings.
*
* For some languages, multiple collation types are available;
* for example, "de@collation=phonebook".
* Starting with ICU 54, 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 <a href="https://unicode-org.github.io/icu/userguide/collation/api">User Guide: Collation API</a>.
*
* The UCollator pointer is used in all the calls to the Collation 
* service. After finished, collator must be disposed of by calling
* {@link #ucol_close }.
* @param loc 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" are passed, the root collator will be returned.
* @param status A pointer to a UErrorCode to receive any errors
* @return A pointer to a UCollator, or 0 if an error occurred.
* @see ucol_openRules
* @see ucol_clone
* @see ucol_close
* @stable ICU 2.0
*/
U_CAPI UCollator* U_EXPORT2 
ucol_open(const char *loc, UErrorCode *status);

/**
* Produce a UCollator instance according to the rules supplied.
* The rules are used to change the default ordering, defined in the
* UCA in a process called tailoring. The resulting UCollator pointer
* can be used in the same way as the one obtained by {@link #ucol_open }.
* @param rules A string describing the collation rules. For the syntax
*              of the rules please see users guide.
* @param rulesLength The length of rules, or -1 if null-terminated.
* @param normalizationMode The normalization mode: One of
*             UCOL_OFF     (expect the text to not need normalization),
*             UCOL_ON      (normalize), or
*             UCOL_DEFAULT (set the mode according to the rules)
* @param strength The collation strength; one of UCOL_PRIMARY, UCOL_SECONDARY,
*                 UCOL_TERTIARY, UCOL_QUATERNARY, UCOL_IDENTICAL, UCOL_DEFAULT_STRENGTH.
*                 If you want to set the strength via the rules,
*                 then use UCOL_DEFAULT to not override that.
* @param parseError  A pointer to UParseError to receive information about errors
*                    occurred during parsing. This argument can currently be set
*                    to NULL, but at users own risk. Please provide a real structure.
* @param status A pointer to a UErrorCode to receive any errors
* @return A pointer to a UCollator. It is not guaranteed that NULL be returned in case
*         of error - please use status argument to check for errors.
* @see ucol_open
* @see ucol_clone
* @see ucol_close
* @stable ICU 2.0
*/
U_CAPI UCollator* U_EXPORT2 
ucol_openRules( const UChar        *rules,
               int32_t            rulesLength,
               UColAttributeValue normalizationMode,
               UCollationStrength strength,
               UParseError        *parseError,
               UErrorCode         *status);

#ifndef U_HIDE_DEPRECATED_API
/** 
* Open a collator defined by a short form string.
* The structure and the syntax of the string is defined in the "Naming collators"
* section of the users guide: 
* https://unicode-org.github.io/icu/userguide/collation/concepts#collator-naming-scheme
* Attributes are overridden by the subsequent attributes. So, for "S2_S3", final
* strength will be 3. 3066bis locale overrides individual locale parts.
* The call to this function is equivalent to a call to ucol_open, followed by a 
* series of calls to ucol_setAttribute and ucol_setVariableTop.
* @param definition A short string containing a locale and a set of attributes. 
*                   Attributes not explicitly mentioned are left at the default
*                   state for a locale.
* @param parseError if not NULL, structure that will get filled with error's pre
*                   and post context in case of error.
* @param forceDefaults if false, the settings that are the same as the collator 
*                   default settings will not be applied (for example, setting
*                   French secondary on a French collator would not be executed). 
*                   If true, all the settings will be applied regardless of the 
*                   collator default value. If the definition
*                   strings are to be cached, should be set to false.
* @param status     Error code. Apart from regular error conditions connected to 
*                   instantiating collators (like out of memory or similar), this
*                   API will return an error if an invalid attribute or attribute/value
*                   combination is specified.
* @return           A pointer to a UCollator or 0 if an error occurred (including an 
*                   invalid attribute).
* @see ucol_open
* @see ucol_setAttribute
* @see ucol_setVariableTop
* @see ucol_getShortDefinitionString
* @see ucol_normalizeShortDefinitionString
* @deprecated ICU 54 Use ucol_open() with language tag collation keywords instead.
*/
U_DEPRECATED UCollator* U_EXPORT2
ucol_openFromShortString( const char *definition,
                         UBool forceDefaults,
                         UParseError *parseError,
                         UErrorCode *status);
#endif  /* U_HIDE_DEPRECATED_API */

#ifndef U_HIDE_DEPRECATED_API
/**
* Get a set containing the contractions defined by the collator. The set includes
* both the root collator's contractions and the contractions defined by the collator. This set
* will contain only strings. If a tailoring explicitly suppresses contractions from 
* the root collator (like Russian), removed contractions will not be in the resulting set.
* @param coll collator 
* @param conts the set to hold the result. It gets emptied before
*              contractions are added. 
* @param status to hold the error code
* @return the size of the contraction set
*
* @deprecated ICU 3.4, use ucol_getContractionsAndExpansions instead
*/
U_DEPRECATED int32_t U_EXPORT2
ucol_getContractions( const UCollator *coll,
                 USet *conts,
                 UErrorCode *status);
#endif  /* U_HIDE_DEPRECATED_API */

/**
* Get a set containing the expansions defined by the collator. The set includes
* both the root collator's expansions and the expansions defined by the tailoring
* @param coll collator
* @param contractions if not NULL, the set to hold the contractions
* @param expansions if not NULL, the set to hold the expansions
* @param addPrefixes add the prefix contextual elements to contractions
* @param status to hold the error code
*
* @stable ICU 3.4
*/
U_CAPI void U_EXPORT2
ucol_getContractionsAndExpansions( const UCollator *coll,
                 USet *contractions, USet *expansions,
                 UBool addPrefixes, UErrorCode *status);

/** 
* Close a UCollator.
* Once closed, a UCollator should not be used. Every open collator should
* be closed. Otherwise, a memory leak will result.
* @param coll The UCollator to close.
* @see ucol_open
* @see ucol_openRules
* @see ucol_clone
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2 
ucol_close(UCollator *coll);

