The m17n Library

One of these values is set in MConverter->result.

Enumerator:

MCONVERSION_RESULT_SUCCESS	Code conversion is successful.
MCONVERSION_RESULT_INVALID_BYTE	On decoding, the source contains an invalid byte.
MCONVERSION_RESULT_INVALID_CHAR	On encoding, the source contains a character that cannot be encoded by the specified coding system.
MCONVERSION_RESULT_INSUFFICIENT_SRC	On decoding, the source ends with an incomplete byte sequence.
MCONVERSION_RESULT_INSUFFICIENT_DST	On encoding, the destination is too short to store the result.
MCONVERSION_RESULT_IO_ERROR	An I/O error occurred in the conversion.

enum MCodingType

Enumerator:

MCODING_TYPE_CHARSET	A coding system of this type supports charsets directly. The dimension of each charset defines the length of bytes to represent a single character of the charset, and a byte sequence directly represents the code-point of a character. The m17n library provides the default decoding and encoding routines of this type.
MCODING_TYPE_UTF	A coding system of this type supports byte sequences of a UTF (UTF-8, UTF-16, UTF-32) like structure. The m17n library provides the default decoding and encoding routines of this type.
MCODING_TYPE_ISO_2022	A coding system of this type supports byte sequences of an ISO-2022 like structure. The details of each structure are specified by `MCodingInfoISO2022` . The m17n library provides decoding and encoding routines of this type.
MCODING_TYPE_MISC	A coding system of this type is for byte sequences of miscellaneous structures. The m17n library does not provide decoding and encoding routines of this type. They must be provided by the application program.

enum MCodingFlagISO2022

Enumerator:

MCODING_ISO_RESET_AT_EOL	On encoding, reset the invocation and designation status to initial at end of line.
MCODING_ISO_RESET_AT_CNTL	On encoding, reset the invocation and designation status to initial before any control codes.
MCODING_ISO_EIGHT_BIT	Use the right graphic plane.
MCODING_ISO_LONG_FORM	Use the non-standard 4 bytes format for designation sequence for charsets JISX0208-1978, GB2312, and JISX0208-1983.
MCODING_ISO_DESIGNATION_G0	On encoding, unless explicitly specified, designate charsets to G0.
MCODING_ISO_DESIGNATION_G1	On encoding, unless explicitly specified, designate charsets except for ASCII to G1.
MCODING_ISO_DESIGNATION_CTEXT	On encoding, unless explicitly specified, designate 94-chars charsets to G0, 96-chars charsets to G1.
MCODING_ISO_DESIGNATION_CTEXT_EXT	On encoding, encode such charsets not conforming to ISO-2022 by ESC % / ..., and encode non-supported Unicode characters by ESC % G ... ESC % @ . On decoding, handle those escape sequences.
MCODING_ISO_LOCKING_SHIFT	Use locking shift.
MCODING_ISO_SINGLE_SHIFT	Use single shift (SS2 (0x8E or ESC N), SS3 (0x8F or ESC O)).
MCODING_ISO_SINGLE_SHIFT_7	Use 7-bit single shift 2 (SS2 (0x19)).
MCODING_ISO_EUC_TW_SHIFT	Use EUC-TW like special shifting.
MCODING_ISO_ISO6429	Use ISO-6429 escape sequences to indicate direction. Not yet implemented.
MCODING_ISO_REVISION_NUMBER	On encoding, if a charset has revision number, produce escape sequences to specify the number.
MCODING_ISO_FULL_SUPPORT	Support all ISO-2022 charsets.
MCODING_ISO_FLAG_MAX

MSymbol mconv_define_coding	(	const char *	name,
		MPlist *	plist,
		int()(MConverter )	resetter,
		int()(const unsigned char , int, MText , MConverter )	decoder,
		int()(MText , int, int, unsigned char , int, MConverter )	encoder,
		void *	extra_info
	)

The mconv_define_coding() function defines a new coding system and makes it accessible via a symbol whose name is name. plist specifies parameters of the coding system as below:

