xref: /titanic_50/usr/src/lib/libc/port/locale/unicode.h (revision 3fc10f8cbc2fd5dd5cd13044edf9cb68a1ef422b)
1*3fc10f8cSRobert Mustacchi /*
2*3fc10f8cSRobert Mustacchi  * This file and its contents are supplied under the terms of the
3*3fc10f8cSRobert Mustacchi  * Common Development and Distribution License ("CDDL"), version 1.0.
4*3fc10f8cSRobert Mustacchi  * You may only use this file in accordance with the terms of version
5*3fc10f8cSRobert Mustacchi  * 1.0 of the CDDL.
6*3fc10f8cSRobert Mustacchi  *
7*3fc10f8cSRobert Mustacchi  * A full copy of the text of the CDDL should have accompanied this
8*3fc10f8cSRobert Mustacchi  * source.  A copy of the CDDL is also available via the Internet at
9*3fc10f8cSRobert Mustacchi  * http://www.illumos.org/license/CDDL.
10*3fc10f8cSRobert Mustacchi  */
11*3fc10f8cSRobert Mustacchi 
12*3fc10f8cSRobert Mustacchi /*
13*3fc10f8cSRobert Mustacchi  * Copyright 2020 Robert Mustacchi
14*3fc10f8cSRobert Mustacchi  */
15*3fc10f8cSRobert Mustacchi 
16*3fc10f8cSRobert Mustacchi #ifndef _UNICODE_H
17*3fc10f8cSRobert Mustacchi #define	_UNICODE_H
18*3fc10f8cSRobert Mustacchi 
19*3fc10f8cSRobert Mustacchi /*
20*3fc10f8cSRobert Mustacchi  * Common definitions for dealing with Unicode.
21*3fc10f8cSRobert Mustacchi  *
22*3fc10f8cSRobert Mustacchi  * UTF-16 encodes data as a series of two byte values. However, there are more
23*3fc10f8cSRobert Mustacchi  * than 16-bit of code points. Code points inside of the first 16-bits are
24*3fc10f8cSRobert Mustacchi  * referred to as existing in the 'basic multilingual plane' (BMP). Those
25*3fc10f8cSRobert Mustacchi  * outside of it are in the 'supplementary plane'. When such a code point is
26*3fc10f8cSRobert Mustacchi  * encountered, it is encoded as a series of two uint16_t values.
27*3fc10f8cSRobert Mustacchi  *
28*3fc10f8cSRobert Mustacchi  * A value which is up to 20 bits (the current limit of the unicode code point
29*3fc10f8cSRobert Mustacchi  * space) is encoded by splitting it into two 10-bit values. The upper 10 bits
30*3fc10f8cSRobert Mustacchi  * are ORed with 0xd800 and the lower 10 bits are ORed with 0xdc00.
31*3fc10f8cSRobert Mustacchi  */
32*3fc10f8cSRobert Mustacchi 
33*3fc10f8cSRobert Mustacchi #ifdef __cplusplus
34*3fc10f8cSRobert Mustacchi extern "C" {
35*3fc10f8cSRobert Mustacchi #endif
36*3fc10f8cSRobert Mustacchi 
37*3fc10f8cSRobert Mustacchi /*
38*3fc10f8cSRobert Mustacchi  * Range of Unicode code points reserved for surrogate characters.
39*3fc10f8cSRobert Mustacchi  */
40*3fc10f8cSRobert Mustacchi #define	UNICODE_SUR_MIN		0xd800
41*3fc10f8cSRobert Mustacchi #define	UNICODE_SUR_MAX		0xdfff
42*3fc10f8cSRobert Mustacchi 
43*3fc10f8cSRobert Mustacchi /*
44*3fc10f8cSRobert Mustacchi  * Range of Unicode code points in supplementary planes.
45*3fc10f8cSRobert Mustacchi  */
46*3fc10f8cSRobert Mustacchi #define	UNICODE_SUP_START	0x10000
47*3fc10f8cSRobert Mustacchi #define	UNICODE_SUP_MAX		0x10ffff
48*3fc10f8cSRobert Mustacchi 
49*3fc10f8cSRobert Mustacchi /*
50*3fc10f8cSRobert Mustacchi  * Starting constants for surrogate pairs.
51*3fc10f8cSRobert Mustacchi  */
52*3fc10f8cSRobert Mustacchi #define	UNICODE_SUR_UPPER	0xd800
53*3fc10f8cSRobert Mustacchi #define	UNICODE_SUR_LOWER	0xdc00
54*3fc10f8cSRobert Mustacchi 
55*3fc10f8cSRobert Mustacchi /*
56*3fc10f8cSRobert Mustacchi  * Macros to extract the value from a surrogate pair and to take a code point
57*3fc10f8cSRobert Mustacchi  * and transform it into the surrogate version.
58*3fc10f8cSRobert Mustacchi  */
59*3fc10f8cSRobert Mustacchi #define	UNICODE_SUR_UVALUE(x)	(((x) & 0x3ff) << 10)
60*3fc10f8cSRobert Mustacchi #define	UNICODE_SUR_LVALUE(x)	((x) & 0x3ff)
61*3fc10f8cSRobert Mustacchi #define	UNICODE_SUR_UMASK(x)	(((x) >> 10) & 0x3ff)
62*3fc10f8cSRobert Mustacchi #define	UNICODE_SUR_LMASK(x)	((x) & 0x3ff)
63*3fc10f8cSRobert Mustacchi 
64*3fc10f8cSRobert Mustacchi #ifdef __cplusplus
65*3fc10f8cSRobert Mustacchi }
66*3fc10f8cSRobert Mustacchi #endif
67*3fc10f8cSRobert Mustacchi 
68*3fc10f8cSRobert Mustacchi #endif /* _UNICODE_H */
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