#if U_SHOW_CPLUSPLUS_API

U_NAMESPACE_BEGIN

/**
* \class LocalUCollatorPointer
* "Smart pointer" class, closes a UCollator via ucol_close().
* For most methods see the LocalPointerBase base class.
*
* @see LocalPointerBase
* @see LocalPointer
* @stable ICU 4.4
*/
U_DEFINE_LOCAL_OPEN_POINTER(LocalUCollatorPointer, UCollator, ucol_close);

U_NAMESPACE_END

#endif

/**
* Compare two strings.
* The strings will be compared using the options already specified.
* @param coll The UCollator containing the comparison rules.
* @param source The source string.
* @param sourceLength The length of source, or -1 if null-terminated.
* @param target The target string.
* @param targetLength The length of target, or -1 if null-terminated.
* @return The result of comparing the strings; one of UCOL_EQUAL,
* UCOL_GREATER, UCOL_LESS
* @see ucol_greater
* @see ucol_greaterOrEqual
* @see ucol_equal
* @stable ICU 2.0
*/
U_CAPI UCollationResult U_EXPORT2 
ucol_strcoll(    const    UCollator    *coll,
       const    UChar        *source,
       int32_t            sourceLength,
       const    UChar        *target,
       int32_t            targetLength);

/** 
* Compare two strings in UTF-8. 
* The strings will be compared using the options already specified. 
* Note: When input string contains malformed a UTF-8 byte sequence, 
* this function treats these bytes as REPLACEMENT CHARACTER (U+FFFD).
* @param coll The UCollator containing the comparison rules. 
* @param source The source UTF-8 string. 
* @param sourceLength The length of source, or -1 if null-terminated. 
* @param target The target UTF-8 string. 
* @param targetLength The length of target, or -1 if null-terminated. 
* @param status A pointer to a UErrorCode to receive any errors 
* @return The result of comparing the strings; one of UCOL_EQUAL, 
* UCOL_GREATER, UCOL_LESS 
* @see ucol_greater 
* @see ucol_greaterOrEqual 
* @see ucol_equal 
* @stable ICU 50 
*/ 
U_CAPI UCollationResult U_EXPORT2
ucol_strcollUTF8(
       const UCollator *coll,
       const char      *source,
       int32_t         sourceLength,
       const char      *target,
       int32_t         targetLength,
       UErrorCode      *status);

/**
* Determine if one string is greater than another.
* This function is equivalent to {@link #ucol_strcoll } == UCOL_GREATER
* @param coll The UCollator containing the comparison rules.
* @param source The source string.
* @param sourceLength The length of source, or -1 if null-terminated.
* @param target The target string.
* @param targetLength The length of target, or -1 if null-terminated.
* @return true if source is greater than target, false otherwise.
* @see ucol_strcoll
* @see ucol_greaterOrEqual
* @see ucol_equal
* @stable ICU 2.0
*/
U_CAPI UBool U_EXPORT2 
ucol_greater(const UCollator *coll,
            const UChar     *source, int32_t sourceLength,
            const UChar     *target, int32_t targetLength);

/**
* Determine if one string is greater than or equal to another.
* This function is equivalent to {@link #ucol_strcoll } != UCOL_LESS
* @param coll The UCollator containing the comparison rules.
* @param source The source string.
* @param sourceLength The length of source, or -1 if null-terminated.
* @param target The target string.
* @param targetLength The length of target, or -1 if null-terminated.
* @return true if source is greater than or equal to target, false otherwise.
* @see ucol_strcoll
* @see ucol_greater
* @see ucol_equal
* @stable ICU 2.0
*/
U_CAPI UBool U_EXPORT2 
ucol_greaterOrEqual(const UCollator *coll,
                   const UChar     *source, int32_t sourceLength,
                   const UChar     *target, int32_t targetLength);

/**
* Compare two strings for equality.
* This function is equivalent to {@link #ucol_strcoll } == UCOL_EQUAL
* @param coll The UCollator containing the comparison rules.
* @param source The source string.
* @param sourceLength The length of source, or -1 if null-terminated.
* @param target The target string.
* @param targetLength The length of target, or -1 if null-terminated.
* @return true if source is equal to target, false otherwise
* @see ucol_strcoll
* @see ucol_greater
* @see ucol_greaterOrEqual
* @stable ICU 2.0
*/
U_CAPI UBool U_EXPORT2 
ucol_equal(const UCollator *coll,
          const UChar     *source, int32_t sourceLength,
          const UChar     *target, int32_t targetLength);

/**
* Compare two UTF-8 encoded strings.
* The strings will be compared using the options already specified.
* @param coll The UCollator containing the comparison rules.
* @param sIter The source string iterator.
* @param tIter The target string iterator.
* @return The result of comparing the strings; one of UCOL_EQUAL,
* UCOL_GREATER, UCOL_LESS
* @param status A pointer to a UErrorCode to receive any errors
* @see ucol_strcoll
* @stable ICU 2.6
*/
U_CAPI UCollationResult U_EXPORT2 
ucol_strcollIter(  const    UCollator    *coll,
                 UCharIterator *sIter,
                 UCharIterator *tIter,
                 UErrorCode *status);

/**
* Get the collation strength used in a UCollator.
* The strength influences how strings are compared.
* @param coll The UCollator to query.
* @return The collation strength; one of UCOL_PRIMARY, UCOL_SECONDARY,
* UCOL_TERTIARY, UCOL_QUATERNARY, UCOL_IDENTICAL
* @see ucol_setStrength
* @stable ICU 2.0
*/
U_CAPI UCollationStrength U_EXPORT2 
ucol_getStrength(const UCollator *coll);

/**
* Set the collation strength used in a UCollator.
* The strength influences how strings are compared.
* @param coll The UCollator to set.
* @param strength The desired collation strength; one of UCOL_PRIMARY, 
* UCOL_SECONDARY, UCOL_TERTIARY, UCOL_QUATERNARY, UCOL_IDENTICAL, UCOL_DEFAULT
* @see ucol_getStrength
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2 
ucol_setStrength(UCollator *coll,
                UCollationStrength strength);

