JavaScriptGlue/icu/unicode/ucnv.h
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     1 /*
       
     2 **********************************************************************
       
     3 *   Copyright (C) 1999-2004, International Business Machines
       
     4 *   Corporation and others.  All Rights Reserved.
       
     5 **********************************************************************
       
     6  *  ucnv.h:
       
     7  *  External APIs for the ICU's codeset conversion library
       
     8  *  Bertrand A. Damiba
       
     9  *
       
    10  * Modification History:
       
    11  *
       
    12  *   Date        Name        Description
       
    13  *   04/04/99    helena      Fixed internal header inclusion.
       
    14  *   05/11/00    helena      Added setFallback and usesFallback APIs.
       
    15  *   06/29/2000  helena      Major rewrite of the callback APIs.
       
    16  *   12/07/2000  srl         Update of documentation
       
    17  */
       
    18 
       
    19 /**
       
    20  * \file
       
    21  * \brief C API: Character conversion 
       
    22  *
       
    23  * <h2>Character Conversion C API</h2>
       
    24  *
       
    25  * <p>This API is used to convert codepage or character encoded data to and
       
    26  * from UTF-16. You can open a converter with {@link ucnv_open() }. With that
       
    27  * converter, you can get its properties, set options, convert your data and
       
    28  * close the converter.</p>
       
    29  *
       
    30  * <p>Since many software programs recogize different converter names for
       
    31  * different types of converters, there are other functions in this API to
       
    32  * iterate over the converter aliases. The functions {@link ucnv_getAvailableName() },
       
    33  * {@link ucnv_getAlias() } and {@link ucnv_getStandardName() } are some of the
       
    34  * more frequently used alias functions to get this information.</p>
       
    35  *
       
    36  * <p>When a converter encounters an illegal, irregular, invalid or unmappable character
       
    37  * its default behavior is to use a substitution character to replace the
       
    38  * bad byte sequence. This behavior can be changed by using {@link ucnv_getFromUCallBack() }
       
    39  * or {@link ucnv_getToUCallBack() } on the converter. The header ucnv_err.h defines
       
    40  * many other callback actions that can be used instead of a character substitution.</p>
       
    41  *
       
    42  * <p>More information about this API can be found in our 
       
    43  * <a href="http://oss.software.ibm.com/icu/userguide/conversion.html">User's
       
    44  * Guide</a>.</p>
       
    45  */
       
    46 
       
    47 #ifndef UCNV_H
       
    48 #define UCNV_H
       
    49 
       
    50 #include "unicode/ucnv_err.h"
       
    51 #include "unicode/uenum.h"
       
    52 
       
    53 #ifndef __USET_H__
       
    54 
       
    55 /**
       
    56  * USet is the C API type for Unicode sets.
       
    57  * It is forward-declared here to avoid including the header file if related
       
    58  * conversion APIs are not used.
       
    59  * See unicode/uset.h
       
    60  *
       
    61  * @see ucnv_getUnicodeSet
       
    62  * @stable ICU 2.6
       
    63  */
       
    64 struct USet;
       
    65 /** @stable ICU 2.6 */
       
    66 typedef struct USet USet;
       
    67 
       
    68 #endif
       
    69 
       
    70 #if !UCONFIG_NO_CONVERSION
       
    71 
       
    72 U_CDECL_BEGIN
       
    73 
       
    74 /** Maximum length of a converter name including the terminating NULL @stable ICU 2.0 */
       
    75 #define UCNV_MAX_CONVERTER_NAME_LENGTH 60
       
    76 /** Maximum length of a converter name including path and terminating NULL @stable ICU 2.0 */
       
    77 #define UCNV_MAX_FULL_FILE_NAME_LENGTH (600+UCNV_MAX_CONVERTER_NAME_LENGTH)
       
    78 
       
    79 /** Shift in for EBDCDIC_STATEFUL and iso2022 states @stable ICU 2.0 */
       
    80 #define  UCNV_SI 0x0F
       
    81 /** Shift out for EBDCDIC_STATEFUL and iso2022 states @stable ICU 2.0 */
       
    82 #define  UCNV_SO 0x0E
       
    83 
       
    84 /**
       
    85  * Enum for specifying basic types of converters
       
    86  * @see ucnv_getType
       
    87  * @stable ICU 2.0
       
    88  */
       
    89 typedef enum {
       
    90     UCNV_UNSUPPORTED_CONVERTER = -1,
       
    91     UCNV_SBCS = 0,
       
    92     UCNV_DBCS = 1,
       
    93     UCNV_MBCS = 2,
       
    94     UCNV_LATIN_1 = 3,
       
    95     UCNV_UTF8 = 4,
       
    96     UCNV_UTF16_BigEndian = 5,
       
    97     UCNV_UTF16_LittleEndian = 6,
       
    98     UCNV_UTF32_BigEndian = 7,
       
    99     UCNV_UTF32_LittleEndian = 8,
       
   100     UCNV_EBCDIC_STATEFUL = 9,
       
   101     UCNV_ISO_2022 = 10,
       
   102 
       
   103     UCNV_LMBCS_1 = 11,
       
   104     UCNV_LMBCS_2, 
       
   105     UCNV_LMBCS_3,
       
   106     UCNV_LMBCS_4,
       
   107     UCNV_LMBCS_5,
       
   108     UCNV_LMBCS_6,
       
   109     UCNV_LMBCS_8,
       
   110     UCNV_LMBCS_11,
       
   111     UCNV_LMBCS_16,
       
   112     UCNV_LMBCS_17,
       
   113     UCNV_LMBCS_18,
       
   114     UCNV_LMBCS_19,
       
   115     UCNV_LMBCS_LAST = UCNV_LMBCS_19,
       
   116     UCNV_HZ,
       
   117     UCNV_SCSU,
       
   118     UCNV_ISCII,
       
   119     UCNV_US_ASCII,
       
   120     UCNV_UTF7,
       
   121     UCNV_BOCU1,
       
   122     UCNV_UTF16,
       
   123     UCNV_UTF32,
       
   124     UCNV_CESU8,
       
   125     UCNV_IMAP_MAILBOX,
       
   126 
       
   127     /* Number of converter types for which we have conversion routines. */
       
   128     UCNV_NUMBER_OF_SUPPORTED_CONVERTER_TYPES
       
   129 
       
   130 } UConverterType;
       
   131 
       
   132 /**
       
   133  * Enum for specifying which platform a converter ID refers to.
       
   134  * The use of platform/CCSID is not recommended. See ucnv_openCCSID().
       
   135  *
       
   136  * @see ucnv_getPlatform
       
   137  * @see ucnv_openCCSID
       
   138  * @see ucnv_getCCSID
       
   139  * @stable ICU 2.0
       
   140  */
       
   141 typedef enum {
       
   142     UCNV_UNKNOWN = -1,
       
   143     UCNV_IBM = 0
       
   144 } UConverterPlatform;
       
   145 
       
   146 /**
       
   147  * Function pointer for error callback in the codepage to unicode direction.
       
   148  * Called when an error has occured in conversion to unicode, or on open/close of the callback (see reason).
       
   149  * @param context Pointer to the callback's private data
       
   150  * @param args Information about the conversion in progress
       
   151  * @param codeUnits Points to 'length' bytes of the concerned codepage sequence
       
   152  * @param length Size (in bytes) of the concerned codepage sequence
       
   153  * @param reason Defines the reason the callback was invoked
       
   154  * @see ucnv_setToUCallBack
       
   155  * @see UConverterToUnicodeArgs
       
   156  * @stable ICU 2.0
       
   157  */
       
   158 typedef void (U_EXPORT2 *UConverterToUCallback) (
       
   159                   const void* context,
       
   160                   UConverterToUnicodeArgs *args,
       
   161                   const char *codeUnits,
       
   162                   int32_t length,
       
   163                   UConverterCallbackReason reason,
       
   164                   UErrorCode *);
       
   165 
       
   166 /**
       
   167  * Function pointer for error callback in the unicode to codepage direction.
       
   168  * Called when an error has occured in conversion from unicode, or on open/close of the callback (see reason).
       
   169  * @param context Pointer to the callback's private data
       
   170  * @param args Information about the conversion in progress
       
   171  * @param codeUnits Points to 'length' UChars of the concerned Unicode sequence
       
   172  * @param length Size (in bytes) of the concerned codepage sequence
       
   173  * @param codePoint Single UChar32 (UTF-32) containing the concerend Unicode codepoint.
       
   174  * @param reason Defines the reason the callback was invoked
       
   175  * @see ucnv_setFromUCallBack
       
   176  * @stable ICU 2.0
       
   177  */
       
   178 typedef void (U_EXPORT2 *UConverterFromUCallback) (
       
   179                     const void* context,
       
   180                     UConverterFromUnicodeArgs *args,
       
   181                     const UChar* codeUnits,
       
   182                     int32_t length,
       
   183                     UChar32 codePoint,
       
   184                     UConverterCallbackReason reason,
       
   185                     UErrorCode *);
       
   186 
       
   187 U_CDECL_END
       
   188 
       
   189 /**
       
   190  * Character that separates converter names from options and options from each other.
       
   191  * @see ucnv_open
       
   192  * @stable ICU 2.0
       
   193  */
       
   194 #define UCNV_OPTION_SEP_CHAR ','
       
   195 
       
   196 /**
       
   197  * String version of UCNV_OPTION_SEP_CHAR. 
       
   198  * @see ucnv_open
       
   199  * @stable ICU 2.0
       
   200  */
       
   201 #define UCNV_OPTION_SEP_STRING ","
       
   202 
       
   203 /**
       
   204  * Character that separates a converter option from its value.
       
   205  * @see ucnv_open
       
   206  * @stable ICU 2.0
       
   207  */
       
   208 #define UCNV_VALUE_SEP_CHAR '='
       
   209 
       
   210 /**
       
   211  * String version of UCNV_VALUE_SEP_CHAR. 
       
   212  * @see ucnv_open
       
   213  * @stable ICU 2.0
       
   214  */
       
   215 #define UCNV_VALUE_SEP_STRING "="
       
   216 
       
   217 /**
       
   218  * Converter option for specifying a locale.
       
   219  * For example, ucnv_open("SCSU,locale=ja", &errorCode);
       
   220  * See convrtrs.txt.
       
   221  *
       
   222  * @see ucnv_open
       
   223  * @stable ICU 2.0
       
   224  */
       
   225 #define UCNV_LOCALE_OPTION_STRING ",locale="
       
   226 
       
   227 /**
       
   228  * Converter option for specifying a version selector (0..9) for some converters.
       
   229  * For example, ucnv_open("UTF-7,version=1", &errorCode);
       
   230  * See convrtrs.txt.
       
   231  *
       
   232  * @see ucnv_open
       
   233  * @stable ICU 2.4
       
   234  */
       
   235 #define UCNV_VERSION_OPTION_STRING ",version="
       
   236 
       
   237 /**
       
   238  * Converter option for EBCDIC SBCS or mixed-SBCS/DBCS (stateful) codepages.
       
   239  * Swaps Unicode mappings for EBCDIC LF and NL codes, as used on
       
   240  * S/390 (z/OS) Unix System Services (Open Edition).
       
   241  * For example, ucnv_open("ibm-1047,swaplfnl", &errorCode);
       
   242  * See convrtrs.txt.
       
   243  *
       
   244  * @see ucnv_open
       
   245  * @stable ICU 2.4
       
   246  */
       
   247 #define UCNV_SWAP_LFNL_OPTION_STRING ",swaplfnl"
       
   248 
       
   249 /**
       
   250  * Do a fuzzy compare of a two converter/alias names.  The comparison
       
   251  * is case-insensitive.  It also ignores the characters '-', '_', and
       
   252  * ' ' (dash, underscore, and space).  Thus the strings "UTF-8",
       
   253  * "utf_8", and "Utf 8" are exactly equivalent.
       