Key is Mtype, value is a symbol
The value specifies the type of the coding system. It must be Mcharset, Mutf, Miso_2022, or Mnil.
If the type is Mcharset, extra_info is ignored.
If the type is Mutf, extra_info must be a pointer to MCodingInfoUTF.
If the type is Miso_2022, extra_info must be a pointer to MCodingInfoISO2022.
If the type is Mnil, the argument resetter, decoder, and encoder must be supplied. extra_info is ignored. Otherwise, they can be NULL and the m17n library provides proper defaults.
Key is Mcharsets, value is a plist
The value specifies a list charsets supported by the coding system. The keys of the plist must be Msymbol, and the values must be symbols representing charsets.
Key is Mflags, value is a plist
If the type is Miso_2022, the values specifies flags to control the ISO 2022 interpreter. The keys of the plist must e Msymbol, and values must be one of the following.
- Mreset_at_eol
  If this flag exists, designation and invocation status is reset to the initial state at the end of line.
- Mreset_at_cntl
  If this flag exists, designation and invocation status is reset to the initial state at a control character.
- Meight_bit
  If this flag exists, the graphic plane right is used.
- Mlong_form
  If this flag exists, the over-long escape sequences (ESC '$' '(' <final_byte>) are used for designating the CCS JISX0208.1978, GB2312, and JISX0208.
- Mdesignation_g0
  If this flag and Mfull_support exists, designates charsets not listed in the charset list to the graphic register G0.
- Mdesignation_g1
  If this flag and Mfull_support exists, designates charsets not listed in the charset list to the graphic register G1.
- Mdesignation_ctext
  If this flag and Mfull_support exists, designates charsets not listed in the charset list to a graphic register G0 or G1 based on the criteria of the Compound Text.
- Mdesignation_ctext_ext
  If this flag and Mfull_support exists, designates charsets not listed in the charset list to a graphic register G0 or G1, or use extended segment for such charsets based on the criteria of the Compound Text.
- Mlocking_shift
  If this flag exists, use locking shift.
- Msingle_shift
  If this flag exists, use single shift.
- Msingle_shift_7
  If this flag exists, use 7-bit single shift code (0x19).
- Meuc_tw_shift
  If this flag exists, use a special shifting according to EUC-TW.
- Miso_6429
  This flag is currently ignored.
- Mrevision_number
  If this flag exists, use a revision number escape sequence to designate a charset that has a revision number.
- Mfull_support
  If this flag exists, support all charsets registered in the International Registry.
Key is Mdesignation, value is a plist
If the type is Miso_2022, the value specifies how to designate each supported characters. The keys of the plist must be Minteger, and the values must be numbers indicating a graphic registers. The Nth element value is for the Nth charset of the charset list. The value 0..3 means that it is assumed that a charset is already designated to the graphic register 0..3. The negative value G (-4..-1) means that a charset is not designated to any register at first, and if necessary, is designated to the (G+4) graphic register.
Key is Minvocation, value is a plist
If the type is Miso_2022, the value specifies how to invocate each graphic registers. The plist length must be one or two. The keys of the plist must be Minteger, and the values must be numbers indicating a graphic register. The value of the first element specifies which graphic register is invocated to the graphic plane left. If the length is one, no graphic register is invocated to the graphic plane right. Otherwise, the value of the second element specifies which graphic register is invocated to the graphic plane right.
Key is Mcode_unit, value is an integer
If the type is Mutf, the value specifies the bit length of a code-unit. It must be 8, 16, or 32.
Key is Mbom, value is a symbol
If the type is Mutf and the code-unit bit length is 16 or 32, it specifies whether or not to use BOM (Byte Order Mark). If the value is Mnil (default), BOM is not used, else if the value is Mmaybe, the existence of BOM is detected at decoding time, else BOM is used.
Key is Mlittle_endian, value is a symbol
If the type is Mutf and the code-unit bit length is 16 or 32, it specifies whether or not the encoding is little endian. If the value is Mnil (default), it is big endian, else it is little endian.

resetter is a pointer to a function that resets a converter for the coding system to the initial status. The pointed function is called with one argument, a pointer to a converter object.

decoder is a pointer to a function that decodes a byte sequence according to the coding system. The pointed function is called with four arguments:

A pointer to the byte sequence to decode.
The number of bytes to decode.
A pointer to an M-text to which the decoded characters are appended.
A pointer to a converter object.

decoder must return 0 if it succeeds. Otherwise it must return -1.

encoder is a pointer to a function that encodes an M-text according to the coding system. The pointed function is called with six arguments:

A pointer to the M-text to encode.
The starting position of the encoding.
The ending position of the encoding.
A pointer to a memory area where the produced bytes are stored.
The size of the memory area.
A pointer to a converter object.

encoder must return 0 if it succeeds. Otherwise it must return -1.

extra_info is a pointer to a data structure that contains extra information about the coding system. The type of the data structure depends on type.