/**
* Retrieves the reordering codes for this collator.
* These reordering codes are a combination of UScript codes and UColReorderCode entries.
* @param coll The UCollator to query.
* @param dest The array to fill with the script ordering.
* @param destCapacity The length of dest. If it is 0, then dest may be NULL and the function 
* will only return the length of the result without writing any codes (pre-flighting).
* @param pErrorCode Must be a valid pointer to an error code value, which must not indicate a 
* failure before the function call.
* @return The number of reordering codes written to the dest array.
* @see ucol_setReorderCodes
* @see ucol_getEquivalentReorderCodes
* @see UScriptCode
* @see UColReorderCode
* @stable ICU 4.8
*/
U_CAPI int32_t U_EXPORT2 
ucol_getReorderCodes(const UCollator* coll,
                   int32_t* dest,
                   int32_t destCapacity,
                   UErrorCode *pErrorCode);
/** 
* Sets the reordering codes for this collator.
* Collation reordering allows scripts and some other groups of characters
* to be moved relative to each other. This reordering is done on top of
* the DUCET/CLDR standard collation order. Reordering can specify groups to be placed 
* at the start and/or the end of the collation order. These groups are specified using
* UScript codes and UColReorderCode entries.
*
* <p>By default, reordering codes specified for the start of the order are placed in the 
* order given after several special non-script blocks. These special groups of characters
* are space, punctuation, symbol, currency, and digit. These special groups are represented with
* UColReorderCode entries. Script groups can be intermingled with 
* these special non-script groups if those special groups are explicitly specified in the reordering.
*
* <p>The special code OTHERS stands for any script that is not explicitly 
* mentioned in the list of reordering codes given. Anything that is after OTHERS
* will go at the very end of the reordering in the order given.
*
* <p>The special reorder code DEFAULT will reset the reordering for this collator
* to the default for this collator. The default reordering may be the DUCET/CLDR order or may be a reordering that
* was specified when this collator was created from resource data or from rules. The 
* DEFAULT code <b>must</b> be the sole code supplied when it is used.
* If not, then U_ILLEGAL_ARGUMENT_ERROR will be set.
*
* <p>The special reorder code NONE will remove any reordering for this collator.
* The result of setting no reordering will be to have the DUCET/CLDR ordering used. The 
* NONE code <b>must</b> be the sole code supplied when it is used.
*
* @param coll The UCollator to set.
* @param reorderCodes An array of script codes in the new order. This can be NULL if the 
* length is also set to 0. An empty array will clear any reordering codes on the collator.
* @param reorderCodesLength The length of reorderCodes.
* @param pErrorCode Must be a valid pointer to an error code value, which must not indicate a
* failure before the function call.
* @see ucol_getReorderCodes
* @see ucol_getEquivalentReorderCodes
* @see UScriptCode
* @see UColReorderCode
* @stable ICU 4.8
*/ 
U_CAPI void U_EXPORT2 
ucol_setReorderCodes(UCollator* coll,
                   const int32_t* reorderCodes,
                   int32_t reorderCodesLength,
                   UErrorCode *pErrorCode);

/**
* Retrieves the reorder codes that are grouped with the given reorder code. Some reorder
* codes will be grouped and must reorder together.
* Beginning with ICU 55, scripts only reorder together if they are primary-equal,
* for example Hiragana and Katakana.
*
* @param reorderCode The reorder code to determine equivalence for.
* @param dest The array to fill with the script ordering.
* @param destCapacity The length of dest. If it is 0, then dest may be NULL and the function
* will only return the length of the result without writing any codes (pre-flighting).
* @param pErrorCode Must be a valid pointer to an error code value, which must not indicate 
* a failure before the function call.
* @return The number of reordering codes written to the dest array.
* @see ucol_setReorderCodes
* @see ucol_getReorderCodes
* @see UScriptCode
* @see UColReorderCode
* @stable ICU 4.8
*/
U_CAPI int32_t U_EXPORT2 
ucol_getEquivalentReorderCodes(int32_t reorderCode,
                   int32_t* dest,
                   int32_t destCapacity,
                   UErrorCode *pErrorCode);

/**
* Get the display name for a UCollator.
* The display name is suitable for presentation to a user.
* @param objLoc The locale of the collator in question.
* @param dispLoc The locale for display.
* @param result A pointer to a buffer to receive the attribute.
* @param resultLength The maximum size of result.
* @param status A pointer to a UErrorCode to receive any errors
* @return The total buffer size needed; if greater than resultLength,
* the output was truncated.
* @stable ICU 2.0
*/
U_CAPI int32_t U_EXPORT2 
ucol_getDisplayName(    const    char        *objLoc,
           const    char        *dispLoc,
           UChar             *result,
           int32_t         resultLength,
           UErrorCode        *status);

/**
* Get a locale for which collation rules are available.
* A UCollator in a locale returned by this function will perform the correct
* collation for the locale.
* @param localeIndex The index of the desired locale.
* @return A locale for which collation rules are available, or 0 if none.
* @see ucol_countAvailable
* @stable ICU 2.0
*/
U_CAPI const char* U_EXPORT2 
ucol_getAvailable(int32_t localeIndex);

/**
* Determine how many locales have collation rules available.
* This function is most useful as determining the loop ending condition for
* calls to {@link #ucol_getAvailable }.
* @return The number of locales for which collation rules are available.
* @see ucol_getAvailable
* @stable ICU 2.0
*/
U_CAPI int32_t U_EXPORT2 
ucol_countAvailable(void);

#if !UCONFIG_NO_SERVICE
/**
* Create a string enumerator of all locales for which a valid
* collator may be opened.
* @param status input-output error code
* @return a string enumeration over locale strings. The caller is
* responsible for closing the result.
* @stable ICU 3.0
*/
U_CAPI UEnumeration* U_EXPORT2
ucol_openAvailableLocales(UErrorCode *status);
#endif

/**
* Create a string enumerator of all possible keywords that are relevant to
* collation. At this point, the only recognized keyword for this
* service is "collation".
* @param status input-output error code
* @return a string enumeration over locale strings. The caller is
* responsible for closing the result.
* @stable ICU 3.0
*/
U_CAPI UEnumeration* U_EXPORT2
ucol_getKeywords(UErrorCode *status);

/**
* Given a keyword, create a string enumeration of all values
* for that keyword that are currently in use.
* @param keyword a particular keyword as enumerated by
* ucol_getKeywords. If any other keyword is passed in, *status is set
* to U_ILLEGAL_ARGUMENT_ERROR.
* @param status input-output error code
* @return a string enumeration over collation keyword values, or NULL
* upon error. The caller is responsible for closing the result.
* @stable ICU 3.0
*/
U_CAPI UEnumeration* U_EXPORT2
ucol_getKeywordValues(const char *keyword, UErrorCode *status);