   254  * 
       
   255  * @param name1 a converter name or alias, zero-terminated
       
   256  * @param name2 a converter name or alias, zero-terminated
       
   257  * @return 0 if the names match, or a negative value if the name1
       
   258  * lexically precedes name2, or a positive value if the name1
       
   259  * lexically follows name2.
       
   260  * @stable ICU 2.0
       
   261  */
       
   262 U_STABLE int U_EXPORT2
       
   263 ucnv_compareNames(const char *name1, const char *name2);
       
   264 
       
   265 
       
   266 /**
       
   267  * Creates a UConverter object with the names specified as a C string.
       
   268  * The actual name will be resolved with the alias file
       
   269  * using a case-insensitive string comparison that ignores
       
   270  * the delimiters '-', '_', and ' ' (dash, underscore, and space).
       
   271  * E.g., the names "UTF8", "utf-8", and "Utf 8" are all equivalent.
       
   272  * If <code>NULL</code> is passed for the converter name, it will create one with the
       
   273  * getDefaultName return value.
       
   274  *
       
   275  * <p>A converter name for ICU 1.5 and above may contain options
       
   276  * like a locale specification to control the specific behavior of
       
   277  * the newly instantiated converter.
       
   278  * The meaning of the options depends on the particular converter.
       
   279  * If an option is not defined for or recognized by a given converter, then it is ignored.</p>
       
   280  *
       
   281  * <p>Options are appended to the converter name string, with a
       
   282  * <code>UCNV_OPTION_SEP_CHAR</code> between the name and the first option and
       
   283  * also between adjacent options.</p>
       
   284  *
       
   285  * <p>If the alias is ambiguous, then the preferred converter is used
       
   286  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.</p>
       
   287  *
       
   288  * <p>The conversion behavior and names can vary between platforms. ICU may
       
   289  * convert some characters differently from other platforms. Details on this topic
       
   290  * are in the <a href="http://oss.software.ibm.com/icu/userguide/conversion.html">User's
       
   291  * Guide</a>.</p>
       
   292  *
       
   293  * @param converterName Name of the uconv table, may have options appended
       
   294  * @param err outgoing error status <TT>U_MEMORY_ALLOCATION_ERROR, U_FILE_ACCESS_ERROR</TT>
       
   295  * @return the created Unicode converter object, or <TT>NULL</TT> if an error occured
       
   296  * @see ucnv_openU
       
   297  * @see ucnv_openCCSID
       
   298  * @see ucnv_close
       
   299  * @stable ICU 2.0
       
   300  */
       
   301 U_STABLE UConverter* U_EXPORT2 
       
   302 ucnv_open(const char *converterName, UErrorCode *err);
       
   303 
       
   304 
       
   305 /**
       
   306  * Creates a Unicode converter with the names specified as unicode string. 
       
   307  * The name should be limited to the ASCII-7 alphanumerics range.
       
   308  * The actual name will be resolved with the alias file
       
   309  * using a case-insensitive string comparison that ignores
       
   310  * the delimiters '-', '_', and ' ' (dash, underscore, and space).
       
   311  * E.g., the names "UTF8", "utf-8", and "Utf 8" are all equivalent.
       
   312  * If <TT>NULL</TT> is passed for the converter name, it will create 
       
   313  * one with the ucnv_getDefaultName() return value.
       
   314  * If the alias is ambiguous, then the preferred converter is used
       
   315  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
       
   316  * @param name : name of the uconv table in a zero terminated 
       
   317  *        Unicode string
       
   318  * @param err outgoing error status <TT>U_MEMORY_ALLOCATION_ERROR, 
       
   319  *        U_FILE_ACCESS_ERROR</TT>
       
   320  * @return the created Unicode converter object, or <TT>NULL</TT> if an 
       
   321  *        error occured
       
   322  * @see ucnv_open
       
   323  * @see ucnv_openCCSID
       
   324  * @see ucnv_close
       
   325  * @see ucnv_getDefaultName
       
   326  * @stable ICU 2.0
       
   327  */
       
   328 U_STABLE UConverter* U_EXPORT2 
       
   329 ucnv_openU(const UChar *name,
       
   330            UErrorCode *err);
       
   331 
       
   332 /**
       
   333  * Creates a UConverter object from a CCSID number and platform pair.
       
   334  * Note that the usefulness of this function is limited to platforms with numeric
       
   335  * encoding IDs. Only IBM and Microsoft platforms use numeric (16-bit) identifiers for
       
   336  * encodings.
       
   337  *
       
   338  * In addition, IBM CCSIDs and Unicode conversion tables are not 1:1 related.
       
   339  * For many IBM CCSIDs there are multiple (up to six) Unicode conversion tables, and
       
   340  * for some Unicode conversion tables there are multiple CCSIDs.
       
   341  * Some "alternate" Unicode conversion tables are provided by the
       
   342  * IBM CDRA conversion table registry.
       
   343  * The most prominent example of a systematic modification of conversion tables that is
       
   344  * not provided in the form of conversion table files in the repository is
       
   345  * that S/390 Unix System Services swaps the codes for Line Feed and New Line in all
       
   346  * EBCDIC codepages, which requires such a swap in the Unicode conversion tables as well.
       
   347  *
       
   348  * Only IBM default conversion tables are accessible with ucnv_openCCSID().
       
   349  * ucnv_getCCSID() will return the same CCSID for all conversion tables that are associated
       
   350  * with that CCSID.
       
   351  *
       
   352  * Currently, the only "platform" supported in the ICU converter API is UCNV_IBM.
       
   353  *
       
   354  * In summary, the use of CCSIDs and the associated API functions is not recommended.
       
   355  *
       
   356  * In order to open a converter with the default IBM CDRA Unicode conversion table,
       
   357  * you can use this function or use the prefix "ibm-":
       
   358  * \code
       
   359  *     char name[20];
       
   360  *     sprintf(name, "ibm-%hu", ccsid);
       
   361  *     cnv=ucnv_open(name, &errorCode);
       
   362  * \endcode
       
   363  *
       
   364  * In order to open a converter with the IBM S/390 Unix System Services variant
       
   365  * of a Unicode/EBCDIC conversion table,
       
   366  * you can use the prefix "ibm-" together with the option string UCNV_SWAP_LFNL_OPTION_STRING:
       
   367  * \code
       
   368  *     char name[20];
       
   369  *     sprintf(name, "ibm-%hu" UCNV_SWAP_LFNL_OPTION_STRING, ccsid);
       
   370  *     cnv=ucnv_open(name, &errorCode);
       
   371  * \endcode
       
   372  *
       
   373  * In order to open a converter from a Microsoft codepage number, use the prefix "cp":
       
   374  * \code
       
   375  *     char name[20];
       
   376  *     sprintf(name, "cp%hu", codepageID);
       
   377  *     cnv=ucnv_open(name, &errorCode);
       
   378  * \endcode
       
   379  *
       
   380  * If the alias is ambiguous, then the preferred converter is used
       
   381  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
       
   382  *
       
   383  * @param codepage codepage number to create
       
   384  * @param platform the platform in which the codepage number exists
       
   385  * @param err error status <TT>U_MEMORY_ALLOCATION_ERROR, U_FILE_ACCESS_ERROR</TT>
       
   386  * @return the created Unicode converter object, or <TT>NULL</TT> if an error
       
   387  *   occured.
       
   388  * @see ucnv_open
       
   389  * @see ucnv_openU
       
   390  * @see ucnv_close
       
   391  * @see ucnv_getCCSID
       
   392  * @see ucnv_getPlatform
       
   393  * @see UConverterPlatform
       
   394  * @stable ICU 2.0
       
   395  */
       
   396 U_STABLE UConverter* U_EXPORT2
       
   397 ucnv_openCCSID(int32_t codepage,
       
   398                UConverterPlatform platform,
       
   399                UErrorCode * err);
       
   400 
       
   401 /**
       
   402  * <p>Creates a UConverter object specified from a packageName and a converterName.</p>
       
   403  * 
       
   404  * <p>The packageName and converterName must point to an ICU udata object, as defined by
       
   405  *   <code> udata_open( packageName, "cnv", converterName, err) </code> or equivalent.
       
   406  * Typically, packageName will refer to a (.dat) file, or to a package registered with
       
   407  * udata_setAppData().</p>
       
   408  * 
       
   409  * <p>The name will NOT be looked up in the alias mechanism, nor will the converter be
       
   410  * stored in the converter cache or the alias table. The only way to open further converters
       
   411  * is call this function multiple times, or use the ucnv_safeClone() function to clone a 
       
   412  * 'master' converter.</p>
       
   413  *
       
   414  * <p>A future version of ICU may add alias table lookups and/or caching
       
   415  * to this function.</p>
       
   416  * 
       
   417  * <p>Example Use:
       
   418  *      <code>cnv = ucnv_openPackage("myapp", "myconverter", &err);</code>
       
   419  * </p>
       
   420  *
       
   421  * @param packageName name of the package (equivalent to 'path' in udata_open() call)
       
   422  * @param converterName name of the data item to be used, without suffix.
       
   423  * @param err outgoing error status <TT>U_MEMORY_ALLOCATION_ERROR, U_FILE_ACCESS_ERROR</TT>
       
   424  * @return the created Unicode converter object, or <TT>NULL</TT> if an error occured
       
   425  * @see udata_open
       
   426  * @see ucnv_open
       
   427  * @see ucnv_safeClone
       
   428  * @see ucnv_close
       
   429  * @stable ICU 2.2
       
   430  */
       
   431 U_STABLE UConverter* U_EXPORT2 
       
   432 ucnv_openPackage(const char *packageName, const char *converterName, UErrorCode *err);
       
   433 
       
   434 /**
       
   435  * Thread safe cloning operation
       
   436  * @param cnv converter to be cloned
       
   437  * @param stackBuffer user allocated space for the new clone. If NULL new memory will be allocated. 
       
   438  *  If buffer is not large enough, new memory will be allocated.
       
   439  *  Clients can use the U_CNV_SAFECLONE_BUFFERSIZE. This will probably be enough to avoid memory allocations.
       
   440  * @param pBufferSize pointer to size of allocated space. 
       
   441  *  If *pBufferSize == 0, a sufficient size for use in cloning will 
       
   442  *  be returned ('pre-flighting')
       
   443  *  If *pBufferSize is not enough for a stack-based safe clone, 
       
   444  *  new memory will be allocated.
       
   445  * @param status to indicate whether the operation went on smoothly or there were errors
       
   446  *  An informational status value, U_SAFECLONE_ALLOCATED_ERROR, is used if any allocations were necessary.
       
   447  * @return pointer to the new clone
       
   448  * @stable ICU 2.0
       
   449  */
       
   450 U_STABLE UConverter * U_EXPORT2 
       
   451 ucnv_safeClone(const UConverter *cnv, 
       
   452                void             *stackBuffer,
       
   453                int32_t          *pBufferSize, 
       
   454                UErrorCode       *status);
       
   455 
       
   456 /**
       
   457  * \def U_CNV_SAFECLONE_BUFFERSIZE
       
   458  * Definition of a buffer size that is designed to be large enough for
       
   459  * converters to be cloned with ucnv_safeClone().
       
   460  * @stable ICU 2.0
       
   461  */
       
   462 #define U_CNV_SAFECLONE_BUFFERSIZE  1024
       
   463 
       
   464 /**
       
   465  * Deletes the unicode converter and releases resources associated
       
   466  * with just this instance.
       
   467  * Does not free up shared converter tables.
       
   468  *
       
   469  * @param converter the converter object to be deleted
       
   470  * @see ucnv_open
       
   471  * @see ucnv_openU
       
   472  * @see ucnv_openCCSID
       
   473  * @stable ICU 2.0
       
   474  */
       
   475 U_STABLE void  U_EXPORT2
       
   476 ucnv_close(UConverter * converter);
       
   477 
       
   478 /**
       
   479  * Fills in the output parameter, subChars, with the substitution characters
       
   480  * as multiple bytes.
       
   481  *
       
   482  * @param converter the Unicode converter
       
   483  * @param subChars the subsitution characters
       
   484  * @param len on input the capacity of subChars, on output the number 
       
   485  * of bytes copied to it
       
   486  * @param  err the outgoing error status code.
       