Return value:

If the operation was successful, mconv_define_coding() returns a symbol whose name is name. If an error is detected, it returns Mnil and assigns an error code to the external variable merror_code.

Errors:: MERROR_CODING

MSymbol mconv_resolve_coding ( MSymbol symbol )

The mconv_resolve_coding() function returns symbol if it represents a coding system. Otherwise, canonicalize symbol as to a coding system name, and if the canonicalized name represents a coding system, return it. Otherwise, return Mnil.

int mconv_list_codings ( MSymbol ** symbols )

The mconv_list_codings() function makes an array of symbols representing a coding system, stores the pointer to the array in a place pointed to by symbols, and returns the length of the array.

MConverter* mconv_buffer_converter	(	MSymbol	name,
		const unsigned char *	buf,
		int	n
	)

The mconv_buffer_converter() function creates a pointer to a code converter for coding system name. The code converter is bound to buffer area of n bytes pointed to by buf. Subsequent decodings and encodings are done to/from this buffer area.

name can be Mnil. In this case, a coding system associated with the current locale (LC_CTYPE) is used.

Return value:: If the operation was successful, mconv_buffer_converter() returns the created code converter. Otherwise it returns NULL and assigns an error code to the external variable merror_code.

Errors:: MERROR_SYMBOL, MERROR_CODING

See Also:: mconv_stream_converter()

MConverter* mconv_stream_converter	(	MSymbol	name,
		FILE *	fp
	)

The mconv_stream_converter() function creates a pointer to a code converter for coding system name. The code converter is bound to stream fp. Subsequent decodings and encodings are done to/from this stream.

name can be Mnil. In this case, a coding system associated with the current locale (LC_CTYPE) is used.

Return value: If the operation was successful, mconv_stream_converter(): returns the created code converter. Otherwise it returns NULL and assigns an error code to the external variable merror_code.

Errors:: MERROR_SYMBOL, MERROR_CODING

See Also:: mconv_buffer_converter()

int mconv_reset_converter ( MConverter * converter )

The mconv_reset_converter() function resets code converter converter to the initial state.

Return value:: If converter->coding has its own reseter function, mconv_reset_converter() returns the result of that function applied to converter. Otherwise it returns 0.

void mconv_free_converter ( MConverter * converter )

The mconv_free_converter() function frees the code converter converter.

MConverter* mconv_rebind_buffer	(	MConverter *	converter,
		const unsigned char *	buf,
		int	n
	)

The mconv_rebind_buffer() function binds buffer area of n bytes pointed to by buf to code converter converter. Subsequent decodings and encodings are done to/from this newly bound buffer area.

Return value:: This function always returns converter.

See Also:: mconv_rebind_stream()

MConverter* mconv_rebind_stream	(	MConverter *	converter,
		FILE *	fp
	)

The mconv_rebind_stream() function binds stream fp to code converter converter. Following decodings and encodings are done to/from this newly bound stream.

Return value:: This function always returns converter.

See Also:: mconv_rebind_buffer()

MText* mconv_decode	(	MConverter *	converter,
		MText *	mt
	)

The mconv_decode() function decodes a byte sequence and appends the result at the end of M-text mt. The source byte sequence is taken from either the buffer area or the stream that is currently bound to converter.

Return value:: If the operation was successful, mconv_decode() returns updated mt. Otherwise it returns NULL and assigns an error code to the external variable merror_code.

Errors:: MERROR_IO, MERROR_CODING

See Also:: mconv_rebind_buffer(), mconv_rebind_stream(), mconv_encode(), mconv_encode_range(), mconv_decode_buffer(), mconv_decode_stream()

MText* mconv_decode_buffer	(	MSymbol	name,
		const unsigned char *	buf,
		int	n
	)

The mconv_decode_buffer() function decodes n bytes of the buffer area pointed to by buf based on the coding system name. A temporary code converter for decoding is automatically created and freed.