/**
* Given a key and a locale, returns an array of string values in a preferred
* order that would make a difference. These are all and only those values where
* the open (creation) of the service with the locale formed from the input locale
* plus input keyword and that value has different behavior than creation with the
* input locale alone.
* @param key           one of the keys supported by this service.  For now, only
*                      "collation" is supported.
* @param locale        the locale
* @param commonlyUsed  if set to true it will return only commonly used values
*                      with the given locale in preferred order.  Otherwise,
*                      it will return all the available values for the locale.
* @param status error status
* @return a string enumeration over keyword values for the given key and the locale.
* @stable ICU 4.2
*/
U_CAPI UEnumeration* U_EXPORT2
ucol_getKeywordValuesForLocale(const char* key,
                              const char* locale,
                              UBool commonlyUsed,
                              UErrorCode* status);

/**
* Return the functionally equivalent locale for the specified
* input locale, with respect to given keyword, for the
* collation service. If two different input locale + keyword
* combinations produce the same result locale, then collators
* instantiated for these two different input locales will behave
* equivalently. The converse is not always true; two collators
* may in fact be equivalent, but return different results, due to
* internal details. The return result has no other meaning than
* that stated above, and implies nothing as to the relationship
* between the two locales. This is intended for use by
* applications who wish to cache collators, or otherwise reuse
* collators when possible. The functional equivalent may change
* over time. For more information, please see the <a
* href="https://unicode-org.github.io/icu/userguide/locale#locales-and-services">
* Locales and Services</a> section of the ICU User Guide.
* @param result fillin for the functionally equivalent result locale
* @param resultCapacity capacity of the fillin buffer
* @param keyword a particular keyword as enumerated by
* ucol_getKeywords.
* @param locale the specified input locale
* @param isAvailable if non-NULL, pointer to a fillin parameter that
* on return indicates whether the specified input locale was 'available'
* to the collation service. A locale is defined as 'available' if it
* physically exists within the collation locale data.
* @param status pointer to input-output error code
* @return the actual buffer size needed for the locale. If greater
* than resultCapacity, the returned full name will be truncated and
* an error code will be returned.
* @stable ICU 3.0
*/
U_CAPI int32_t U_EXPORT2
ucol_getFunctionalEquivalent(char* result, int32_t resultCapacity,
                            const char* keyword, const char* locale,
                            UBool* isAvailable, UErrorCode* status);

/**
* Get the collation tailoring rules from a UCollator.
* The rules will follow the rule syntax.
* @param coll The UCollator to query.
* @param length 
* @return The collation tailoring rules.
* @stable ICU 2.0
*/
U_CAPI const UChar* U_EXPORT2 
ucol_getRules(    const    UCollator    *coll, 
       int32_t            *length);

#ifndef U_HIDE_DEPRECATED_API
/** Get the short definition string for a collator. This API harvests the collator's
*  locale and the attribute set and produces a string that can be used for opening 
*  a collator with the same attributes using the ucol_openFromShortString API.
*  This string will be normalized.
*  The structure and the syntax of the string is defined in the "Naming collators"
*  section of the users guide: 
*  https://unicode-org.github.io/icu/userguide/collation/concepts#collator-naming-scheme
*  This API supports preflighting.
*  @param coll a collator
*  @param locale a locale that will appear as a collators locale in the resulting
*                short string definition. If NULL, the locale will be harvested 
*                from the collator.
*  @param buffer space to hold the resulting string
*  @param capacity capacity of the buffer
*  @param status for returning errors. All the preflighting errors are featured
*  @return length of the resulting string
*  @see ucol_openFromShortString
*  @see ucol_normalizeShortDefinitionString
*  @deprecated ICU 54
*/
U_DEPRECATED int32_t U_EXPORT2
ucol_getShortDefinitionString(const UCollator *coll,
                             const char *locale,
                             char *buffer,
                             int32_t capacity,
                             UErrorCode *status);

/** Verifies and normalizes short definition string.
*  Normalized short definition string has all the option sorted by the argument name,
*  so that equivalent definition strings are the same. 
*  This API supports preflighting.
*  @param source definition string
*  @param destination space to hold the resulting string
*  @param capacity capacity of the buffer
*  @param parseError if not NULL, structure that will get filled with error's pre
*                   and post context in case of error.
*  @param status     Error code. This API will return an error if an invalid attribute 
*                    or attribute/value combination is specified. All the preflighting 
*                    errors are also featured
*  @return length of the resulting normalized string.
*
*  @see ucol_openFromShortString
*  @see ucol_getShortDefinitionString
* 
*  @deprecated ICU 54
*/
U_DEPRECATED int32_t U_EXPORT2
ucol_normalizeShortDefinitionString(const char *source,
                                   char *destination,
                                   int32_t capacity,
                                   UParseError *parseError,
                                   UErrorCode *status);
#endif  /* U_HIDE_DEPRECATED_API */


/**
* Get a sort key for a string from a UCollator.
* Sort keys may be compared using <TT>strcmp</TT>.
*
* Note that sort keys are often less efficient than simply doing comparison.  
* For more details, see the ICU User Guide.
*
* Like ICU functions that write to an output buffer, the buffer contents
* is undefined if the buffer capacity (resultLength parameter) is too small.
* Unlike ICU functions that write a string to an output buffer,
* the terminating zero byte is counted in the sort key length.
* @param coll The UCollator containing the collation rules.
* @param source The string to transform.
* @param sourceLength The length of source, or -1 if null-terminated.
* @param result A pointer to a buffer to receive the attribute.
* @param resultLength The maximum size of result.
* @return The size needed to fully store the sort key.
*      If there was an internal error generating the sort key,
*      a zero value is returned.
* @see ucol_keyHashCode
* @stable ICU 2.0
*/
U_CAPI int32_t U_EXPORT2 
ucol_getSortKey(const    UCollator    *coll,
       const    UChar        *source,
       int32_t        sourceLength,
       uint8_t        *result,
       int32_t        resultLength);