   487  * If the substitution character array is too small, an
       
   488  * <TT>U_INDEX_OUTOFBOUNDS_ERROR</TT> will be returned.
       
   489  * @see ucnv_setSubstChars
       
   490  * @stable ICU 2.0
       
   491  */
       
   492 U_STABLE void U_EXPORT2
       
   493 ucnv_getSubstChars(const UConverter *converter,
       
   494                    char *subChars,
       
   495                    int8_t *len,
       
   496                    UErrorCode *err);
       
   497 
       
   498 /**
       
   499  * Sets the substitution chars when converting from unicode to a codepage. The
       
   500  * substitution is specified as a string of 1-4 bytes, and may contain
       
   501  *  <TT>NULL</TT> byte.
       
   502  * @param converter the Unicode converter
       
   503  * @param subChars the substitution character byte sequence we want set
       
   504  * @param len the number of bytes in subChars
       
   505  * @param err the error status code.  <TT>U_INDEX_OUTOFBOUNDS_ERROR </TT> if
       
   506  * len is bigger than the maximum number of bytes allowed in subchars
       
   507  * @see ucnv_getSubstChars
       
   508  * @stable ICU 2.0
       
   509  */
       
   510 U_STABLE void U_EXPORT2
       
   511 ucnv_setSubstChars(UConverter *converter,
       
   512                    const char *subChars,
       
   513                    int8_t len,
       
   514                    UErrorCode *err);
       
   515 
       
   516 /**
       
   517  * Fills in the output parameter, errBytes, with the error characters from the
       
   518  * last failing conversion.
       
   519  *
       
   520  * @param converter the Unicode converter
       
   521  * @param errBytes the codepage bytes which were in error
       
   522  * @param len on input the capacity of errBytes, on output the number of
       
   523  *  bytes which were copied to it
       
   524  * @param err the error status code.
       
   525  * If the substitution character array is too small, an
       
   526  * <TT>U_INDEX_OUTOFBOUNDS_ERROR</TT> will be returned.
       
   527  * @stable ICU 2.0
       
   528  */
       
   529 U_STABLE void U_EXPORT2
       
   530 ucnv_getInvalidChars(const UConverter *converter,
       
   531                      char *errBytes,
       
   532                      int8_t *len,
       
   533                      UErrorCode *err);
       
   534 
       
   535 /**
       
   536  * Fills in the output parameter, errChars, with the error characters from the
       
   537  * last failing conversion.
       
   538  *
       
   539  * @param converter the Unicode converter
       
   540  * @param errUChars the UChars which were in error
       
   541  * @param len on input the capacity of errUChars, on output the number of 
       
   542  *  UChars which were copied to it
       
   543  * @param err the error status code.
       
   544  * If the substitution character array is too small, an
       
   545  * <TT>U_INDEX_OUTOFBOUNDS_ERROR</TT> will be returned.
       
   546  * @stable ICU 2.0
       
   547  */
       
   548 U_STABLE void U_EXPORT2
       
   549 ucnv_getInvalidUChars(const UConverter *converter,
       
   550                       UChar *errUChars,
       
   551                       int8_t *len,
       
   552                       UErrorCode *err);
       
   553 
       
   554 /**
       
   555  * Resets the state of a converter to the default state. This is used
       
   556  * in the case of an error, to restart a conversion from a known default state.
       
   557  * It will also empty the internal output buffers.
       
   558  * @param converter the Unicode converter
       
   559  * @stable ICU 2.0
       
   560  */
       
   561 U_STABLE void U_EXPORT2
       
   562 ucnv_reset(UConverter *converter);
       
   563 
       
   564 /**
       
   565  * Resets the to-Unicode part of a converter state to the default state.
       
   566  * This is used in the case of an error to restart a conversion to
       
   567  * Unicode to a known default state. It will also empty the internal
       
   568  * output buffers used for the conversion to Unicode codepoints.
       
   569  * @param converter the Unicode converter
       
   570  * @stable ICU 2.0
       
   571  */
       
   572 U_STABLE void U_EXPORT2 
       
   573 ucnv_resetToUnicode(UConverter *converter);
       
   574 
       
   575 /**
       
   576  * Resets the from-Unicode part of a converter state to the default state.
       
   577  * This is used in the case of an error to restart a conversion from
       
   578  * Unicode to a known default state. It will also empty the internal output
       
   579  * buffers used for the conversion from Unicode codepoints.
       
   580  * @param converter the Unicode converter
       
   581  * @stable ICU 2.0
       
   582  */
       
   583 U_STABLE void U_EXPORT2 
       
   584 ucnv_resetFromUnicode(UConverter *converter);
       
   585 
       
   586 /**
       
   587  * Returns the maximum number of bytes that are output per UChar in conversion
       
   588  * from Unicode using this converter.
       
   589  * The returned number can be used with UCNV_GET_MAX_BYTES_FOR_STRING
       
   590  * to calculate the size of a target buffer for conversion from Unicode.
       
   591  *
       
   592  * Note: Before ICU 2.8, this function did not return reliable numbers for
       
   593  * some stateful converters (EBCDIC_STATEFUL, ISO-2022) and LMBCS.
       
   594  *
       
   595  * This number may not be the same as the maximum number of bytes per
       
   596  * "conversion unit". In other words, it may not be the intuitively expected
       
   597  * number of bytes per character that would be published for a charset,
       
   598  * and may not fulfill any other purpose than the allocation of an output
       
   599  * buffer of guaranteed sufficient size for a given input length and converter.
       
   600  *
       
   601  * Examples for special cases that are taken into account:
       
   602  * - Supplementary code points may convert to more bytes than BMP code points.
       
   603  *   This function returns bytes per UChar (UTF-16 code unit), not per
       
   604  *   Unicode code point, for efficient buffer allocation.
       
   605  * - State-shifting output (SI/SO, escapes, etc.) from stateful converters.
       
   606  * - When m input UChars are converted to n output bytes, then the maximum m/n
       
   607  *   is taken into account.
       
   608  *
       
   609  * The number returned here does not take into account
       
   610  * (see UCNV_GET_MAX_BYTES_FOR_STRING):
       
   611  * - callbacks which output more than one charset character sequence per call,
       
   612  *   like escape callbacks
       
   613  * - initial and final non-character bytes that are output by some converters
       
   614  *   (automatic BOMs, initial escape sequence, final SI, etc.)
       
   615  *
       
   616  * Examples for returned values:
       
   617  * - SBCS charsets: 1
       
   618  * - Shift-JIS: 2
       
   619  * - UTF-16: 2 (2 per BMP, 4 per surrogate _pair_, BOM not counted)
       
   620  * - UTF-8: 3 (3 per BMP, 4 per surrogate _pair_)
       
   621  * - EBCDIC_STATEFUL (EBCDIC mixed SBCS/DBCS): 3 (SO + DBCS)
       
   622  * - ISO-2022: 3 (always outputs UTF-8)
       
   623  * - ISO-2022-JP: 6 (4-byte escape sequences + DBCS)
       
   624  * - ISO-2022-CN: 8 (4-byte designator sequences + 2-byte SS2/SS3 + DBCS)
       
   625  *
       
   626  * @param converter The Unicode converter.
       
   627  * @return The maximum number of bytes per UChar that are output by ucnv_fromUnicode(),
       
   628  *         to be used together with UCNV_GET_MAX_BYTES_FOR_STRING for buffer allocation.
       
   629  *
       
   630  * @see UCNV_GET_MAX_BYTES_FOR_STRING
       
   631  * @see ucnv_getMinCharSize
       
   632  * @stable ICU 2.0
       
   633  */
       
   634 U_STABLE int8_t U_EXPORT2
       
   635 ucnv_getMaxCharSize(const UConverter *converter);
       
   636 
       
   637 #ifndef U_HIDE_DRAFT_API
       
   638 
       
   639 /**
       
   640  * Calculates the size of a buffer for conversion from Unicode to a charset.
       
   641  * The calculated size is guaranteed to be sufficient for this conversion.
       
   642  *
       
   643  * It takes into account initial and final non-character bytes that are output
       
   644  * by some converters.
       
   645  * It does not take into account callbacks which output more than one charset
       
   646  * character sequence per call, like escape callbacks.
       
   647  * The default (substitution) callback only outputs one charset character sequence.
       
   648  *
       
   649  * @param length Number of UChars to be converted.
       
   650  * @param maxCharSize Return value from ucnv_getMaxCharSize() for the converter
       
   651  *                    that will be used.
       
   652  * @return Size of a buffer that will be large enough to hold the output bytes of
       
   653  *         converting length UChars with the converter that returned the maxCharSize.
       
   654  *
       
   655  * @see ucnv_getMaxCharSize
       
   656  * @draft ICU 2.8
       
   657  */
       
   658 #define UCNV_GET_MAX_BYTES_FOR_STRING(length, maxCharSize) \
       
   659      (((int32_t)(length)+10)*(int32_t)(maxCharSize))
       
   660 
       
   661 #endif /*U_HIDE_DRAFT_API*/
       
   662 
       
   663 /**
       
   664  * Returns the minimum byte length for characters in this codepage. 
       
   665  * This is usually either 1 or 2.
       
   666  * @param converter the Unicode converter
       
   667  * @return the minimum number of bytes allowed by this particular converter
       
   668  * @see ucnv_getMaxCharSize
       
   669  * @stable ICU 2.0
       
   670  */
       
   671 U_STABLE int8_t U_EXPORT2
       
   672 ucnv_getMinCharSize(const UConverter *converter);
       
   673 
       
   674 /**
       
   675  * Returns the display name of the converter passed in based on the Locale 
       
   676  * passed in. If the locale contains no display name, the internal ASCII
       
   677  * name will be filled in.
       
   678  *
       
   679  * @param converter the Unicode converter.
       
   680  * @param displayLocale is the specific Locale we want to localised for
       
   681  * @param displayName user provided buffer to be filled in
       
   682  * @param displayNameCapacity size of displayName Buffer
       
   683  * @param err error status code
       
   684  * @return displayNameLength number of UChar needed in displayName
       
   685  * @see ucnv_getName
       
   686  * @stable ICU 2.0
       
   687  */
       
   688 U_STABLE int32_t U_EXPORT2
       
   689 ucnv_getDisplayName(const UConverter *converter,
       
   690                     const char *displayLocale,
       
   691                     UChar *displayName,
       
   692                     int32_t displayNameCapacity,
       
   693                     UErrorCode *err);
       
   694 
       
   695 /**
       
   696  * Gets the internal, canonical name of the converter (zero-terminated).
       
   697  * The lifetime of the returned string will be that of the converter 
       
   698  * passed to this function.
       
   699  * @param converter the Unicode converter
       
   700  * @param err UErrorCode status
       
   701  * @return the internal name of the converter
       
   702  * @see ucnv_getDisplayName
       
   703  * @stable ICU 2.0
       
   704  */
       
   705 U_STABLE const char * U_EXPORT2 
       
   706 ucnv_getName(const UConverter *converter, UErrorCode *err);
       
   707 
       
   708 /**
       
   709  * Gets a codepage number associated with the converter. This is not guaranteed
       
   710  * to be the one used to create the converter. Some converters do not represent
       
   711  * platform registered codepages and return zero for the codepage number.
       
   712  * The error code fill-in parameter indicates if the codepage number
       
   713  * is available.
       
   714  * Does not check if the converter is <TT>NULL</TT> or if converter's data
       
   715  * table is <TT>NULL</TT>.
       
   716  *
       
   717  * Important: The use of CCSIDs is not recommended because it is limited
       
   718  * to only two platforms in principle and only one (UCNV_IBM) in the current
       
   719  * ICU converter API.
       
   720  * Also, CCSIDs are insufficient to identify IBM Unicode conversion tables precisely.
       
   721  * For more details see ucnv_openCCSID().
       
   722  *
       
   723  * @param converter the Unicode converter
       
   724  * @param err the error status code.
       
