aboutsummaryrefslogtreecommitdiff
path: root/lib/unicode/string/u8title.c
blob: c0637ff0c05ee44edd104b898b342e6b00c62c49 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
#include <errno.h>
#include <stdckdint.h>

#include "_attrs.h"
#include "alloc.h"
#include "macros.h"
#include "mbstring.h"
#include "unicode/prop.h"
#include "unicode/string.h"

constexpr rune COMB_DOT_ABOVE = 0x0307;

[[unsequenced, _mlib_inline]]
static inline bool
uprop_ccc_0_or_230(rune ch)
{
	enum uprop_ccc x = uprop_get_ccc(ch);
	return x == 0 || x == 230;
}

char8_t *
u8title(size_t *dstn, u8view_t sv, caseflags_t flags, allocator_t mem)
{
	ASSUME(dstn != nullptr);

	struct tcctx ctx_t;
	struct lcctx ctx_l;

	ctx_t.az_or_tr = ctx_l.az_or_tr = flags & CF_LANG_AZ;
	ctx_t.lt = ctx_l.lt = flags & CF_LANG_LT;

	rune ch;
	bool nl_IJ = false;
	size_t n, before_dot_cnt, more_above_cnt;
	u8view_t word = {}, wcpy = sv;
	struct {
		bool before;
		size_t after;
	} final_sigma = {};
	enum {
		TITLE,
		BETWEEN,
		LOWER,
	} state = 0;

	n = before_dot_cnt = more_above_cnt = 0;

	size_t bufsz;
	if (ckd_mul(&bufsz, sv.len, (size_t)U8TITLE_SCALE)) {
		errno = EOVERFLOW;
		return nullptr;
	}

	char8_t *dst = new(mem, typeof(*dst), bufsz);

	while (u8next(&ch, &sv)) {
		if (sv.p > word.p + word.len) {
			u8wnext(&word, &wcpy);
			ctx_t.after_soft_dotted = false;
			state = TITLE;
		}

		if (ctx_l.az_or_tr || ctx_l.lt) {
			if (before_dot_cnt == 0 || more_above_cnt == 0) {
				rune ch = 0;
				before_dot_cnt = more_above_cnt = 0;
				u8view_t cpy = sv;

				do {
					before_dot_cnt++;
					more_above_cnt++;
				} while (u8next(&ch, &cpy) && !uprop_ccc_0_or_230(ch));

				if (ch != COMB_DOT_ABOVE)
					before_dot_cnt = 0;
				if (uprop_get_ccc(ch) != 230)
					more_above_cnt = 0;
			} else {
				before_dot_cnt--;
				more_above_cnt--;
			}
		}

		if (final_sigma.after == 0) {
			rune ch = 0;
			u8view_t cpy = sv;

			do
				final_sigma.after++;
			while (u8next(&ch, &cpy) && uprop_is_ci(ch));

			if (!uprop_is_cased(ch))
				final_sigma.after = 0;
		} else
			final_sigma.after--;

		ctx_l.before_dot = before_dot_cnt > 0;
		ctx_l.more_above = more_above_cnt > 0;
		ctx_l.final_sigma = final_sigma.before && final_sigma.after == 0;

		if (state == BETWEEN && uprop_is_cased(ch))
			state = LOWER;
		struct rview rv = state == LOWER && !nl_IJ ? uprop_get_lc(ch, ctx_l)
		                                           : uprop_get_tc(ch, ctx_t);
		if (nl_IJ)
			nl_IJ = false;
		if (state == TITLE && uprop_is_cased(ch)) {
			state = BETWEEN;

			if (flags & CF_LANG_NL) {
				rune next = 0;
				if (sv.len > 0)
					u8tor(&next, sv.p);
				nl_IJ = (ch == 'i' || ch == 'I')
				     && (next == 'j' || next == 'J');
			}
		}

		for (size_t i = 0; i < rv.len; i++)
			n += rtou8(dst + n, bufsz - n, rv.p[i]);

		ctx_l.after_I = (ch == 'I')
		             || (ctx_l.after_I && !uprop_ccc_0_or_230(ch));
		if (uprop_is_cased(ch))
			final_sigma.before = true;
		else if (!uprop_is_ci(ch))
			final_sigma.before = false;

		if (uprop_is_sd(ch))
			ctx_t.after_soft_dotted = true;
		else if (uprop_ccc_0_or_230(ch))
			ctx_t.after_soft_dotted = false;
	}

	*dstn = n;
	return resz(mem, dst, bufsz, n);
}