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Diffstat (limited to 'vendor/librune/lib/gbrk/u8gnext.c')
-rw-r--r--vendor/librune/lib/gbrk/u8gnext.c165
1 files changed, 165 insertions, 0 deletions
diff --git a/vendor/librune/lib/gbrk/u8gnext.c b/vendor/librune/lib/gbrk/u8gnext.c
new file mode 100644
index 0000000..875d5cb
--- /dev/null
+++ b/vendor/librune/lib/gbrk/u8gnext.c
@@ -0,0 +1,165 @@
+#include <sys/types.h>
+
+#include "gbrk.h"
+#include "utf8.h"
+
+#include "internal/common.h"
+#include "internal/gbrk_lookup.h"
+
+#define lengthof(a) (sizeof(a) / sizeof(*(a)))
+
+struct gbrk_state {
+ enum {
+ GB9C_NONE,
+ GB9C_CNSNT,
+ GB9C_LNK,
+ } gb9c;
+ bool gb11 : 1;
+ bool gb12 : 1;
+};
+
+static bool u8isgbrk(rune, rune, struct gbrk_state *);
+static gbrk_prop getprop(rune);
+
+const char8_t *
+u8gnext(struct u8view *g, const char8_t **s, size_t *n)
+{
+ int m;
+ rune ch1;
+ const char8_t *p;
+ struct gbrk_state gs = {0};
+
+ if (*n == 0)
+ return nullptr;
+
+ g->p = p = *s;
+ p += u8tor_uc(&ch1, p);
+
+ for (;;) {
+ rune ch2;
+
+ if ((size_t)(p - *s) >= *n)
+ ch2 = 0;
+ else
+ m = u8tor_uc(&ch2, p);
+ if (u8isgbrk(ch1, ch2, &gs)) {
+ *n -= g->len = p - *s;
+ return *s = p;
+ }
+
+ ch1 = ch2;
+ p += m;
+ }
+}
+
+bool
+u8isgbrk(rune a, rune b, struct gbrk_state *gs)
+{
+ gbrk_prop ap, bp;
+
+ /* GB1 & GB2 */
+ if (!a || !b)
+ goto do_break;
+
+ /* GB3 & ASCII fast-track */
+ if ((a | b) < 0x300) {
+ if (a == '\r' && b == '\n')
+ return false;
+ goto do_break;
+ }
+
+ /* GB4 */
+ if (a == '\r' || a == '\n' || ((ap = getprop(a)) & GBP_CTRL))
+ goto do_break;
+
+ /* GB5 */
+ if (b == '\r' || b == '\n' || ((bp = getprop(b)) & GBP_CTRL))
+ goto do_break;
+
+ /* Setting flags for GB9c */
+ if (ap & GBP_INDC_CNSNT)
+ gs->gb9c = GB9C_CNSNT;
+ else if ((ap & GBP_INDC_LNK) && gs->gb9c == GB9C_CNSNT)
+ gs->gb9c = GB9C_LNK;
+
+ /* GB6 */
+ if ((ap & GBP_HNGL_L)
+ && (bp & (GBP_HNGL_L | GBP_HNGL_V | GBP_HNGL_LV | GBP_HNGL_LVT)))
+ {
+ return false;
+ }
+
+ /* GB7 */
+ if ((ap & (GBP_HNGL_LV | GBP_HNGL_V)) && (bp & (GBP_HNGL_V | GBP_HNGL_T)))
+ return false;
+
+ /* GB8 */
+ if ((ap & (GBP_HNGL_LVT | GBP_HNGL_T)) && (bp & GBP_HNGL_T))
+ return false;
+
+ /* GB9 */
+ if (bp & (GBP_EXT | GBP_ZWJ)) {
+ if (ap & GBP_PIC)
+ gs->gb11 = true;
+ return false;
+ }
+
+ /* GB9a */
+ if (bp & GBP_SM)
+ return false;
+
+ /* GB9b */
+ if (ap & GBP_PREP)
+ return false;
+
+ /* GB9c */
+ if ((ap & (GBP_INDC_EXT | GBP_INDC_LNK)) && (bp & GBP_INDC_CNSNT)
+ && gs->gb9c == GB9C_LNK)
+ {
+ return false;
+ }
+
+ /* GB11 */
+ if (gs->gb11) {
+ if ((ap & GBP_EXT) && (bp & (GBP_EXT | GBP_ZWJ)))
+ return false;
+ if ((ap & GBP_ZWJ) && (bp & GBP_PIC))
+ return false;
+ }
+
+ /* GB12 & GB13 */
+ if (ap & GBP_RI) {
+ if (gs->gb12 || !(bp & GBP_RI))
+ goto do_break;
+ gs->gb12 = true;
+ return false;
+ }
+
+ /* GB999 */
+do_break:
+ gs->gb9c = GB9C_NONE;
+ gs->gb11 = gs->gb12 = false;
+ return true;
+}
+
+gbrk_prop
+getprop(rune ch)
+{
+ ssize_t lo, hi;
+
+ lo = 0;
+ hi = lengthof(gbrk_prop_tbl) - 1;
+
+ while (lo <= hi) {
+ ssize_t i = (lo + hi) / 2;
+
+ if (ch < gbrk_prop_tbl[i].lo)
+ hi = i - 1;
+ else if (ch > gbrk_prop_tbl[i].hi)
+ lo = i + 1;
+ else
+ return gbrk_prop_tbl[i].prop;
+ }
+
+ return GBP_OTHER;
+}