Return value:: If the operation was successful, mconv_decode_buffer() returns the resulting M-text. Otherwise it returns NULL and assigns an error code to the external variable merror_code.

Errors:: MERROR_IO, MERROR_CODING

See Also:: mconv_decode(), mconv_decode_stream()

MText* mconv_decode_stream	(	MSymbol	name,
		FILE *	fp
	)

The mconv_decode_stream() function decodes the entire byte sequence read in from stream fp based on the coding system name. A code converter for decoding is automatically created and freed.

Return value:: If the operation was successful, mconv_decode_stream() returns the resulting M-text. Otherwise it returns NULL and assigns an error code to the external variable merror_code.

Errors:: MERROR_IO, MERROR_CODING

See Also:: mconv_decode(), mconv_decode_buffer()

int mconv_encode	(	MConverter *	converter,
		MText *	mt
	)

The mconv_encode() function encodes M-text mt and writes the resulting byte sequence into the buffer area or the stream that is currently bound to code converter converter.

Return value:: If the operation was successful, mconv_encode() returns the number of written bytes. Otherwise it returns -1 and assigns an error code to the external variable merror_code.

Errors:: MERROR_IO, MERROR_CODING

See Also:: mconv_rebind_buffer(), mconv_rebind_stream(), mconv_decode(), mconv_encode_range()

int mconv_encode_range	(	MConverter *	converter,
		MText *	mt,
		int	from,
		int	to
	)

The mconv_encode_range() function encodes the text between from (inclusive) and to (exclusive) in M-text mt and writes the resulting byte sequence into the buffer area or the stream that is currently bound to code converter converter.

Return value:: If the operation was successful, mconv_encode_range() returns the number of written bytes. Otherwise it returns -1 and assigns an error code to the external variable merror_code.

Errors:: MERROR_RANGE, MERROR_IO, MERROR_CODING

See Also:: mconv_rebind_buffer(), mconv_rebind_stream(), mconv_decode(), mconv_encode()

int mconv_encode_buffer	(	MSymbol	name,
		MText *	mt,
		unsigned char *	buf,
		int	n
	)

The mconv_encode_buffer() function encodes M-text mt based on coding system name and writes the resulting byte sequence into the buffer area pointed to by buf. At most n bytes are written. A temporary code converter for encoding is automatically created and freed.

Return value:: If the operation was successful, mconv_encode_buffer() returns the number of written bytes. Otherwise it returns -1 and assigns an error code to the external variable merror_code.

Errors:: MERROR_IO, MERROR_CODING

See Also:: mconv_encode(), mconv_encode_stream()

int mconv_encode_stream	(	MSymbol	name,
		MText *	mt,
		FILE *	fp
	)

The mconv_encode_stream() function encodes M-text mt based on coding system name and writes the resulting byte sequence to stream fp. A temporary code converter for encoding is automatically created and freed.

Return value:: If the operation was successful, mconv_encode_stream() returns the number of written bytes. Otherwise it returns -1 and assigns an error code to the external variable merror_code.

Errors:: MERROR_IO, MERROR_CODING

See Also:: mconv_encode(), mconv_encode_buffer(), mconv_encode_file()

int mconv_getc ( MConverter * converter )

The mconv_getc() function reads one character from the buffer area or the stream that is currently bound to code converter converter. The decoder of converter is used to decode the byte sequence. The internal status of converter is updated appropriately.

Return value:: If the operation was successful, mconv_getc() returns the character read in. If the input source reaches EOF, it returns EOF without changing the external variable merror_code. If an error is detected, it returns EOF and assigns an error code to merror_code.

Errors:: MERROR_CODING

See Also:: mconv_ungetc(), mconv_putc(), mconv_gets()

int mconv_ungetc	(	MConverter *	converter,
		int	c
	)

The mconv_ungetc() function pushes character c back to code converter converter. Any number of characters can be pushed back. The lastly pushed back character is firstly read by the subsequent mconv_getc() call. The characters pushed back are registered only in converter; they are not written to the input source. The internal status of converter is updated appropriately.

Return value:: If the operation was successful, mconv_ungetc() returns c. Otherwise it returns EOF and assigns an error code to the external variable merror_code.

