66.6.2 Coding System Properties

mnemonic

String to be displayed in the modeline when this coding system is active.

eol-type

End-of-line conversion to be used. It should be one of the types listed in EOL Conversion.

eol-lf

The coding system which is the same as this one, except that it uses the Unix line-breaking convention.

eol-crlf

The coding system which is the same as this one, except that it uses the DOS line-breaking convention.

eol-cr

The coding system which is the same as this one, except that it uses the Macintosh line-breaking convention.

post-read-conversion

Function called after a file has been read in, to perform the decoding. Called with two arguments, start and end, denoting a region of the current buffer to be decoded.

pre-write-conversion

Function called before a file is written out, to perform the encoding. Called with two arguments, start and end, denoting a region of the current buffer to be encoded.

The following additional properties are recognized if type is iso2022:

charset-g0

charset-g1

charset-g2

charset-g3

The character set initially designated to the G0 - G3 registers. The value should be one of

• A charset object (designate that character set)
• nil (do not ever use this register)
• t (no character set is initially designated to the register, but may be later on; this automatically sets the corresponding force-g*-on-output property)

force-g0-on-output

force-g1-on-output

force-g2-on-output

force-g3-on-output

If non-nil, send an explicit designation sequence on output before using the specified register.

short

If non-nil, use the short forms ‘ESC $ @’, ‘ESC $ A’, and ‘ESC $ B’ on output in place of the full designation sequences ‘ESC $ ( @’, ‘ESC $ ( A’, and ‘ESC $ ( B’.

no-ascii-eol

If non-nil, don’t designate ASCII to G0 at each end of line on output. Setting this to non-nil also suppresses other state-resetting that normally happens at the end of a line.

no-ascii-cntl

If non-nil, don’t designate ASCII to G0 before control chars on output.

seven

If non-nil, use 7-bit environment on output. Otherwise, use 8-bit environment.

lock-shift

If non-nil, use locking-shift (SO/SI) instead of single-shift or designation by escape sequence.

no-iso6429

If non-nil, don’t use ISO6429’s direction specification.

escape-quoted

If non-nil, literal control characters that are the same as the beginning of a recognized ISO 2022 or ISO 6429 escape sequence (in particular, ESC (0x1B), SO (0x0E), SI (0x0F), SS2 (0x8E), SS3 (0x8F), and CSI (0x9B)) are “quoted” with an escape character so that they can be properly distinguished from an escape sequence. (Note that doing this results in a non-portable encoding.) This encoding flag is used for byte-compiled files. Note that ESC is a good choice for a quoting character because there are no escape sequences whose second byte is a character from the Control-0 or Control-1 character sets; this is explicitly disallowed by the ISO 2022 standard.

input-charset-conversion

A list of conversion specifications, specifying conversion of characters in one charset to another when decoding is performed. Each specification is a list of two elements: the source charset, and the destination charset.

output-charset-conversion

A list of conversion specifications, specifying conversion of characters in one charset to another when encoding is performed. The form of each specification is the same as for input-charset-conversion.

The following additional properties are recognized (and required) if type is ccl:

decode

CCL program used for decoding (converting to internal format).

encode

CCL program used for encoding (converting to external format).

The following properties are used internally: eol-cr, eol-crlf, eol-lf, and base.