   725  * @return If any error occurrs, -1 will be returned otherwise, the codepage number
       
   726  * will be returned
       
   727  * @see ucnv_openCCSID
       
   728  * @see ucnv_getPlatform
       
   729  * @stable ICU 2.0
       
   730  */
       
   731 U_STABLE int32_t U_EXPORT2
       
   732 ucnv_getCCSID(const UConverter *converter,
       
   733               UErrorCode *err);
       
   734 
       
   735 /**
       
   736  * Gets a codepage platform associated with the converter. Currently, 
       
   737  * only <TT>UCNV_IBM</TT> will be returned.
       
   738  * Does not test if the converter is <TT>NULL</TT> or if converter's data 
       
   739  * table is <TT>NULL</TT>. 
       
   740  * @param converter the Unicode converter
       
   741  * @param err the error status code.
       
   742  * @return The codepage platform
       
   743  * @stable ICU 2.0
       
   744  */
       
   745 U_STABLE UConverterPlatform U_EXPORT2
       
   746 ucnv_getPlatform(const UConverter *converter,
       
   747                  UErrorCode *err);
       
   748 
       
   749 /**
       
   750  * Gets the type of the converter
       
   751  * e.g. SBCS, MBCS, DBCS, UTF8, UTF16_BE, UTF16_LE, ISO_2022, 
       
   752  * EBCDIC_STATEFUL, LATIN_1
       
   753  * @param converter a valid, opened converter
       
   754  * @return the type of the converter
       
   755  * @stable ICU 2.0
       
   756  */
       
   757 U_STABLE UConverterType U_EXPORT2
       
   758 ucnv_getType(const UConverter * converter);
       
   759 
       
   760 /**
       
   761  * Gets the "starter" (lead) bytes for converters of type MBCS.
       
   762  * Will fill in an <TT>U_ILLEGAL_ARGUMENT_ERROR</TT> if converter passed in
       
   763  * is not MBCS. Fills in an array of type UBool, with the value of the byte 
       
   764  * as offset to the array. For example, if (starters[0x20] == TRUE) at return,
       
   765  * it means that the byte 0x20 is a starter byte in this converter.
       
   766  * Context pointers are always owned by the caller.
       
   767  * 
       
   768  * @param converter a valid, opened converter of type MBCS
       
   769  * @param starters an array of size 256 to be filled in
       
   770  * @param err error status, <TT>U_ILLEGAL_ARGUMENT_ERROR</TT> if the 
       
   771  * converter is not a type which can return starters.
       
   772  * @see ucnv_getType
       
   773  * @stable ICU 2.0
       
   774  */
       
   775 U_STABLE void U_EXPORT2
       
   776 ucnv_getStarters(const UConverter* converter, 
       
   777                  UBool starters[256],
       
   778                  UErrorCode* err);
       
   779 
       
   780 
       
   781 /**
       
   782  * Selectors for Unicode sets that can be returned by ucnv_getUnicodeSet().
       
   783  * @see ucnv_getUnicodeSet
       
   784  * @stable ICU 2.6
       
   785  */
       
   786 typedef enum UConverterUnicodeSet {
       
   787     /** Select the set of roundtrippable Unicode code points. @stable ICU 2.6 */
       
   788     UCNV_ROUNDTRIP_SET,
       
   789     /** Number of UConverterUnicodeSet selectors. @stable ICU 2.6 */
       
   790     UCNV_SET_COUNT
       
   791 } UConverterUnicodeSet;
       
   792 
       
   793 
       
   794 /**
       
   795  * Returns the set of Unicode code points that can be converted by an ICU converter.
       
   796  *
       
   797  * The current implementation returns only one kind of set (UCNV_ROUNDTRIP_SET):
       
   798  * The set of all Unicode code points that can be roundtrip-converted
       
   799  * (converted without any data loss) with the converter.
       
   800  * This set will not include code points that have fallback mappings
       
   801  * or are only the result of reverse fallback mappings.
       
   802  * See UTR #22 "Character Mapping Markup Language"
       
   803  * at http://www.unicode.org/reports/tr22/
       
   804  *
       
   805  * This is useful for example for
       
   806  * - checking that a string or document can be roundtrip-converted with a converter,
       
   807  *   without/before actually performing the conversion
       
   808  * - testing if a converter can be used for text for typical text for a certain locale,
       
   809  *   by comparing its roundtrip set with the set of ExemplarCharacters from
       
   810  *   ICU's locale data or other sources
       
   811  *
       
   812  * In the future, there may be more UConverterUnicodeSet choices to select
       
   813  * sets with different properties.
       
   814  *
       
   815  * @param cnv The converter for which a set is requested.
       
   816  * @param setFillIn A valid USet *. It will be cleared by this function before
       
   817  *            the converter's specific set is filled into the USet.
       
   818  * @param whichSet A UConverterUnicodeSet selector;
       
   819  *              currently UCNV_ROUNDTRIP_SET is the only supported value.
       
   820  * @param pErrorCode ICU error code in/out parameter.
       
   821  *                   Must fulfill U_SUCCESS before the function call.
       
   822  *
       
   823  * @see UConverterUnicodeSet
       
   824  * @see uset_open
       
   825  * @see uset_close
       
   826  * @stable ICU 2.6
       
   827  */
       
   828 U_STABLE void U_EXPORT2
       
   829 ucnv_getUnicodeSet(const UConverter *cnv,
       
   830                    USet *setFillIn,
       
   831                    UConverterUnicodeSet whichSet,
       
   832                    UErrorCode *pErrorCode);
       
   833 
       
   834 /**
       
   835  * Gets the current calback function used by the converter when an illegal
       
   836  *  or invalid codepage sequence is found. 
       
   837  * Context pointers are always owned by the caller.
       
   838  *
       
   839  * @param converter the unicode converter
       
   840  * @param action fillin: returns the callback function pointer
       
   841  * @param context fillin: returns the callback's private void* context
       
   842  * @see ucnv_setToUCallBack
       
   843  * @stable ICU 2.0
       
   844  */
       
   845 U_STABLE void U_EXPORT2
       
   846 ucnv_getToUCallBack (const UConverter * converter,
       
   847                      UConverterToUCallback *action,
       
   848                      const void **context);
       
   849 
       
   850 /**
       
   851  * Gets the current callback function used by the converter when illegal 
       
   852  * or invalid Unicode sequence is found.
       
   853  * Context pointers are always owned by the caller.
       
   854  *
       
   855  * @param converter the unicode converter
       
   856  * @param action fillin: returns the callback function pointer
       
   857  * @param context fillin: returns the callback's private void* context
       
   858  * @see ucnv_setFromUCallBack
       
   859  * @stable ICU 2.0
       
   860  */
       
   861 U_STABLE void U_EXPORT2
       
   862 ucnv_getFromUCallBack (const UConverter * converter,
       
   863                        UConverterFromUCallback *action,
       
   864                        const void **context);
       
   865 
       
   866 /**
       
   867  * Changes the callback function used by the converter when
       
   868  * an illegal or invalid sequence is found.
       
   869  * Context pointers are always owned by the caller.
       
   870  * Predefined actions and contexts can be found in the ucnv_err.h header.
       
   871  *
       
   872  * @param converter the unicode converter
       
   873  * @param newAction the new callback function
       
   874  * @param newContext the new toUnicode callback context pointer. This can be NULL.
       
   875  * @param oldAction fillin: returns the old callback function pointer. This can be NULL.
       
   876  * @param oldContext fillin: returns the old callback's private void* context. This can be NULL.
       
   877  * @param err The error code status
       
   878  * @see ucnv_getToUCallBack
       
   879  * @stable ICU 2.0
       
   880  */
       
   881 U_STABLE void U_EXPORT2
       
   882 ucnv_setToUCallBack (UConverter * converter,
       
   883                      UConverterToUCallback newAction,
       
   884                      const void* newContext,
       
   885                      UConverterToUCallback *oldAction,
       
   886                      const void** oldContext,
       
   887                      UErrorCode * err);
       
   888 
       
   889 /**
       
   890  * Changes the current callback function used by the converter when
       
   891  * an illegal or invalid sequence is found.
       
   892  * Context pointers are always owned by the caller.
       
   893  * Predefined actions and contexts can be found in the ucnv_err.h header.
       
   894  *
       
   895  * @param converter the unicode converter
       
   896  * @param newAction the new callback function
       
   897  * @param newContext the new fromUnicode callback context pointer. This can be NULL.
       
   898  * @param oldAction fillin: returns the old callback function pointer. This can be NULL.
       
   899  * @param oldContext fillin: returns the old callback's private void* context. This can be NULL.
       
   900  * @param err The error code status
       
   901  * @see ucnv_getFromUCallBack
       
   902  * @stable ICU 2.0
       
   903  */
       
   904 U_STABLE void U_EXPORT2
       
   905 ucnv_setFromUCallBack (UConverter * converter,
       
   906                        UConverterFromUCallback newAction,
       
   907                        const void *newContext,
       
   908                        UConverterFromUCallback *oldAction,
       
   909                        const void **oldContext,
       
   910                        UErrorCode * err);
       
   911 
       
   912 /**
       
   913  * Converts an array of unicode characters to an array of codepage
       
   914  * characters. This function is optimized for converting a continuous
       
   915  * stream of data in buffer-sized chunks, where the entire source and
       
   916  * target does not fit in available buffers.
       
   917  * 
       
   918  * The source pointer is an in/out parameter. It starts out pointing where the 
       
   919  * conversion is to begin, and ends up pointing after the last UChar consumed. 
       
   920  * 
       
   921  * Target similarly starts out pointer at the first available byte in the output
       
   922  * buffer, and ends up pointing after the last byte written to the output.
       
   923  * 
       
   924  * The converter always attempts to consume the entire source buffer, unless 
       
   925  * (1.) the target buffer is full, or (2.) a failing error is returned from the
       
   926  * current callback function.  When a successful error status has been
       
   927  * returned, it means that all of the source buffer has been
       
   928  *  consumed. At that point, the caller should reset the source and
       
   929  *  sourceLimit pointers to point to the next chunk.
       
   930  * 
       
   931  * At the end of the stream (flush==TRUE), the input is completely consumed
       
   932  * when *source==sourceLimit and no error code is set.
       
   933  * The converter object is then automatically reset by this function.
       
   934  * (This means that a converter need not be reset explicitly between data
       
   935  * streams if it finishes the previous stream without errors.)
       
   936  * 
       
   937  * This is a <I>stateful</I> conversion. Additionally, even when all source data has
       
   938  * been consumed, some data may be in the converters' internal state.
       
   939  * Call this function repeatedly, updating the target pointers with
       
   940  * the next empty chunk of target in case of a
       
   941  * <TT>U_BUFFER_OVERFLOW_ERROR</TT>, and updating the source  pointers
       
   942  *  with the next chunk of source when a successful error status is
       
   943  * returned, until there are no more chunks of source data.
       
   944  * @param converter the Unicode converter
       
   945  * @param target I/O parameter. Input : Points to the beginning of the buffer to copy
       
   946  *  codepage characters to. Output : points to after the last codepage character copied
       
   947  *  to <TT>target</TT>.
       
   948  * @param targetLimit the pointer just after last of the <TT>target</TT> buffer
       
   949  * @param source I/O parameter, pointer to pointer to the source Unicode character buffer. 
       
   950  * @param sourceLimit the pointer just after the last of the source buffer
       
   951  * @param offsets if NULL is passed, nothing will happen to it, otherwise it needs to have the same number
       
   952  * of allocated cells as <TT>target</TT>. Will fill in offsets from target to source pointer
       
   953  * e.g: <TT>offsets[3]</TT> is equal to 6, it means that the <TT>target[3]</TT> was a result of transcoding <TT>source[6]</TT>
       
   954  * For output data carried across calls, and other data without a specific source character
       
   955  * (such as from escape sequences or callbacks)  -1 will be placed for offsets. 
       