Errors:: MERROR_CODING, MERROR_CHAR

See Also:: mconv_getc(), mconv_putc(), mconv_gets()

int mconv_putc	(	MConverter *	converter,
		int	c
	)

The mconv_putc() function writes character c to the buffer area or the stream that is currently bound to code converter converter. The encoder of converter is used to encode the character. The number of bytes actually written is set to the nbytes member of converter. The internal status of converter is updated appropriately.

Return value:: If the operation was successful, mconv_putc() returns c. If an error is detected, it returns EOF and assigns an error code to the external variable merror_code.

Errors:: MERROR_CODING, MERROR_IO, MERROR_CHAR

See Also:: mconv_getc(), mconv_ungetc(), mconv_gets()

MText* mconv_gets	(	MConverter *	converter,
		MText *	mt
	)

The mconv_gets() function reads one line from the buffer area or the stream that is currently bound to code converter converter. The decoder of converter is used for decoding. The decoded character sequence is appended at the end of M-text mt. The final newline character in the original byte sequence is not appended. The internal status of converter is updated appropriately.

Return value:: If the operation was successful, mconv_gets() returns the modified mt. If it encounters EOF without reading a single character, it returns mt without changing it. If an error is detected, it returns NULL and assigns an error code to merror_code.

Errors:: MERROR_CODING

See Also:: mconv_getc(), mconv_ungetc(), mconv_putc()

MSymbol Mcoding_us_ascii

The symbol Mcoding_us_ascii has name "us-ascii" and represents a coding system for the CES US-ASCII.

MSymbol Mcoding_iso_8859_1

The symbol Mcoding_iso_8859_1 has name "iso-8859-1" and represents a coding system for the CES ISO-8859-1.

MSymbol Mcoding_utf_8

The symbol Mcoding_utf_8 has name "utf-8" and represents a coding system for the CES UTF-8.

MSymbol Mcoding_utf_8_full

The symbol Mcoding_utf_8_full has name "utf-8-full" and represents a coding system that is a extension of UTF-8. This coding system uses the same encoding algorithm as UTF-8 but is not limited to the Unicode characters. It can encode all characters supported by the m17n library.

MSymbol Mcoding_utf_16

The symbol Mcoding_utf_16 has name "utf-16" and represents a coding system for the CES UTF-16 (RFC 2279).

MSymbol Mcoding_utf_16be

The symbol Mcoding_utf_16be has name "utf-16be" and represents a coding system for the CES UTF-16BE (RFC 2279).

MSymbol Mcoding_utf_16le

The symbol Mcoding_utf_16le has name "utf-16le" and represents a coding system for the CES UTF-16LE (RFC 2279).

MSymbol Mcoding_utf_32

The symbol Mcoding_utf_32 has name "utf-32" and represents a coding system for the CES UTF-32 (RFC 2279).

MSymbol Mcoding_utf_32be

The symbol Mcoding_utf_32be has name "utf-32be" and represents a coding system for the CES UTF-32BE (RFC 2279).

MSymbol Mcoding_utf_32le

The symbol Mcoding_utf_32le has name "utf-32le" and represents a coding system for the CES UTF-32LE (RFC 2279).

MSymbol Mcoding_sjis

The symbol Mcoding_sjis has name "sjis" and represents a coding system for the CES Shift-JIS.

MSymbol Mtype

Parameter key for mconv_define_coding() (which see).

MSymbol Mcharsets

Parameter key for mconv_define_coding() (which see).

MSymbol Mflags

Parameter key for mconv_define_coding() (which see).

MSymbol Mdesignation

Parameter key for mconv_define_coding() (which see).

MSymbol Minvocation

Parameter key for mconv_define_coding() (which see).

MSymbol Mcode_unit

Parameter key for mconv_define_coding() (which see).

MSymbol Mbom

Parameter key for mconv_define_coding() (which see).

MSymbol Mlittle_endian

Parameter key for mconv_define_coding() (which see).

MSymbol Mutf

Symbol that can be a value of the Mtype parameter of a coding system used in an argument to the mconv_define_coding() function (which see).

MSymbol Miso_2022

Symbol that can be a value of the Mtype parameter of a coding system used in an argument to the mconv_define_coding() function (which see).

MSymbol Mreset_at_eol