168 lines
6.4 KiB
C
168 lines
6.4 KiB
C
/*
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punycode-sample.c 2.0.0 (2004-Mar-21-Sun)
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http://www.nicemice.net/idn/
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Adam M. Costello
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http://www.nicemice.net/amc/
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This is ANSI C code (C89) implementing Punycode 1.0.x.
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This single file contains three sections (an interface, an
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implementation, and a wrapper for testing) that would normally belong
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in three separate files (punycode.h, punycode.c, punycode-test.c), but
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here they are bundled into one file (punycode-sample.c) for convenient
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testing. Anyone wishing to reuse this code will probably want to split
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it apart.
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*/
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/************************************************************/
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/* Public interface (would normally go in its own .h file): */
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#include <limits.h>
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#include <stddef.h>
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enum punycode_status {
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punycode_success = 0,
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punycode_bad_input = 1, /* Input is invalid. */
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punycode_big_output = 2, /* Output would exceed the space provided. */
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punycode_overflow = 3 /* Wider integers needed to process input. */
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};
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/* punycode_uint needs to be unsigned and needs to be */
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/* at least 26 bits wide. The particular type can be */
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/* specified by defining PUNYCODE_UINT, otherwise a */
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/* suitable type will be chosen automatically. */
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#ifdef PUNYCODE_UINT
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typedef PUNYCODE_UINT punycode_uint;
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#elif UINT_MAX >= (1 << 26) - 1
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typedef unsigned int punycode_uint;
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#else
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typedef unsigned long punycode_uint;
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#endif
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enum punycode_status punycode_encode(
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size_t, /* input_length */
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const punycode_uint [], /* input */
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const unsigned char [], /* case_flags */
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size_t *, /* output_length */
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char [] /* output */
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);
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/*
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punycode_encode() converts a sequence of code points (presumed to be
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Unicode code points) to Punycode.
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Input arguments (to be supplied by the caller):
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input_length
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The number of code points in the input array and the number
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of flags in the case_flags array.
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input
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An array of code points. They are presumed to be Unicode
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code points, but that is not strictly necessary. The
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array contains code points, not code units. UTF-16 uses
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code units D800 through DFFF to refer to code points
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10000..10FFFF. The code points D800..DFFF do not occur in
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any valid Unicode string. The code points that can occur in
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Unicode strings (0..D7FF and E000..10FFFF) are also called
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Unicode scalar values.
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case_flags
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A null pointer or an array of boolean values parallel to
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the input array. Nonzero (true, flagged) suggests that the
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corresponding Unicode character be forced to uppercase after
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being decoded (if possible), and zero (false, unflagged)
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suggests that it be forced to lowercase (if possible).
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ASCII code points (0..7F) are encoded literally, except that
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ASCII letters are forced to uppercase or lowercase according
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to the corresponding case flags. If case_flags is a null
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pointer then ASCII letters are left as they are, and other
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code points are treated as unflagged.
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Output arguments (to be filled in by the function):
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output
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An array of ASCII code points. It is *not* null-terminated;
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it will contain zeros if and only if the input contains
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zeros. (Of course the caller can leave room for a
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terminator and add one if needed.)
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Input/output arguments (to be supplied by the caller and overwritten
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by the function):
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output_length
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The caller passes in the maximum number of ASCII code points
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that it can receive. On successful return it will contain
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the number of ASCII code points actually output.
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Return value:
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Can be any of the punycode_status values defined above except
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punycode_bad_input. If not punycode_success, then output_size
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and output might contain garbage.
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*/
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enum punycode_status punycode_decode(
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size_t, /* input_length */
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const char [], /* input */
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size_t *, /* output_length */
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punycode_uint [], /* output */
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unsigned char [] /* case_flags */
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);
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/*
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punycode_decode() converts Punycode to a sequence of code points
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(presumed to be Unicode code points).
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Input arguments (to be supplied by the caller):
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input_length
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The number of ASCII code points in the input array.
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input
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An array of ASCII code points (0..7F).
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Output arguments (to be filled in by the function):
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output
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An array of code points like the input argument of
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punycode_encode() (see above).
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case_flags
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A null pointer (if the flags are not needed by the caller)
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or an array of boolean values parallel to the output array.
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Nonzero (true, flagged) suggests that the corresponding
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Unicode character be forced to uppercase by the caller (if
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possible), and zero (false, unflagged) suggests that it
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be forced to lowercase (if possible). ASCII code points
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(0..7F) are output already in the proper case, but their
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flags will be set appropriately so that applying the flags
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would be harmless.
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Input/output arguments (to be supplied by the caller and overwritten
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by the function):
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output_length
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The caller passes in the maximum number of code points
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that it can receive into the output array (which is also
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the maximum number of flags that it can receive into the
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case_flags array, if case_flags is not a null pointer). On
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successful return it will contain the number of code points
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actually output (which is also the number of flags actually
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output, if case_flags is not a null pointer). The decoder
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will never need to output more code points than the number
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of ASCII code points in the input, because of the way the
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encoding is defined. The number of code points output
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cannot exceed the maximum possible value of a punycode_uint,
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even if the supplied output_length is greater than that.
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Return value:
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Can be any of the punycode_status values defined above. If not
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punycode_success, then output_length, output, and case_flags
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might contain garbage.
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*/
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