   956  * @param flush set to <TT>TRUE</TT> if the current source buffer is the last available
       
   957  * chunk of the source, <TT>FALSE</TT> otherwise. Note that if a failing status is returned,
       
   958  * this function may have to be called multiple times with flush set to <TT>TRUE</TT> until
       
   959  * the source buffer is consumed.
       
   960  * @param err the error status.  <TT>U_ILLEGAL_ARGUMENT_ERROR</TT> will be set if the
       
   961  * converter is <TT>NULL</TT>.
       
   962  * <code>U_BUFFER_OVERFLOW_ERROR</code> will be set if the target is full and there is 
       
   963  * still data to be written to the target.
       
   964  * @see ucnv_fromUChars
       
   965  * @see ucnv_convert
       
   966  * @see ucnv_getMinCharSize
       
   967  * @see ucnv_setToUCallBack
       
   968  * @stable ICU 2.0
       
   969  */
       
   970 U_STABLE void U_EXPORT2 
       
   971 ucnv_fromUnicode (UConverter * converter,
       
   972                   char **target,
       
   973                   const char *targetLimit,
       
   974                   const UChar ** source,
       
   975                   const UChar * sourceLimit,
       
   976                   int32_t* offsets,
       
   977                   UBool flush,
       
   978                   UErrorCode * err);
       
   979 
       
   980 /**
       
   981  * Converts a buffer of codepage bytes into an array of unicode UChars
       
   982  * characters. This function is optimized for converting a continuous
       
   983  * stream of data in buffer-sized chunks, where the entire source and
       
   984  * target does not fit in available buffers.
       
   985  * 
       
   986  * The source pointer is an in/out parameter. It starts out pointing where the 
       
   987  * conversion is to begin, and ends up pointing after the last byte of source consumed. 
       
   988  * 
       
   989  * Target similarly starts out pointer at the first available UChar in the output
       
   990  * buffer, and ends up pointing after the last UChar written to the output. 
       
   991  * It does NOT necessarily keep UChar sequences together.
       
   992  * 
       
   993  * The converter always attempts to consume the entire source buffer, unless 
       
   994  * (1.) the target buffer is full, or (2.) a failing error is returned from the
       
   995  * current callback function.  When a successful error status has been
       
   996  * returned, it means that all of the source buffer has been
       
   997  *  consumed. At that point, the caller should reset the source and
       
   998  *  sourceLimit pointers to point to the next chunk.
       
   999  *
       
  1000  * At the end of the stream (flush==TRUE), the input is completely consumed
       
  1001  * when *source==sourceLimit and no error code is set
       
  1002  * The converter object is then automatically reset by this function.
       
  1003  * (This means that a converter need not be reset explicitly between data
       
  1004  * streams if it finishes the previous stream without errors.)
       
  1005  * 
       
  1006  * This is a <I>stateful</I> conversion. Additionally, even when all source data has
       
  1007  * been consumed, some data may be in the converters' internal state.
       
  1008  * Call this function repeatedly, updating the target pointers with
       
  1009  * the next empty chunk of target in case of a
       
  1010  * <TT>U_BUFFER_OVERFLOW_ERROR</TT>, and updating the source  pointers
       
  1011  *  with the next chunk of source when a successful error status is
       
  1012  * returned, until there are no more chunks of source data.
       
  1013  * @param converter the Unicode converter
       
  1014  * @param target I/O parameter. Input : Points to the beginning of the buffer to copy
       
  1015  *  UChars into. Output : points to after the last UChar copied.
       
  1016  * @param targetLimit the pointer just after the end of the <TT>target</TT> buffer
       
  1017  * @param source I/O parameter, pointer to pointer to the source codepage buffer. 
       
  1018  * @param sourceLimit the pointer to the byte after the end of the source buffer
       
  1019  * @param offsets if NULL is passed, nothing will happen to it, otherwise it needs to have the same number
       
  1020  * of allocated cells as <TT>target</TT>. Will fill in offsets from target to source pointer
       
  1021  * e.g: <TT>offsets[3]</TT> is equal to 6, it means that the <TT>target[3]</TT> was a result of transcoding <TT>source[6]</TT>
       
  1022  * For output data carried across calls, and other data without a specific source character
       
  1023  * (such as from escape sequences or callbacks)  -1 will be placed for offsets. 
       
  1024  * @param flush set to <TT>TRUE</TT> if the current source buffer is the last available
       
  1025  * chunk of the source, <TT>FALSE</TT> otherwise. Note that if a failing status is returned,
       
  1026  * this function may have to be called multiple times with flush set to <TT>TRUE</TT> until
       
  1027  * the source buffer is consumed.
       
  1028  * @param err the error status.  <TT>U_ILLEGAL_ARGUMENT_ERROR</TT> will be set if the
       
  1029  * converter is <TT>NULL</TT>.
       
  1030  * <code>U_BUFFER_OVERFLOW_ERROR</code> will be set if the target is full and there is 
       
  1031  * still data to be written to the target. 
       
  1032  * @see ucnv_fromUChars
       
  1033  * @see ucnv_convert
       
  1034  * @see ucnv_getMinCharSize
       
  1035  * @see ucnv_setFromUCallBack
       
  1036  * @see ucnv_getNextUChar
       
  1037  * @stable ICU 2.0
       
  1038  */
       
  1039 U_STABLE void U_EXPORT2 
       
  1040 ucnv_toUnicode(UConverter *converter,
       
  1041                UChar **target,
       
  1042                const UChar *targetLimit,
       
  1043                const char **source,
       
  1044                const char *sourceLimit,
       
  1045                int32_t *offsets,
       
  1046                UBool flush,
       
  1047                UErrorCode *err);
       
  1048 
       
  1049 /**
       
  1050  * Convert the Unicode string into a codepage string using an existing UConverter.
       
  1051  * The output string is NUL-terminated if possible.
       
  1052  *
       
  1053  * This function is a more convenient but less powerful version of ucnv_fromUnicode().
       
  1054  * It is only useful for whole strings, not for streaming conversion.
       
  1055  *
       
  1056  * The maximum output buffer capacity required (barring output from callbacks) will be
       
  1057  * UCNV_GET_MAX_BYTES_FOR_STRING(srcLength, ucnv_getMaxCharSize(cnv)).
       
  1058  *
       
  1059  * @param cnv the converter object to be used (ucnv_resetFromUnicode() will be called)
       
  1060  * @param src the input Unicode string
       
  1061  * @param srcLength the input string length, or -1 if NUL-terminated
       
  1062  * @param dest destination string buffer, can be NULL if destCapacity==0
       
  1063  * @param destCapacity the number of chars available at dest
       
  1064  * @param pErrorCode normal ICU error code;
       
  1065  *                  common error codes that may be set by this function include
       
  1066  *                  U_BUFFER_OVERFLOW_ERROR, U_STRING_NOT_TERMINATED_WARNING,
       
  1067  *                  U_ILLEGAL_ARGUMENT_ERROR, and conversion errors
       
  1068  * @return the length of the output string, not counting the terminating NUL;
       
  1069  *         if the length is greater than destCapacity, then the string will not fit
       
  1070  *         and a buffer of the indicated length would need to be passed in
       
  1071  * @see ucnv_fromUnicode
       
  1072  * @see ucnv_convert
       
  1073  * @see UCNV_GET_MAX_BYTES_FOR_STRING
       
  1074  * @stable ICU 2.0
       
  1075  */
       
  1076 U_STABLE int32_t U_EXPORT2
       
  1077 ucnv_fromUChars(UConverter *cnv,
       
  1078                 char *dest, int32_t destCapacity,
       
  1079                 const UChar *src, int32_t srcLength,
       
  1080                 UErrorCode *pErrorCode);
       
  1081 
       
  1082 /**
       
  1083  * Convert the codepage string into a Unicode string using an existing UConverter.
       
  1084  * The output string is NUL-terminated if possible.
       
  1085  *
       
  1086  * This function is a more convenient but less powerful version of ucnv_toUnicode().
       
  1087  * It is only useful for whole strings, not for streaming conversion.
       
  1088  *
       
  1089  * The maximum output buffer capacity required (barring output from callbacks) will be
       
  1090  * 2*srcLength (each char may be converted into a surrogate pair).
       
  1091  *
       
  1092  * @param cnv the converter object to be used (ucnv_resetToUnicode() will be called)
       
  1093  * @param src the input codepage string
       
  1094  * @param srcLength the input string length, or -1 if NUL-terminated
       
  1095  * @param dest destination string buffer, can be NULL if destCapacity==0
       
  1096  * @param destCapacity the number of UChars available at dest
       
  1097  * @param pErrorCode normal ICU error code;
       
  1098  *                  common error codes that may be set by this function include
       
  1099  *                  U_BUFFER_OVERFLOW_ERROR, U_STRING_NOT_TERMINATED_WARNING,
       
  1100  *                  U_ILLEGAL_ARGUMENT_ERROR, and conversion errors
       
  1101  * @return the length of the output string, not counting the terminating NUL;
       
  1102  *         if the length is greater than destCapacity, then the string will not fit
       
  1103  *         and a buffer of the indicated length would need to be passed in
       
  1104  * @see ucnv_toUnicode
       
  1105  * @see ucnv_convert
       
  1106  * @stable ICU 2.0
       
  1107  */
       
  1108 U_STABLE int32_t U_EXPORT2
       
  1109 ucnv_toUChars(UConverter *cnv,
       
  1110               UChar *dest, int32_t destCapacity,
       
  1111               const char *src, int32_t srcLength,
       
  1112               UErrorCode *pErrorCode);
       
  1113 
       
  1114 /**
       
  1115  * Convert a codepage buffer into Unicode one character at a time.
       
  1116  * The input is completely consumed when the U_INDEX_OUTOFBOUNDS_ERROR is set.
       
  1117  *
       
  1118  * Advantage compared to ucnv_toUnicode() or ucnv_toUChars():
       
  1119  * - Faster for small amounts of data, for most converters, e.g.,
       
  1120  *   US-ASCII, ISO-8859-1, UTF-8/16/32, and most "normal" charsets.
       
  1121  *   (For complex converters, e.g., SCSU, UTF-7 and ISO 2022 variants,
       
  1122  *    it uses ucnv_toUnicode() internally.)
       
  1123  * - Convenient.
       
  1124  *
       
  1125  * Limitations compared to ucnv_toUnicode():
       
  1126  * - Always assumes flush=TRUE.
       
  1127  *   This makes ucnv_getNextUChar() unsuitable for "streaming" conversion,
       
  1128  *   that is, for where the input is supplied in multiple buffers,
       
  1129  *   because ucnv_getNextUChar() will assume the end of the input at the end
       
  1130  *   of the first buffer.
       
  1131  * - Does not provide offset output.
       
  1132  *
       
  1133  * It is possible to "mix" ucnv_getNextUChar() and ucnv_toUnicode() because
       
  1134  * ucnv_getNextUChar() uses the current state of the converter
       
  1135  * (unlike ucnv_toUChars() which always resets first).
       
  1136  * However, if ucnv_getNextUChar() is called after ucnv_toUnicode()
       
  1137  * stopped in the middle of a character sequence (with flush=FALSE),
       
  1138  * then ucnv_getNextUChar() will always use the slower ucnv_toUnicode()
       
  1139  * internally until the next character boundary.
       
  1140  * (This is new in ICU 2.6. In earlier releases, ucnv_getNextUChar() had to
       
  1141  * start at a character boundary.)
       
  1142  *
       
  1143  * Instead of using ucnv_getNextUChar(), it is recommended
       
  1144  * to convert using ucnv_toUnicode() or ucnv_toUChars()
       
  1145  * and then iterate over the text using U16_NEXT() or a UCharIterator (uiter.h)
       
  1146  * or a C++ CharacterIterator or similar.
       
  1147  * This allows streaming conversion and offset output, for example.
       
  1148  *
       
  1149  * <p>Handling of surrogate pairs and supplementary-plane code points:<br>
       
  1150  * There are two different kinds of codepages that provide mappings for surrogate characters:
       
  1151  * <ul>
       
  1152  *   <li>Codepages like UTF-8, UTF-32, and GB 18030 provide direct representations for Unicode
       
  1153  *       code points U+10000-U+10ffff as well as for single surrogates U+d800-U+dfff.
       