/** Gets the next count bytes of a sort key. Caller needs
*  to preserve state array between calls and to provide
*  the same type of UCharIterator set with the same string.
*  The destination buffer provided must be big enough to store
*  the number of requested bytes.
*
*  The generated sort key may or may not be compatible with
*  sort keys generated using ucol_getSortKey().
*  @param coll The UCollator containing the collation rules.
*  @param iter UCharIterator containing the string we need 
*              the sort key to be calculated for.
*  @param state Opaque state of sortkey iteration.
*  @param dest Buffer to hold the resulting sortkey part
*  @param count number of sort key bytes required.
*  @param status error code indicator.
*  @return the actual number of bytes of a sortkey. It can be
*          smaller than count if we have reached the end of 
*          the sort key.
*  @stable ICU 2.6
*/
U_CAPI int32_t U_EXPORT2 
ucol_nextSortKeyPart(const UCollator *coll,
                    UCharIterator *iter,
                    uint32_t state[2],
                    uint8_t *dest, int32_t count,
                    UErrorCode *status);

/** enum that is taken by ucol_getBound API 
* See below for explanation                
* do not change the values assigned to the 
* members of this enum. Underlying code    
* depends on them having these numbers     
* @stable ICU 2.0
*/
typedef enum {
 /** lower bound */
 UCOL_BOUND_LOWER = 0,
 /** upper bound that will match strings of exact size */
 UCOL_BOUND_UPPER = 1,
 /** upper bound that will match all the strings that have the same initial substring as the given string */
 UCOL_BOUND_UPPER_LONG = 2,
#ifndef U_HIDE_DEPRECATED_API
   /**
    * One more than the highest normal UColBoundMode value.
    * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
    */
   UCOL_BOUND_VALUE_COUNT
#endif  /* U_HIDE_DEPRECATED_API */
} UColBoundMode;

/**
* Produce a bound for a given sortkey and a number of levels.
* Return value is always the number of bytes needed, regardless of 
* whether the result buffer was big enough or even valid.<br>
* Resulting bounds can be used to produce a range of strings that are
* between upper and lower bounds. For example, if bounds are produced
* for a sortkey of string "smith", strings between upper and lower 
* bounds with one level would include "Smith", "SMITH", "sMiTh".<br>
* There are two upper bounds that can be produced. If UCOL_BOUND_UPPER
* is produced, strings matched would be as above. However, if bound
* produced using UCOL_BOUND_UPPER_LONG is used, the above example will
* also match "Smithsonian" and similar.<br>
* For more on usage, see example in cintltst/capitst.c in procedure
* TestBounds.
* Sort keys may be compared using <TT>strcmp</TT>.
* @param source The source sortkey.
* @param sourceLength The length of source, or -1 if null-terminated. 
*                     (If an unmodified sortkey is passed, it is always null 
*                      terminated).
* @param boundType Type of bound required. It can be UCOL_BOUND_LOWER, which 
*                  produces a lower inclusive bound, UCOL_BOUND_UPPER, that 
*                  produces upper bound that matches strings of the same length 
*                  or UCOL_BOUND_UPPER_LONG that matches strings that have the 
*                  same starting substring as the source string.
* @param noOfLevels  Number of levels required in the resulting bound (for most 
*                    uses, the recommended value is 1). See users guide for 
*                    explanation on number of levels a sortkey can have.
* @param result A pointer to a buffer to receive the resulting sortkey.
* @param resultLength The maximum size of result.
* @param status Used for returning error code if something went wrong. If the 
*               number of levels requested is higher than the number of levels
*               in the source key, a warning (U_SORT_KEY_TOO_SHORT_WARNING) is 
*               issued.
* @return The size needed to fully store the bound. 
* @see ucol_keyHashCode
* @stable ICU 2.1
*/
U_CAPI int32_t U_EXPORT2 
ucol_getBound(const uint8_t       *source,
       int32_t             sourceLength,
       UColBoundMode       boundType,
       uint32_t            noOfLevels,
       uint8_t             *result,
       int32_t             resultLength,
       UErrorCode          *status);
       
/**
* Gets the version information for a Collator. Version is currently
* an opaque 32-bit number which depends, among other things, on major
* versions of the collator tailoring and UCA.
* @param coll The UCollator to query.
* @param info the version # information, the result will be filled in
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2
ucol_getVersion(const UCollator* coll, UVersionInfo info);

/**
* Gets the UCA version information for a Collator. Version is the
* UCA version number (3.1.1, 4.0).
* @param coll The UCollator to query.
* @param info the version # information, the result will be filled in
* @stable ICU 2.8
*/
U_CAPI void U_EXPORT2
ucol_getUCAVersion(const UCollator* coll, UVersionInfo info);

/**
* Merges two sort keys. The levels are merged with their corresponding counterparts
* (primaries with primaries, secondaries with secondaries etc.). Between the values
* from the same level a separator is inserted.
*
* This is useful, for example, for combining sort keys from first and last names
* to sort such pairs.
* See http://www.unicode.org/reports/tr10/#Merging_Sort_Keys
*
* The recommended way to achieve "merged" sorting is by
* concatenating strings with U+FFFE between them.
* The concatenation has the same sort order as the merged sort keys,
* but merge(getSortKey(str1), getSortKey(str2)) may differ from getSortKey(str1 + '\\uFFFE' + str2).
* Using strings with U+FFFE may yield shorter sort keys.
*
* For details about Sort Key Features see
* https://unicode-org.github.io/icu/userguide/collation/api#sort-key-features
*
* It is possible to merge multiple sort keys by consecutively merging
* another one with the intermediate result.
*
* The length of the merge result is the sum of the lengths of the input sort keys.
*
* Example (uncompressed):
* <pre>191B1D 01 050505 01 910505 00
* 1F2123 01 050505 01 910505 00</pre>
* will be merged as 
* <pre>191B1D 02 1F2123 01 050505 02 050505 01 910505 02 910505 00</pre>
*
* If the destination buffer is not big enough, then its contents are undefined.
* If any of source lengths are zero or any of the source pointers are NULL/undefined,
* the result is of size zero.
*
* @param src1 the first sort key
* @param src1Length the length of the first sort key, including the zero byte at the end;
*        can be -1 if the function is to find the length
* @param src2 the second sort key
* @param src2Length the length of the second sort key, including the zero byte at the end;
*        can be -1 if the function is to find the length
* @param dest the buffer where the merged sort key is written,
*        can be NULL if destCapacity==0
* @param destCapacity the number of bytes in the dest buffer
* @return the length of the merged sort key, src1Length+src2Length;
*         can be larger than destCapacity, or 0 if an error occurs (only for illegal arguments),
*         in which cases the contents of dest is undefined
* @stable ICU 2.0
*/
U_CAPI int32_t U_EXPORT2 
ucol_mergeSortkeys(const uint8_t *src1, int32_t src1Length,
                  const uint8_t *src2, int32_t src2Length,
                  uint8_t *dest, int32_t destCapacity);

