punycode.h

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00001 /* punycode.h --- Declarations for punycode functions.
00002  * Copyright (C) 2002, 2003, 2004  Simon Josefsson
00003  *
00004  * This file is part of GNU Libidn.
00005  *
00006  * GNU Libidn is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU Lesser General Public
00008  * License as published by the Free Software Foundation; either
00009  * version 2.1 of the License, or (at your option) any later version.
00010  *
00011  * GNU Libidn is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public
00017  * License along with GNU Libidn; if not, write to the Free Software
00018  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
00019  *
00020  */
00021 
00022 /*
00023  * This file is derived from RFC 3492bis written by Adam M. Costello.
00024  *
00025  * Disclaimer and license: Regarding this entire document or any
00026  * portion of it (including the pseudocode and C code), the author
00027  * makes no guarantees and is not responsible for any damage resulting
00028  * from its use.  The author grants irrevocable permission to anyone
00029  * to use, modify, and distribute it in any way that does not diminish
00030  * the rights of anyone else to use, modify, and distribute it,
00031  * provided that redistributed derivative works do not contain
00032  * misleading author or version information.  Derivative works need
00033  * not be licensed under similar terms.
00034  *
00035  * Copyright (C) The Internet Society (2003).  All Rights Reserved.
00036  *
00037  * This document and translations of it may be copied and furnished to
00038  * others, and derivative works that comment on or otherwise explain it
00039  * or assist in its implementation may be prepared, copied, published
00040  * and distributed, in whole or in part, without restriction of any
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00050  *
00051  * The limited permissions granted above are perpetual and will not be
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00056  * TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
00057  * BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
00058  * HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
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00060  */
00061 
00062 #ifndef _PUNYCODE_H
00063 #define _PUNYCODE_H
00064 
00065 #ifdef __cplusplus
00066 extern "C"
00067 {
00068 #endif
00069 
00070 #include <stddef.h>             /* size_t */
00071 #include <idn-int.h>            /* uint32_t */
00072 
00073   enum punycode_status
00074   {
00075     punycode_success = 0,
00076     punycode_bad_input = 1,     /* Input is invalid.                       */
00077     punycode_big_output = 2,    /* Output would exceed the space provided. */
00078     punycode_overflow = 3       /* Wider integers needed to process input. */
00079   };
00080 
00081   typedef enum
00082   {
00083     PUNYCODE_SUCCESS = punycode_success,
00084     PUNYCODE_BAD_INPUT = punycode_bad_input,
00085     PUNYCODE_BIG_OUTPUT = punycode_big_output,
00086     PUNYCODE_OVERFLOW = punycode_overflow
00087   } Punycode_status;
00088 
00089   extern const char *punycode_strerror (Punycode_status rc);
00090 
00091 /* punycode_uint needs to be unsigned and needs to be */
00092 /* at least 26 bits wide.                             */
00093 
00094   typedef uint32_t punycode_uint;
00095 
00096   extern int punycode_encode (size_t input_length,
00097                               const punycode_uint input[],
00098                               const unsigned char case_flags[],
00099                               size_t * output_length, char output[]);
00100 
00101 /*
00102     punycode_encode() converts a sequence of code points (presumed to be
00103     Unicode code points) to Punycode.
00104 
00105     Input arguments (to be supplied by the caller):
00106 
00107         input_length
00108             The number of code points in the input array and the number
00109             of flags in the case_flags array.
00110 
00111         input
00112             An array of code points.  They are presumed to be Unicode
00113             code points, but that is not strictly REQUIRED.  The
00114             array contains code points, not code units.  UTF-16 uses
00115             code units D800 through DFFF to refer to code points
00116             10000..10FFFF.  The code points D800..DFFF do not occur in
00117             any valid Unicode string.  The code points that can occur in
00118             Unicode strings (0..D7FF and E000..10FFFF) are also called
00119             Unicode scalar values.
00120 
00121         case_flags
00122             A null pointer or an array of boolean values parallel to
00123             the input array.  Nonzero (true, flagged) suggests that the
00124             corresponding Unicode character be forced to uppercase after
00125             being decoded (if possible), and zero (false, unflagged)
00126             suggests that it be forced to lowercase (if possible).
00127             ASCII code points (0..7F) are encoded literally, except that
00128             ASCII letters are forced to uppercase or lowercase according
00129             to the corresponding case flags.  If case_flags is a null
00130             pointer then ASCII letters are left as they are, and other
00131             code points are treated as unflagged.
00132 
00133     Output arguments (to be filled in by the function):
00134 
00135         output
00136             An array of ASCII code points.  It is *not* null-terminated;
00137             it will contain zeros if and only if the input contains
00138             zeros.  (Of course the caller can leave room for a
00139             terminator and add one if needed.)
00140 
00141     Input/output arguments (to be supplied by the caller and overwritten
00142     by the function):
00143 
00144         output_length
00145             The caller passes in the maximum number of ASCII code points
00146             that it can receive.  On successful return it will contain
00147             the number of ASCII code points actually output.
00148 
00149     Return value:
00150 
00151         Can be any of the punycode_status values defined above except
00152         punycode_bad_input.  If not punycode_success, then output_size
00153         and output might contain garbage.
00154 */
00155 
00156   extern int punycode_decode (size_t input_length,
00157                               const char input[],
00158                               size_t * output_length,
00159                               punycode_uint output[],
00160                               unsigned char case_flags[]);
00161 
00162 /*
00163     punycode_decode() converts Punycode to a sequence of code points
00164     (presumed to be Unicode code points).
00165 
00166     Input arguments (to be supplied by the caller):
00167 
00168         input_length
00169             The number of ASCII code points in the input array.
00170 
00171         input
00172             An array of ASCII code points (0..7F).
00173 
00174     Output arguments (to be filled in by the function):
00175 
00176         output
00177             An array of code points like the input argument of
00178             punycode_encode() (see above).
00179 
00180         case_flags
00181             A null pointer (if the flags are not needed by the caller)
00182             or an array of boolean values parallel to the output array.
00183             Nonzero (true, flagged) suggests that the corresponding
00184             Unicode character be forced to uppercase by the caller (if
00185             possible), and zero (false, unflagged) suggests that it
00186             be forced to lowercase (if possible).  ASCII code points
00187             (0..7F) are output already in the proper case, but their
00188             flags will be set appropriately so that applying the flags
00189             would be harmless.
00190 
00191     Input/output arguments (to be supplied by the caller and overwritten
00192     by the function):
00193 
00194         output_length
00195             The caller passes in the maximum number of code points
00196             that it can receive into the output array (which is also
00197             the maximum number of flags that it can receive into the
00198             case_flags array, if case_flags is not a null pointer).  On
00199             successful return it will contain the number of code points
00200             actually output (which is also the number of flags actually
00201             output, if case_flags is not a null pointer).  The decoder
00202             will never need to output more code points than the number
00203             of ASCII code points in the input, because of the way the
00204             encoding is defined.  The number of code points output
00205             cannot exceed the maximum possible value of a punycode_uint,
00206             even if the supplied output_length is greater than that.
00207 
00208     Return value:
00209 
00210         Can be any of the punycode_status values defined above.  If not
00211         punycode_success, then output_length, output, and case_flags
00212         might contain garbage.
00213 */
00214 
00215 #ifdef __cplusplus
00216 }
00217 #endif
00218 #endif                          /* _PUNYCODE_H */

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