  1154  *       Each valid sequence will result in exactly one returned code point.
       
  1155  *       If a sequence results in a single surrogate, then that will be returned
       
  1156  *       by itself, even if a neighboring sequence encodes the matching surrogate.</li>
       
  1157  *   <li>Codepages like SCSU and LMBCS (and UTF-16) provide direct representations only for BMP code points
       
  1158  *       including surrogates. Code points in supplementary planes are represented with
       
  1159  *       two sequences, each encoding a surrogate.
       
  1160  *       For these codepages, matching pairs of surrogates will be combined into single
       
  1161  *       code points for returning from this function.
       
  1162  *       (Note that SCSU is actually a mix of these codepage types.)</li>
       
  1163  * </ul></p>
       
  1164  *
       
  1165  * @param converter an open UConverter
       
  1166  * @param source the address of a pointer to the codepage buffer, will be
       
  1167  *  updated to point after the bytes consumed in the conversion call.
       
  1168  * @param sourceLimit points to the end of the input buffer
       
  1169  * @param err fills in error status (see ucnv_toUnicode)
       
  1170  * <code>U_INDEX_OUTOFBOUNDS_ERROR</code> will be set if the input 
       
  1171  * is empty or does not convert to any output (e.g.: pure state-change 
       
  1172  * codes SI/SO, escape sequences for ISO 2022,
       
  1173  * or if the callback did not output anything, ...).
       
  1174  * This function will not set a <code>U_BUFFER_OVERFLOW_ERROR</code> because
       
  1175  *  the "buffer" is the return code. However, there might be subsequent output
       
  1176  *  stored in the converter object
       
  1177  * that will be returned in following calls to this function.
       
  1178  * @return a UChar32 resulting from the partial conversion of source
       
  1179  * @see ucnv_toUnicode
       
  1180  * @see ucnv_toUChars
       
  1181  * @see ucnv_convert
       
  1182  * @stable ICU 2.0
       
  1183  */
       
  1184 U_STABLE UChar32 U_EXPORT2
       
  1185 ucnv_getNextUChar(UConverter * converter,
       
  1186                   const char **source,
       
  1187                   const char * sourceLimit,
       
  1188                   UErrorCode * err);
       
  1189 
       
  1190 /**
       
  1191  * Convert from one external charset to another using two existing UConverters.
       
  1192  * Internally, two conversions - ucnv_toUnicode() and ucnv_fromUnicode() -
       
  1193  * are used, "pivoting" through 16-bit Unicode.
       
  1194  *
       
  1195  * There is a similar function, ucnv_convert(),
       
  1196  * which has the following limitations:
       
  1197  * - it takes charset names, not converter objects, so that
       
  1198  *   - two converters are opened for each call
       
  1199  *   - only single-string conversion is possible, not streaming operation
       
  1200  * - it does not provide enough information to find out,
       
  1201  *   in case of failure, whether the toUnicode or
       
  1202  *   the fromUnicode conversion failed
       
  1203  *
       
  1204  * By contrast, ucnv_convertEx()
       
  1205  * - takes UConverter parameters instead of charset names
       
  1206  * - fully exposes the pivot buffer for complete error handling
       
  1207  *
       
  1208  * ucnv_convertEx() also provides further convenience:
       
  1209  * - an option to reset the converters at the beginning
       
  1210  *   (if reset==TRUE, see parameters;
       
  1211  *    also sets *pivotTarget=*pivotSource=pivotStart)
       
  1212  * - allow NUL-terminated input
       
  1213  *   (only a single NUL byte, will not work for charsets with multi-byte NULs)
       
  1214  *   (if sourceLimit==NULL, see parameters)
       
  1215  * - terminate with a NUL on output
       
  1216  *   (only a single NUL byte, not useful for charsets with multi-byte NULs),
       
  1217  *   or set U_STRING_NOT_TERMINATED_WARNING if the output exactly fills
       
  1218  *   the target buffer
       
  1219  * - the pivot buffer can be provided internally;
       
  1220  *   in this case, the caller will not be able to get details about where an
       
  1221  *   error occurred
       
  1222  *   (if pivotStart==NULL, see below)
       
  1223  *
       
  1224  * The function returns when one of the following is true:
       
  1225  * - the entire source text has been converted successfully to the target buffer
       
  1226  * - a target buffer overflow occurred (U_BUFFER_OVERFLOW_ERROR)
       
  1227  * - a conversion error occurred
       
  1228  *   (other U_FAILURE(), see description of pErrorCode)
       
  1229  *
       
  1230  * Limitation compared to the direct use of
       
  1231  * ucnv_fromUnicode() and ucnv_toUnicode():
       
  1232  * ucnv_convertEx() does not provide offset information.
       
  1233  *
       
  1234  * Limitation compared to ucnv_fromUChars() and ucnv_toUChars():
       
  1235  * ucnv_convertEx() does not support preflighting directly.
       
  1236  *
       
  1237  * Sample code for converting a single string from
       
  1238  * one external charset to UTF-8, ignoring the location of errors:
       
  1239  *
       
  1240  * \code
       
  1241  * int32_t
       
  1242  * myToUTF8(UConverter *cnv,
       
  1243  *          const char *s, int32_t length,
       
  1244  *          char *u8, int32_t capacity,
       
  1245  *          UErrorCode *pErrorCode) {
       
  1246  *     UConverter *utf8Cnv;
       
  1247  *     char *target;
       
  1248  *
       
  1249  *     if(U_FAILURE(*pErrorCode)) {
       
  1250  *         return 0;
       
  1251  *     }
       
  1252  *
       
  1253  *     utf8Cnv=myGetCachedUTF8Converter(pErrorCode);
       
  1254  *     if(U_FAILURE(*pErrorCode)) {
       
  1255  *         return 0;
       
  1256  *     }
       
  1257  *
       
  1258  *     target=u8;
       
  1259  *     ucnv_convertEx(cnv, utf8Cnv,
       
  1260  *                    &target, u8+capacity,
       
  1261  *                    &s, length>=0 ? s+length : NULL,
       
  1262  *                    NULL, NULL, NULL, NULL,
       
  1263  *                    TRUE, TRUE,
       
  1264  *                    pErrorCode);
       
  1265  * 
       
  1266  *     myReleaseCachedUTF8Converter(utf8Cnv);
       
  1267  *
       
  1268  *     // return the output string length, but without preflighting
       
  1269  *     return (int32_t)(target-u8);
       
  1270  * }
       
  1271  * \endcode
       
  1272  *
       
  1273  * @param targetCnv     Output converter, used to convert from the UTF-16 pivot
       
  1274  *                      to the target using ucnv_fromUnicode().
       
  1275  * @param sourceCnv     Input converter, used to convert from the source to
       
  1276  *                      the UTF-16 pivot using ucnv_toUnicode().
       
  1277  * @param target        I/O parameter, same as for ucnv_fromUChars().
       
  1278  *                      Input: *target points to the beginning of the target buffer.
       
  1279  *                      Output: *target points to the first unit after the last char written.
       
  1280  * @param targetLimit   Pointer to the first unit after the target buffer.
       
  1281  * @param source        I/O parameter, same as for ucnv_toUChars().
       
  1282  *                      Input: *source points to the beginning of the source buffer.
       
  1283  *                      Output: *source points to the first unit after the last char read.
       
  1284  * @param sourceLimit   Pointer to the first unit after the source buffer.
       
  1285  * @param pivotStart    Pointer to the UTF-16 pivot buffer. If pivotStart==NULL,
       
  1286  *                      then an internal buffer is used and the other pivot
       
  1287  *                      arguments are ignored and can be NULL as well.
       
  1288  * @param pivotSource   I/O parameter, same as source in ucnv_fromUChars() for
       
  1289  *                      conversion from the pivot buffer to the target buffer.
       
  1290  * @param pivotTarget   I/O parameter, same as target in ucnv_toUChars() for
       
  1291  *                      conversion from the source buffer to the pivot buffer.
       
  1292  *                      It must be pivotStart<=*pivotSource<=*pivotTarget<=pivotLimit
       
  1293  *                      and pivotStart<pivotLimit (unless pivotStart==NULL).
       
  1294  * @param pivotLimit    Pointer to the first unit after the pivot buffer.
       
  1295  * @param reset         If TRUE, then ucnv_resetToUnicode(sourceCnv) and
       
  1296  *                      ucnv_resetFromUnicode(targetCnv) are called, and the
       
  1297  *                      pivot pointers are reset (*pivotTarget=*pivotSource=pivotStart).
       
  1298  * @param flush         If true, indicates the end of the input.
       
  1299  *                      Passed directly to ucnv_toUnicode(), and carried over to
       
  1300  *                      ucnv_fromUnicode() when the source is empty as well.
       
  1301  * @param pErrorCode    ICU error code in/out parameter.
       
  1302  *                      Must fulfill U_SUCCESS before the function call.
       
  1303  *                      U_BUFFER_OVERFLOW_ERROR always refers to the target buffer
       
  1304  *                      because overflows into the pivot buffer are handled internally.
       
  1305  *                      Other conversion errors are from the source-to-pivot
       
  1306  *                      conversion if *pivotSource==pivotStart, otherwise from
       
  1307  *                      the pivot-to-target conversion.
       
  1308  *
       
  1309  * @see ucnv_convert
       
  1310  * @see ucnv_fromAlgorithmic
       
  1311  * @see ucnv_toAlgorithmic
       
  1312  * @see ucnv_fromUnicode
       
  1313  * @see ucnv_toUnicode
       
  1314  * @see ucnv_fromUChars
       
  1315  * @see ucnv_toUChars
       
  1316  * @stable ICU 2.6
       
  1317  */
       
  1318 U_STABLE void U_EXPORT2
       
  1319 ucnv_convertEx(UConverter *targetCnv, UConverter *sourceCnv,
       
  1320                char **target, const char *targetLimit,
       
  1321                const char **source, const char *sourceLimit,
       
  1322                UChar *pivotStart, UChar **pivotSource,
       
  1323                UChar **pivotTarget, const UChar *pivotLimit,
       
  1324                UBool reset, UBool flush,
       
  1325                UErrorCode *pErrorCode);
       
  1326 
       
  1327 /**
       
  1328  * Convert from one external charset to another.
       
  1329  * Internally, two converters are opened according to the name arguments,
       
  1330  * then the text is converted to and from the 16-bit Unicode "pivot"
       
  1331  * using ucnv_convertEx(), then the converters are closed again.
       
  1332  *
       
  1333  * This is a convenience function, not an efficient way to convert a lot of text:
       
  1334  * ucnv_convert()
       
  1335  * - takes charset names, not converter objects, so that
       
  1336  *   - two converters are opened for each call
       
  1337  *   - only single-string conversion is possible, not streaming operation
       
  1338  * - does not provide enough information to find out,
       
  1339  *   in case of failure, whether the toUnicode or
       
  1340  *   the fromUnicode conversion failed
       
  1341  * - allows NUL-terminated input
       
  1342  *   (only a single NUL byte, will not work for charsets with multi-byte NULs)
       
  1343  *   (if sourceLength==-1, see parameters)
       
  1344  * - terminate with a NUL on output
       
  1345  *   (only a single NUL byte, not useful for charsets with multi-byte NULs),
       
  1346  *   or set U_STRING_NOT_TERMINATED_WARNING if the output exactly fills
       
  1347  *   the target buffer
       
  1348  * - a pivot buffer is provided internally
       
  1349  *
       
  1350  * The function returns when one of the following is true:
       
  1351  * - the entire source text has been converted successfully to the target buffer
       
  1352  *   and either the target buffer is terminated with a single NUL byte
       
  1353  *   or the error code is set to U_STRING_NOT_TERMINATED_WARNING
       
  1354  * - a target buffer overflow occurred (U_BUFFER_OVERFLOW_ERROR)
       
  1355  *   and the full output string length is returned ("preflighting")
       
  1356  * - a conversion error occurred
       
  1357  *   (other U_FAILURE(), see description of pErrorCode)
       
  1358  *
       
  1359  * @param toConverterName   The name of the converter that is used to convert
       
  1360  *                          from the UTF-16 pivot buffer to the target.
       