/**
* Universal attribute setter
* @param coll collator which attributes are to be changed
* @param attr attribute type 
* @param value attribute value
* @param status to indicate whether the operation went on smoothly or there were errors
* @see UColAttribute
* @see UColAttributeValue
* @see ucol_getAttribute
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2 
ucol_setAttribute(UCollator *coll, UColAttribute attr, UColAttributeValue value, UErrorCode *status);

/**
* Universal attribute getter
* @param coll collator which attributes are to be changed
* @param attr attribute type
* @return attribute value
* @param status to indicate whether the operation went on smoothly or there were errors
* @see UColAttribute
* @see UColAttributeValue
* @see ucol_setAttribute
* @stable ICU 2.0
*/
U_CAPI UColAttributeValue  U_EXPORT2 
ucol_getAttribute(const UCollator *coll, UColAttribute attr, UErrorCode *status);

/**
* Sets the variable top to the top of the specified reordering group.
* The variable top determines the highest-sorting character
* which is affected by UCOL_ALTERNATE_HANDLING.
* If that attribute is set to UCOL_NON_IGNORABLE, then the variable top has no effect.
* @param coll the collator
* @param group one of UCOL_REORDER_CODE_SPACE, UCOL_REORDER_CODE_PUNCTUATION,
*              UCOL_REORDER_CODE_SYMBOL, UCOL_REORDER_CODE_CURRENCY;
*              or UCOL_REORDER_CODE_DEFAULT to restore the default max variable group
* @param pErrorCode Standard ICU error code. Its input value must
*                   pass the U_SUCCESS() test, or else the function returns
*                   immediately. Check for U_FAILURE() on output or use with
*                   function chaining. (See User Guide for details.)
* @see ucol_getMaxVariable
* @stable ICU 53
*/
U_CAPI void U_EXPORT2
ucol_setMaxVariable(UCollator *coll, UColReorderCode group, UErrorCode *pErrorCode);

/**
* Returns the maximum reordering group whose characters are affected by UCOL_ALTERNATE_HANDLING.
* @param coll the collator
* @return the maximum variable reordering group.
* @see ucol_setMaxVariable
* @stable ICU 53
*/
U_CAPI UColReorderCode U_EXPORT2
ucol_getMaxVariable(const UCollator *coll);

#ifndef U_HIDE_DEPRECATED_API
/**
* Sets the variable top to the primary weight of the specified string.
*
* Beginning with ICU 53, the variable top is pinned to
* the top of one of the supported reordering groups,
* and it must not be beyond the last of those groups.
* See ucol_setMaxVariable().
* @param coll the collator
* @param varTop one or more (if contraction) UChars to which the variable top should be set
* @param len length of variable top string. If -1 it is considered to be zero terminated.
* @param status error code. If error code is set, the return value is undefined.
*               Errors set by this function are:<br>
*    U_CE_NOT_FOUND_ERROR if more than one character was passed and there is no such contraction<br>
*    U_ILLEGAL_ARGUMENT_ERROR if the variable top is beyond
*    the last reordering group supported by ucol_setMaxVariable()
* @return variable top primary weight
* @see ucol_getVariableTop
* @see ucol_restoreVariableTop
* @deprecated ICU 53 Call ucol_setMaxVariable() instead.
*/
U_DEPRECATED uint32_t U_EXPORT2 
ucol_setVariableTop(UCollator *coll, 
                   const UChar *varTop, int32_t len, 
                   UErrorCode *status);
#endif  /* U_HIDE_DEPRECATED_API */

/** 
* Gets the variable top value of a Collator. 
* @param coll collator which variable top needs to be retrieved
* @param status error code (not changed by function). If error code is set, 
*               the return value is undefined.
* @return the variable top primary weight
* @see ucol_getMaxVariable
* @see ucol_setVariableTop
* @see ucol_restoreVariableTop
* @stable ICU 2.0
*/
U_CAPI uint32_t U_EXPORT2 ucol_getVariableTop(const UCollator *coll, UErrorCode *status);

#ifndef U_HIDE_DEPRECATED_API
/**
* Sets the variable top to the specified primary weight.
*
* Beginning with ICU 53, the variable top is pinned to
* the top of one of the supported reordering groups,
* and it must not be beyond the last of those groups.
* See ucol_setMaxVariable().
* @param coll collator to be set
* @param varTop primary weight, as returned by ucol_setVariableTop or ucol_getVariableTop
* @param status error code
* @see ucol_getVariableTop
* @see ucol_setVariableTop
* @deprecated ICU 53 Call ucol_setMaxVariable() instead.
*/
U_DEPRECATED void U_EXPORT2 
ucol_restoreVariableTop(UCollator *coll, const uint32_t varTop, UErrorCode *status);
#endif  /* U_HIDE_DEPRECATED_API */

/**
* Thread safe cloning operation. The result is a clone of a given collator.
* @param coll collator to be cloned
* @param status to indicate whether the operation went on smoothly or there were errors
* @return pointer to the new clone
* @see ucol_open
* @see ucol_openRules
* @see ucol_close
* @stable ICU 71
*/
U_CAPI UCollator* U_EXPORT2 ucol_clone(const UCollator *coll, UErrorCode *status);

