diff options
author | Thomas Voss <mail@thomasvoss.com> | 2024-01-21 03:03:58 +0100 |
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committer | Thomas Voss <mail@thomasvoss.com> | 2024-01-21 03:03:58 +0100 |
commit | 4f93f935dc7a981ca073a322425c3f5929ffb644 (patch) | |
tree | 4460586408ec7fdfcecf3ba4584f0435067125a6 /vendor/librune/lib/gbrk/u8gnext.c | |
parent | 72ea25a4d73e3e026366d4165f5bc4ec9e7418cb (diff) |
Support line- & column-based match locations
Diffstat (limited to 'vendor/librune/lib/gbrk/u8gnext.c')
-rw-r--r-- | vendor/librune/lib/gbrk/u8gnext.c | 165 |
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; +} |