  1361  * @param fromConverterName The name of the converter that is used to convert
       
  1362  *                          from the source to the UTF-16 pivot buffer.
       
  1363  * @param target            Pointer to the output buffer.
       
  1364  * @param targetCapacity    Capacity of the target, in bytes.
       
  1365  * @param source            Pointer to the input buffer.
       
  1366  * @param sourceLength      Length of the input text, in bytes, or -1 for NUL-terminated input.
       
  1367  * @param pErrorCode        ICU error code in/out parameter.
       
  1368  *                          Must fulfill U_SUCCESS before the function call.
       
  1369  * @return Length of the complete output text in bytes, even if it exceeds the targetCapacity
       
  1370  *         and a U_BUFFER_OVERFLOW_ERROR is set.
       
  1371  *
       
  1372  * @see ucnv_convertEx
       
  1373  * @see ucnv_fromAlgorithmic
       
  1374  * @see ucnv_toAlgorithmic
       
  1375  * @see ucnv_fromUnicode
       
  1376  * @see ucnv_toUnicode
       
  1377  * @see ucnv_fromUChars
       
  1378  * @see ucnv_toUChars
       
  1379  * @see ucnv_getNextUChar
       
  1380  * @stable ICU 2.0
       
  1381  */
       
  1382 U_STABLE int32_t U_EXPORT2
       
  1383 ucnv_convert(const char *toConverterName,
       
  1384              const char *fromConverterName,
       
  1385              char *target,
       
  1386              int32_t targetCapacity,
       
  1387              const char *source,
       
  1388              int32_t sourceLength,
       
  1389              UErrorCode *pErrorCode);
       
  1390 
       
  1391 /**
       
  1392  * Convert from one external charset to another.
       
  1393  * Internally, the text is converted to and from the 16-bit Unicode "pivot"
       
  1394  * using ucnv_convertEx(). ucnv_toAlgorithmic() works exactly like ucnv_convert()
       
  1395  * except that the two converters need not be looked up and opened completely.
       
  1396  *
       
  1397  * The source-to-pivot conversion uses the cnv converter parameter.
       
  1398  * The pivot-to-target conversion uses a purely algorithmic converter
       
  1399  * according to the specified type, e.g., UCNV_UTF8 for a UTF-8 converter.
       
  1400  *
       
  1401  * Internally, the algorithmic converter is opened and closed for each
       
  1402  * function call, which is more efficient than using the public ucnv_open()
       
  1403  * but somewhat less efficient than only resetting an existing converter
       
  1404  * and using ucnv_convertEx().
       
  1405  *
       
  1406  * This function is more convenient than ucnv_convertEx() for single-string
       
  1407  * conversions, especially when "preflighting" is desired (returning the length
       
  1408  * of the complete output even if it does not fit into the target buffer;
       
  1409  * see the User Guide Strings chapter). See ucnv_convert() for details.
       
  1410  *
       
  1411  * @param algorithmicType   UConverterType constant identifying the desired target
       
  1412  *                          charset as a purely algorithmic converter.
       
  1413  *                          Those are converters for Unicode charsets like
       
  1414  *                          UTF-8, BOCU-1, SCSU, UTF-7, IMAP-mailbox-name, etc.,
       
  1415  *                          as well as US-ASCII and ISO-8859-1.
       
  1416  * @param cnv               The converter that is used to convert
       
  1417  *                          from the source to the UTF-16 pivot buffer.
       
  1418  * @param target            Pointer to the output buffer.
       
  1419  * @param targetCapacity    Capacity of the target, in bytes.
       
  1420  * @param source            Pointer to the input buffer.
       
  1421  * @param sourceLength      Length of the input text, in bytes
       
  1422  * @param pErrorCode        ICU error code in/out parameter.
       
  1423  *                          Must fulfill U_SUCCESS before the function call.
       
  1424  * @return Length of the complete output text in bytes, even if it exceeds the targetCapacity
       
  1425  *         and a U_BUFFER_OVERFLOW_ERROR is set.
       
  1426  *
       
  1427  * @see ucnv_fromAlgorithmic
       
  1428  * @see ucnv_convert
       
  1429  * @see ucnv_convertEx
       
  1430  * @see ucnv_fromUnicode
       
  1431  * @see ucnv_toUnicode
       
  1432  * @see ucnv_fromUChars
       
  1433  * @see ucnv_toUChars
       
  1434  * @stable ICU 2.6
       
  1435  */
       
  1436 U_STABLE int32_t U_EXPORT2
       
  1437 ucnv_toAlgorithmic(UConverterType algorithmicType,
       
  1438                    UConverter *cnv,
       
  1439                    char *target, int32_t targetCapacity,
       
  1440                    const char *source, int32_t sourceLength,
       
  1441                    UErrorCode *pErrorCode);
       
  1442 
       
  1443 /**
       
  1444  * Convert from one external charset to another.
       
  1445  * Internally, the text is converted to and from the 16-bit Unicode "pivot"
       
  1446  * using ucnv_convertEx(). ucnv_fromAlgorithmic() works exactly like ucnv_convert()
       
  1447  * except that the two converters need not be looked up and opened completely.
       
  1448  *
       
  1449  * The source-to-pivot conversion uses a purely algorithmic converter
       
  1450  * according to the specified type, e.g., UCNV_UTF8 for a UTF-8 converter.
       
  1451  * The pivot-to-target conversion uses the cnv converter parameter.
       
  1452  *
       
  1453  * Internally, the algorithmic converter is opened and closed for each
       
  1454  * function call, which is more efficient than using the public ucnv_open()
       
  1455  * but somewhat less efficient than only resetting an existing converter
       
  1456  * and using ucnv_convertEx().
       
  1457  *
       
  1458  * This function is more convenient than ucnv_convertEx() for single-string
       
  1459  * conversions, especially when "preflighting" is desired (returning the length
       
  1460  * of the complete output even if it does not fit into the target buffer;
       
  1461  * see the User Guide Strings chapter). See ucnv_convert() for details.
       
  1462  *
       
  1463  * @param cnv               The converter that is used to convert
       
  1464  *                          from the UTF-16 pivot buffer to the target.
       
  1465  * @param algorithmicType   UConverterType constant identifying the desired source
       
  1466  *                          charset as a purely algorithmic converter.
       
  1467  *                          Those are converters for Unicode charsets like
       
  1468  *                          UTF-8, BOCU-1, SCSU, UTF-7, IMAP-mailbox-name, etc.,
       
  1469  *                          as well as US-ASCII and ISO-8859-1.
       
  1470  * @param target            Pointer to the output buffer.
       
  1471  * @param targetCapacity    Capacity of the target, in bytes.
       
  1472  * @param source            Pointer to the input buffer.
       
  1473  * @param sourceLength      Length of the input text, in bytes
       
  1474  * @param pErrorCode        ICU error code in/out parameter.
       
  1475  *                          Must fulfill U_SUCCESS before the function call.
       
  1476  * @return Length of the complete output text in bytes, even if it exceeds the targetCapacity
       
  1477  *         and a U_BUFFER_OVERFLOW_ERROR is set.
       
  1478  *
       
  1479  * @see ucnv_fromAlgorithmic
       
  1480  * @see ucnv_convert
       
  1481  * @see ucnv_convertEx
       
  1482  * @see ucnv_fromUnicode
       
  1483  * @see ucnv_toUnicode
       
  1484  * @see ucnv_fromUChars
       
  1485  * @see ucnv_toUChars
       
  1486  * @stable ICU 2.6
       
  1487  */
       
  1488 U_STABLE int32_t U_EXPORT2
       
  1489 ucnv_fromAlgorithmic(UConverter *cnv,
       
  1490                      UConverterType algorithmicType,
       
  1491                      char *target, int32_t targetCapacity,
       
  1492                      const char *source, int32_t sourceLength,
       
  1493                      UErrorCode *pErrorCode);
       
  1494 
       
  1495 /**
       
  1496  * Frees up memory occupied by unused, cached converter shared data.
       
  1497  *
       
  1498  * @return the number of cached converters successfully deleted
       
  1499  * @see ucnv_close
       
  1500  * @stable ICU 2.0
       
  1501  */
       
  1502 U_STABLE int32_t U_EXPORT2
       
  1503 ucnv_flushCache(void);
       
  1504 
       
  1505 /**
       
  1506  * Returns the number of available converters, as per the alias file.
       
  1507  *
       
  1508  * @return the number of available converters
       
  1509  * @see ucnv_getAvailableName
       
  1510  * @stable ICU 2.0
       
  1511  */
       
  1512 U_STABLE int32_t U_EXPORT2
       
  1513 ucnv_countAvailable(void);
       
  1514 
       
  1515 /**
       
  1516  * Gets the canonical converter name of the specified converter from a list of
       
  1517  * all available converters contaied in the alias file. All converters
       
  1518  * in this list can be opened.
       
  1519  *
       
  1520  * @param n the index to a converter available on the system (in the range <TT>[0..ucnv_countAvaiable()]</TT>)
       
  1521  * @return a pointer a string (library owned), or <TT>NULL</TT> if the index is out of bounds.
       
  1522  * @see ucnv_countAvailable
       
  1523  * @stable ICU 2.0
       
  1524  */
       
  1525 U_STABLE const char* U_EXPORT2
       
  1526 ucnv_getAvailableName(int32_t n);
       
  1527 
       
  1528 /**
       
  1529  * Returns a UEnumeration to enumerate all of the canonical converter
       
  1530  * names, as per the alias file, regardless of the ability to open each
       
  1531  * converter.
       
  1532  *
       
  1533  * @return A UEnumeration object for getting all the recognized canonical
       
  1534  *   converter names.
       
  1535  * @see ucnv_getAvailableName
       
  1536  * @see uenum_close
       
  1537  * @see uenum_next
       
  1538  * @stable ICU 2.4
       
  1539  */
       
  1540 U_STABLE UEnumeration * U_EXPORT2
       
  1541 ucnv_openAllNames(UErrorCode *pErrorCode);
       
  1542 
       
  1543 /**
       
  1544  * Gives the number of aliases for a given converter or alias name.
       
  1545  * If the alias is ambiguous, then the preferred converter is used
       
  1546  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
       
  1547  * This method only enumerates the listed entries in the alias file.
       
  1548  * @param alias alias name
       
  1549  * @param pErrorCode error status
       
  1550  * @return number of names on alias list for given alias
       
  1551  * @stable ICU 2.0
       
  1552  */
       
  1553 U_STABLE uint16_t U_EXPORT2 
       
  1554 ucnv_countAliases(const char *alias, UErrorCode *pErrorCode);
       
  1555 
       
  1556 /**
       
  1557  * Gives the name of the alias at given index of alias list.
       
  1558  * This method only enumerates the listed entries in the alias file.
       
  1559  * If the alias is ambiguous, then the preferred converter is used
       
  1560  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
       
  1561  * @param alias alias name
       
  1562  * @param n index in alias list
       
  1563  * @param pErrorCode result of operation
       
  1564  * @return returns the name of the alias at given index
       
  1565  * @see ucnv_countAliases
       
  1566  * @stable ICU 2.0
       
  1567  */
       
  1568 U_STABLE const char * U_EXPORT2 
       
  1569 ucnv_getAlias(const char *alias, uint16_t n, UErrorCode *pErrorCode);
       
  1570 
       
  1571 /**
       
  1572  * Fill-up the list of alias names for the given alias.
       
  1573  * This method only enumerates the listed entries in the alias file.
       
  1574  * If the alias is ambiguous, then the preferred converter is used
       
  1575  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
       
  1576  * @param alias alias name
       
  1577  * @param aliases fill-in list, aliases is a pointer to an array of
       
  1578  *        <code>ucnv_countAliases()</code> string-pointers
       
  1579  *        (<code>const char *</code>) that will be filled in.
       