#ifndef U_HIDE_DEPRECATED_API

/**
* Thread safe cloning operation. The result is a clone of a given collator.
* @param coll collator to be cloned
* @param stackBuffer <em>Deprecated functionality as of ICU 52, use NULL.</em><br>
* user allocated space for the new clone. 
* If NULL new memory will be allocated. 
*  If buffer is not large enough, new memory will be allocated.
*  Clients can use the U_COL_SAFECLONE_BUFFERSIZE.
* @param pBufferSize <em>Deprecated functionality as of ICU 52, use NULL or 1.</em><br>
*  pointer to size of allocated space. 
*  If *pBufferSize == 0, a sufficient size for use in cloning will 
*  be returned ('pre-flighting')
*  If *pBufferSize is not enough for a stack-based safe clone, 
*  new memory will be allocated.
* @param status to indicate whether the operation went on smoothly or there were errors
*    An informational status value, U_SAFECLONE_ALLOCATED_ERROR, is used
* if pBufferSize != NULL and any allocations were necessary
* @return pointer to the new clone
* @see ucol_open
* @see ucol_openRules
* @see ucol_close
* @deprecated ICU 71 Use ucol_clone() instead.
*/
U_DEPRECATED UCollator* U_EXPORT2
ucol_safeClone(const UCollator *coll,
              void            *stackBuffer,
              int32_t         *pBufferSize,
              UErrorCode      *status);


/** default memory size for the new clone.
* @deprecated ICU 52. Do not rely on ucol_safeClone() cloning into any provided buffer.
*/
#define U_COL_SAFECLONE_BUFFERSIZE 1

#endif /* U_HIDE_DEPRECATED_API */

/**
* Returns current rules. Delta defines whether full rules are returned or just the tailoring. 
* Returns number of UChars needed to store rules. If buffer is NULL or bufferLen is not enough 
* to store rules, will store up to available space.
*
* ucol_getRules() should normally be used instead.
* See https://unicode-org.github.io/icu/userguide/collation/customization#building-on-existing-locales
* @param coll collator to get the rules from
* @param delta one of UCOL_TAILORING_ONLY, UCOL_FULL_RULES. 
* @param buffer buffer to store the result in. If NULL, you'll get no rules.
* @param bufferLen length of buffer to store rules in. If less than needed you'll get only the part that fits in.
* @return current rules
* @stable ICU 2.0
* @see UCOL_FULL_RULES
*/
U_CAPI int32_t U_EXPORT2 
ucol_getRulesEx(const UCollator *coll, UColRuleOption delta, UChar *buffer, int32_t bufferLen);

#ifndef U_HIDE_DEPRECATED_API
/**
* gets the locale name of the collator. If the collator
* is instantiated from the rules, then this function returns
* NULL.
* @param coll The UCollator for which the locale is needed
* @param type You can choose between requested, valid and actual
*             locale. For description see the definition of
*             ULocDataLocaleType in uloc.h
* @param status error code of the operation
* @return real locale name from which the collation data comes. 
*         If the collator was instantiated from rules, returns
*         NULL.
* @deprecated ICU 2.8 Use ucol_getLocaleByType instead
*/
U_DEPRECATED const char * U_EXPORT2
ucol_getLocale(const UCollator *coll, ULocDataLocaleType type, UErrorCode *status);
#endif  /* U_HIDE_DEPRECATED_API */

/**
* gets the locale name of the collator. If the collator
* is instantiated from the rules, then this function returns
* NULL.
* @param coll The UCollator for which the locale is needed
* @param type You can choose between requested, valid and actual
*             locale. For description see the definition of
*             ULocDataLocaleType in uloc.h
* @param status error code of the operation
* @return real locale name from which the collation data comes. 
*         If the collator was instantiated from rules, returns
*         NULL.
* @stable ICU 2.8
*/
U_CAPI const char * U_EXPORT2
ucol_getLocaleByType(const UCollator *coll, ULocDataLocaleType type, UErrorCode *status);

/**
* Get a Unicode set that contains all the characters and sequences tailored in 
* this collator. The result must be disposed of by using uset_close.
* @param coll        The UCollator for which we want to get tailored chars
* @param status      error code of the operation
* @return a pointer to newly created USet. Must be be disposed by using uset_close
* @see ucol_openRules
* @see uset_close
* @stable ICU 2.4
*/
U_CAPI USet * U_EXPORT2
ucol_getTailoredSet(const UCollator *coll, UErrorCode *status);

#ifndef U_HIDE_INTERNAL_API
/** Calculates the set of unsafe code points, given a collator.
*   A character is unsafe if you could append any character and cause the ordering to alter significantly.
*   Collation sorts in normalized order, so anything that rearranges in normalization can cause this.
*   Thus if you have a character like a_umlaut, and you add a lower_dot to it,
*   then it normalizes to a_lower_dot + umlaut, and sorts differently.
*  @param coll Collator
*  @param unsafe a fill-in set to receive the unsafe points
*  @param status for catching errors
*  @return number of elements in the set
*  @internal ICU 3.0
*/
U_CAPI int32_t U_EXPORT2
ucol_getUnsafeSet( const UCollator *coll,
                 USet *unsafe,
                 UErrorCode *status);

/** Touches all resources needed for instantiating a collator from a short string definition,
*  thus filling up the cache.
* @param definition A short string containing a locale and a set of attributes. 
*                   Attributes not explicitly mentioned are left at the default
*                   state for a locale.
* @param parseError if not NULL, structure that will get filled with error's pre
*                   and post context in case of error.
* @param forceDefaults if false, the settings that are the same as the collator 
*                   default settings will not be applied (for example, setting
*                   French secondary on a French collator would not be executed). 
*                   If true, all the settings will be applied regardless of the 
*                   collator default value. If the definition
*                   strings are to be cached, should be set to false.
* @param status     Error code. Apart from regular error conditions connected to 
*                   instantiating collators (like out of memory or similar), this
*                   API will return an error if an invalid attribute or attribute/value
*                   combination is specified.
* @see ucol_openFromShortString
* @internal ICU 3.2.1
*/
U_CAPI void U_EXPORT2
ucol_prepareShortStringOpen( const char *definition,
                         UBool forceDefaults,
                         UParseError *parseError,
                         UErrorCode *status);
#endif  /* U_HIDE_INTERNAL_API */

/** Creates a binary image of a collator. This binary image can be stored and 
*  later used to instantiate a collator using ucol_openBinary.
*  This API supports preflighting.
*  @param coll Collator
*  @param buffer a fill-in buffer to receive the binary image
*  @param capacity capacity of the destination buffer
*  @param status for catching errors
*  @return size of the image
*  @see ucol_openBinary
*  @stable ICU 3.2
*/
U_CAPI int32_t U_EXPORT2
ucol_cloneBinary(const UCollator *coll,
                uint8_t *buffer, int32_t capacity,
                UErrorCode *status);

/** Opens a collator from a collator binary image created using
*  ucol_cloneBinary. Binary image used in instantiation of the 
*  collator remains owned by the user and should stay around for 
*  the lifetime of the collator. The API also takes a base collator
*  which must be the root collator.
*  @param bin binary image owned by the user and required through the
*             lifetime of the collator
*  @param length size of the image. If negative, the API will try to
*                figure out the length of the image
*  @param base Base collator, for lookup of untailored characters.
*              Must be the root collator, must not be NULL.
*              The base is required to be present through the lifetime of the collator.
*  @param status for catching errors
*  @return newly created collator
*  @see ucol_cloneBinary
*  @stable ICU 3.2
*/
U_CAPI UCollator* U_EXPORT2
ucol_openBinary(const uint8_t *bin, int32_t length, 
               const UCollator *base, 
               UErrorCode *status);

#if U_SHOW_CPLUSPLUS_API || U_SHOW_CPLUSPLUS_HEADER_API

#include <functional>
#include <string_view>
#include <type_traits>

#include "unicode/char16ptr.h"
#include "unicode/unistr.h"

namespace U_HEADER_ONLY_NAMESPACE {

namespace collator {

namespace internal {

/**
* Function object for performing comparisons using a UCollator.
* @internal
*/
template <template <typename...> typename Compare, UCollationResult result>
class Predicate {
 public:
   /** @internal */
   explicit Predicate(const UCollator* ucol) : collator(ucol) {}

#if U_SHOW_CPLUSPLUS_API
   /** @internal */
   template <
       typename T, typename U,
       typename = std::enable_if_t<ConvertibleToU16StringView<T> && ConvertibleToU16StringView<U>>>
   bool operator()(const T& lhs, const U& rhs) const {
       return match(UnicodeString::readOnlyAlias(lhs), UnicodeString::readOnlyAlias(rhs));
   }
#else
   /** @internal */
   bool operator()(std::u16string_view lhs, std::u16string_view rhs) const {
       return match(lhs, rhs);
   }

#if !U_CHAR16_IS_TYPEDEF && (!defined(_LIBCPP_VERSION) || _LIBCPP_VERSION < 180000)
   /** @internal */
   bool operator()(std::basic_string_view<uint16_t> lhs, std::basic_string_view<uint16_t> rhs) const {
       return match({uprv_char16PtrFromUint16(lhs.data()), lhs.length()},
                    {uprv_char16PtrFromUint16(rhs.data()), rhs.length()});
   }
#endif

#if U_SIZEOF_WCHAR_T==2
   /** @internal */
   bool operator()(std::wstring_view lhs, std::wstring_view rhs) const {
       return match({uprv_char16PtrFromWchar(lhs.data()), lhs.length()},
                    {uprv_char16PtrFromWchar(rhs.data()), rhs.length()});
   }
#endif
#endif

   /** @internal */
   bool operator()(std::string_view lhs, std::string_view rhs) const {
       return match(lhs, rhs);
   }

#if defined(__cpp_char8_t)
   /** @internal */
   bool operator()(std::u8string_view lhs, std::u8string_view rhs) const {
       return match({reinterpret_cast<const char*>(lhs.data()), lhs.length()},
                    {reinterpret_cast<const char*>(rhs.data()), rhs.length()});
   }
#endif

 private:
   bool match(std::u16string_view lhs, std::u16string_view rhs) const {
       return compare(
           ucol_strcoll(
               collator,
               toUCharPtr(lhs.data()), static_cast<int32_t>(lhs.length()),
               toUCharPtr(rhs.data()), static_cast<int32_t>(rhs.length())),
           result);
   }

   bool match(std::string_view lhs, std::string_view rhs) const {
       UErrorCode status = U_ZERO_ERROR;
       return compare(
           ucol_strcollUTF8(
               collator,
               lhs.data(), static_cast<int32_t>(lhs.length()),
               rhs.data(), static_cast<int32_t>(rhs.length()),
               &status),
           result);
   }

   const UCollator* const collator;
   static constexpr Compare<UCollationResult> compare{};
};

}  // namespace internal

/**
* Function object for performing comparisons using this collator.
* Like <code>std::equal_to</code> but uses the collator instead of <code>operator==</code>.
* @stable ICU 76
*/
using equal_to = internal::Predicate<std::equal_to, UCOL_EQUAL>;

/**
* Function object for performing comparisons using this collator.
* Like <code>std::greater</code> but uses the collator instead of <code>operator&gt;</code>.
* @stable ICU 76
*/
using greater = internal::Predicate<std::equal_to, UCOL_GREATER>;

/**
* Function object for performing comparisons using this collator.
* Like <code>std::less</code> but uses the collator instead of <code>operator&lt;</code>.
* @stable ICU 76
*/
using less = internal::Predicate<std::equal_to, UCOL_LESS>;

/**
* Function object for performing comparisons using this collator.
* Like <code>std::not_equal_to</code> but uses the collator instead of <code>operator!=</code>.
* @stable ICU 76
*/
using not_equal_to = internal::Predicate<std::not_equal_to, UCOL_EQUAL>;

/**
* Function object for performing comparisons using this collator.
* Like <code>std::greater_equal</code> but uses the collator instead of <code>operator&gt;=</code>.
* @stable ICU 76
*/
using greater_equal = internal::Predicate<std::not_equal_to, UCOL_LESS>;

/**
* Function object for performing comparisons using this collator.
* Like <code>std::less_equal</code> but uses the collator instead of <code>operator&lt;=</code>.
* @stable ICU 76
*/
using less_equal = internal::Predicate<std::not_equal_to, UCOL_GREATER>;

}  // namespace collator

}  // namespace U_HEADER_ONLY_NAMESPACE

#endif  // U_SHOW_CPLUSPLUS_API || U_SHOW_CPLUSPLUS_HEADER_API

#endif /* #if !UCONFIG_NO_COLLATION */

#endif