  1580  *        The strings themselves are owned by the library.
       
  1581  * @param pErrorCode result of operation
       
  1582  * @stable ICU 2.0
       
  1583  */
       
  1584 U_STABLE void U_EXPORT2 
       
  1585 ucnv_getAliases(const char *alias, const char **aliases, UErrorCode *pErrorCode);
       
  1586 
       
  1587 /**
       
  1588  * Return a new UEnumeration object for enumerating all the
       
  1589  * alias names for a given converter that are recognized by a standard.
       
  1590  * This method only enumerates the listed entries in the alias file.
       
  1591  * The convrtrs.txt file can be modified to change the results of
       
  1592  * this function.
       
  1593  * The first result in this list is the same result given by
       
  1594  * <code>ucnv_getStandardName</code>, which is the default alias for
       
  1595  * the specified standard name. The returned object must be closed with
       
  1596  * <code>uenum_close</code> when you are done with the object.
       
  1597  *
       
  1598  * @param convName original converter name
       
  1599  * @param standard name of the standard governing the names; MIME and IANA
       
  1600  *      are such standards
       
  1601  * @param pErrorCode The error code
       
  1602  * @return A UEnumeration object for getting all aliases that are recognized
       
  1603  *      by a standard. If any of the parameters are invalid, NULL
       
  1604  *      is returned.
       
  1605  * @see ucnv_getStandardName
       
  1606  * @see uenum_close
       
  1607  * @see uenum_next
       
  1608  * @stable ICU 2.2
       
  1609  */
       
  1610 U_STABLE UEnumeration * U_EXPORT2
       
  1611 ucnv_openStandardNames(const char *convName,
       
  1612                        const char *standard,
       
  1613                        UErrorCode *pErrorCode);
       
  1614 
       
  1615 /**
       
  1616  * Gives the number of standards associated to converter names.
       
  1617  * @return number of standards
       
  1618  * @stable ICU 2.0
       
  1619  */
       
  1620 U_STABLE uint16_t U_EXPORT2
       
  1621 ucnv_countStandards(void);
       
  1622 
       
  1623 /**
       
  1624  * Gives the name of the standard at given index of standard list.
       
  1625  * @param n index in standard list
       
  1626  * @param pErrorCode result of operation
       
  1627  * @return returns the name of the standard at given index. Owned by the library.
       
  1628  * @stable ICU 2.0
       
  1629  */
       
  1630 U_STABLE const char * U_EXPORT2
       
  1631 ucnv_getStandard(uint16_t n, UErrorCode *pErrorCode);
       
  1632 
       
  1633 /**
       
  1634  * Returns a standard name for a given converter name.
       
  1635  * <p>
       
  1636  * Example alias table:<br>
       
  1637  * conv alias1 { STANDARD1 } alias2 { STANDARD1* }
       
  1638  * <p>
       
  1639  * Result of ucnv_getStandardName("conv", "STANDARD1") from example
       
  1640  * alias table:<br>
       
  1641  * <b>"alias2"</b>
       
  1642  *
       
  1643  * @param name original converter name
       
  1644  * @param standard name of the standard governing the names; MIME and IANA
       
  1645  *        are such standards
       
  1646  * @param pErrorCode result of operation
       
  1647  * @return returns the standard converter name;
       
  1648  *         if a standard converter name cannot be determined,
       
  1649  *         then <code>NULL</code> is returned. Owned by the library.
       
  1650  * @stable ICU 2.0
       
  1651  */
       
  1652 U_STABLE const char * U_EXPORT2
       
  1653 ucnv_getStandardName(const char *name, const char *standard, UErrorCode *pErrorCode);
       
  1654 
       
  1655 /**
       
  1656  * This function will return the internal canonical converter name of the
       
  1657  * tagged alias. This is the opposite of ucnv_openStandardNames, which
       
  1658  * returns the tagged alias given the canonical name.
       
  1659  * <p>
       
  1660  * Example alias table:<br>
       
  1661  * conv alias1 { STANDARD1 } alias2 { STANDARD1* }
       
  1662  * <p>
       
  1663  * Result of ucnv_getStandardName("alias1", "STANDARD1") from example
       
  1664  * alias table:<br>
       
  1665  * <b>"conv"</b>
       
  1666  *
       
  1667  * @return returns the canonical converter name;
       
  1668  *         if a standard or alias name cannot be determined,
       
  1669  *         then <code>NULL</code> is returned. The returned string is
       
  1670  *         owned by the library.
       
  1671  * @see ucnv_getStandardName
       
  1672  * @stable ICU 2.4
       
  1673  */
       
  1674 U_STABLE const char * U_EXPORT2
       
  1675 ucnv_getCanonicalName(const char *alias, const char *standard, UErrorCode *pErrorCode);
       
  1676 
       
  1677 /**
       
  1678  * returns the current default converter name.
       
  1679  *
       
  1680  * @return returns the current default converter name;
       
  1681  *         if a default converter name cannot be determined,
       
  1682  *         then <code>NULL</code> is returned.
       
  1683  *         Storage owned by the library
       
  1684  * @see ucnv_setDefaultName
       
  1685  * @stable ICU 2.0
       
  1686  */
       
  1687 U_STABLE const char * U_EXPORT2
       
  1688 ucnv_getDefaultName(void);
       
  1689 
       
  1690 /**
       
  1691  * sets the current default converter name. Caller must own the storage for 'name'
       
  1692  * and preserve it indefinitely. 
       
  1693  * @param name the converter name to be the default (must exist).
       
  1694  * @see ucnv_getDefaultName
       
  1695  * @system SYSTEM API
       
  1696  * @stable ICU 2.0
       
  1697  */
       
  1698 U_STABLE void U_EXPORT2
       
  1699 ucnv_setDefaultName(const char *name);
       
  1700 
       
  1701 /**
       
  1702  * Fixes the backslash character mismapping.  For example, in SJIS, the backslash 
       
  1703  * character in the ASCII portion is also used to represent the yen currency sign.  
       
  1704  * When mapping from Unicode character 0x005C, it's unclear whether to map the 
       
  1705  * character back to yen or backslash in SJIS.  This function will take the input
       
  1706  * buffer and replace all the yen sign characters with backslash.  This is necessary
       
  1707  * when the user tries to open a file with the input buffer on Windows.
       
  1708  * This function will test the converter to see whether such mapping is
       
  1709  * required.  You can sometimes avoid using this function by using the correct version
       
  1710  * of Shift-JIS.
       
  1711  *
       
  1712  * @param cnv The converter representing the target codepage.
       
  1713  * @param source the input buffer to be fixed
       
  1714  * @param sourceLen the length of the input buffer
       
  1715  * @see ucnv_isAmbiguous
       
  1716  * @stable ICU 2.0
       
  1717  */
       
  1718 U_STABLE void U_EXPORT2
       
  1719 ucnv_fixFileSeparator(const UConverter *cnv, UChar *source, int32_t sourceLen);
       
  1720 
       
  1721 /**
       
  1722  * Determines if the converter contains ambiguous mappings of the same
       
  1723  * character or not.
       
  1724  * @param cnv the converter to be tested
       
  1725  * @return TRUE if the converter contains ambiguous mapping of the same 
       
  1726  * character, FALSE otherwise.
       
  1727  * @stable ICU 2.0
       
  1728  */
       
  1729 U_STABLE UBool U_EXPORT2
       
  1730 ucnv_isAmbiguous(const UConverter *cnv);
       
  1731 
       
  1732 /**
       
  1733  * Sets the converter to use fallback mapping or not.
       
  1734  * @param cnv The converter to set the fallback mapping usage on.
       
  1735  * @param usesFallback TRUE if the user wants the converter to take advantage of the fallback 
       
  1736  * mapping, FALSE otherwise.
       
  1737  * @stable ICU 2.0
       
  1738  */
       
  1739 U_STABLE void U_EXPORT2 
       
  1740 ucnv_setFallback(UConverter *cnv, UBool usesFallback);
       
  1741 
       
  1742 /**
       
  1743  * Determines if the converter uses fallback mappings or not.
       
  1744  * @param cnv The converter to be tested
       
  1745  * @return TRUE if the converter uses fallback, FALSE otherwise.
       
  1746  * @stable ICU 2.0
       
  1747  */
       
  1748 U_STABLE UBool U_EXPORT2 
       
  1749 ucnv_usesFallback(const UConverter *cnv);
       
  1750 
       
  1751 /**
       
  1752  * Detects Unicode signature byte sequences at the start of the byte stream
       
  1753  * and returns the charset name of the indicated Unicode charset.
       
  1754  * NULL is returned when no Unicode signature is recognized.
       
  1755  * The number of bytes in the signature is output as well.
       
  1756  *
       
  1757  * The caller can ucnv_open() a converter using the charset name.
       
  1758  * The first code unit (UChar) from the start of the stream will be U+FEFF
       
  1759  * (the Unicode BOM/signature character) and can usually be ignored.
       
  1760  *
       
  1761  * For most Unicode charsets it is also possible to ignore the indicated
       
  1762  * number of initial stream bytes and start converting after them.
       
  1763  * However, there are stateful Unicode charsets (UTF-7 and BOCU-1) for which
       
  1764  * this will not work. Therefore, it is best to ignore the first output UChar
       
  1765  * instead of the input signature bytes.
       
  1766  * <p>
       
  1767  * Usage:
       
  1768  * @code     
       
  1769  *      UErrorCode err = U_ZERO_ERROR;
       
  1770  *      char input[] = { '\xEF','\xBB', '\xBF','\x41','\x42','\x43' };
       
  1771  *      int32_t signatureLength = 0;
       
  1772  *      char *encoding = ucnv_detectUnicodeSignatures(input,sizeof(input),&signatureLength,&err);
       
  1773  *      UConverter *conv = NULL;
       
  1774  *      UChar output[100];
       
  1775  *      UChar *target = output, *out;
       
  1776  *      char *source = input;
       
  1777  *      if(encoding!=NULL && U_SUCCESS(err)){
       
  1778  *          // should signature be discarded ?
       
  1779  *          conv = ucnv_open(encoding, &err);
       
  1780  *          // do the conversion
       
  1781  *          ucnv_toUnicode(conv,
       
  1782  *                         target, output + sizeof(output)/U_SIZEOF_UCHAR,
       
  1783  *                         source, input + sizeof(input),
       
  1784  *                         NULL, TRUE, &err);
       
  1785  *          out = output;
       
  1786  *          if (discardSignature){
       
  1787  *              ++out; // ignore initial U+FEFF
       
  1788  *          }
       
  1789  *          while(out != target) {
       
  1790  *              printf("%04x ", *out++);
       
  1791  *          }
       
  1792  *          puts("");
       
  1793  *      }
       
  1794  *     
       
  1795  * @endcode
       
  1796  *
       
  1797  * @param source            The source string in which the signature should be detected.
       
  1798  * @param sourceLength      Length of the input string, or -1 if terminated with a NUL byte.
       
  1799  * @param signatureLength   A pointer to int32_t to receive the number of bytes that make up the signature 
       
  1800  *                          of the detected UTF. 0 if not detected.
       
  1801  *                          Can be a NULL pointer.
       
  1802  * @param pErrorCode        A pointer to receive information about any errors that may occur during detection.
       
  1803  *                          Must be a valid pointer to an error code value, which must not indicate a failure
       
  1804  *                          before the function call.
       
  1805  * @return The name of the encoding detected. NULL if encoding is not detected. 
       
  1806  * @stable ICU 2.4
       
  1807  */
       
  1808 U_STABLE const char* U_EXPORT2
       
  1809 ucnv_detectUnicodeSignature(const char* source,
       
  1810                             int32_t sourceLength,
       
  1811                             int32_t *signatureLength,
       
  1812                             UErrorCode *pErrorCode);
       
  1813 
       
  1814 #endif
       
  1815 
       
  1816 #endif
       
  1817 /*_UCNV*/