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authorThomas Voss <mail@thomasvoss.com> 2024-05-20 17:56:55 +0200
committerThomas Voss <mail@thomasvoss.com> 2024-05-20 17:56:55 +0200
commit2e125c1c7e75db14a88f0b8b09e61a132977c63e (patch)
tree30c37263315e07f983c2b05b69c17e47c827b849 /lib
parentd6b1db5c14ca1e731db299748d2df9eb955c9f7c (diff)
Support the 4 forms of Unicode string normalization
Diffstat (limited to 'lib')
-rw-r--r--lib/unicode/string/u8norm.c192
-rw-r--r--lib/unicode/string/u8norm_nfd.c94
-rw-r--r--lib/unicode/string/u8norm_nfkd.c94
3 files changed, 192 insertions, 188 deletions
diff --git a/lib/unicode/string/u8norm.c b/lib/unicode/string/u8norm.c
new file mode 100644
index 0000000..a918479
--- /dev/null
+++ b/lib/unicode/string/u8norm.c
@@ -0,0 +1,192 @@
+#include <string.h>
+
+#include "macros.h"
+#include "mbstring.h"
+#include "unicode/_cm.h"
+#include "unicode/prop.h"
+#include "unicode/string.h"
+
+#define BETWEEN(x, y, z) ((x) <= (y) && (y) <= (z))
+
+static void decomp(char8_t *, size_t *, size_t, rune, enum normtype);
+static void compbuf(char8_t *, size_t *);
+
+/* Computed using a gen/scale-norm.c */
+constexpr int NFD_SCALE = 3;
+constexpr int NFKD_SCALE = 11;
+
+/* For Hangul syllable decomposition */
+constexpr rune SBASE = 0xAC00;
+constexpr rune LBASE = 0x1100;
+constexpr rune VBASE = 0x1161;
+constexpr rune TBASE = 0x11A7;
+constexpr int LCNT = 19;
+constexpr int VCNT = 21;
+constexpr int TCNT = 28;
+constexpr int NCNT = VCNT * TCNT;
+constexpr int SCNT = LCNT * NCNT;
+
+char8_t *
+u8norm(size_t *dstn, struct u8view src, alloc_fn alloc, void *ctx,
+ enum normtype nt)
+{
+ ASSUME(dstn != nullptr);
+ ASSUME(alloc != nullptr);
+ ASSUME(BETWEEN(0, nt, 4));
+
+ /* Pre-allocate a buffer with some initial capacity; there is no need to
+ check for overflow when computing bufsz because alloc() will handle the
+ overflow error for us. */
+ int scale = (nt & 0b10) ? NFKD_SCALE : NFD_SCALE;
+ size_t bufsz = src.len * scale;
+ char8_t *dst = alloc(ctx, nullptr, 0, src.len, scale, alignof(char8_t));
+
+ *dstn = 0;
+ for (rune ch; ucsnext(&ch, &src) != 0; decomp(dst, dstn, bufsz, ch, nt))
+ ;
+ if (nt & 0b01)
+ compbuf(dst, dstn);
+ return alloc(ctx, dst, src.len, *dstn, 1, alignof(char8_t));
+}
+
+#define WRITE(ch) *dstn += rtoucs(dst + *dstn, bufsz - *dstn, (ch))
+
+void
+decomp(char8_t *dst, size_t *dstn, size_t bufsz, rune ch, enum normtype nt)
+{
+ if (uprop_get_hst(ch) != HST_NA) {
+ int si = ch - SBASE;
+ if (si < 0 || si > SCNT) {
+ WRITE(ch);
+ return;
+ }
+ rune l, v, t;
+ l = LBASE + si / NCNT;
+ v = VBASE + (si % NCNT) / TCNT;
+ t = TBASE + si % TCNT;
+ WRITE(l);
+ WRITE(v);
+ if (t != TBASE)
+ WRITE(t);
+ } else if (((nt & 0b10) && uprop_get_dt(ch) != DT_NONE)
+ || ((nt & 0b10) == 0 && uprop_get_dt(ch) == DT_CAN))
+ {
+ struct rview rv = uprop_get_dm(ch);
+ for (size_t i = 0; i < rv.len; i++)
+ decomp(dst, dstn, bufsz, rv.p[i], nt);
+ } else {
+ enum uprop_ccc ccc = uprop_get_ccc(ch);
+ if (ccc == CCC_NR) {
+ WRITE(ch);
+ return;
+ }
+
+ int w;
+ rune hc;
+ char8_t *p = dst + *dstn;
+ while (w = ucsprev(&hc, (const char8_t **)&p, dst)) {
+ enum uprop_ccc ccc2 = uprop_get_ccc(hc);
+ if (ccc2 == CCC_NR || ccc2 <= ccc) {
+out:
+ char8_t tmp[U8_LEN_MAX];
+ int w2 = rtoucs(tmp, sizeof(tmp), ch);
+ p += w;
+ memmove(p + w2, p, dst + *dstn - p);
+ memcpy(p, tmp, w2);
+ *dstn += w2;
+ return;
+ }
+ }
+
+ /* Loop didn’t early-return; append to the start */
+ goto out;
+ }
+}
+
+#undef WRITE
+
+/* The following implements the canonical composition algorithm, and it may be
+ useful to read it to understand what’s going on. It can be found under
+ §3.11 Normalization Forms of the Unicode standard, subsection ‘Canonical
+ Composition Algorithm’. */
+
+void
+compbuf(char8_t *dst, size_t *dstn)
+{
+ int wC, wL;
+ rune C, L;
+ struct u8view sv = {dst, *dstn};
+
+ while ((wL = ucsnext(&L, &sv)) != 0) {
+ if (uprop_get_ccc(L) != CCC_NR)
+ continue;
+ char8_t *after_L = (char8_t *)sv.p;
+
+ enum uprop_ccc prevcc = 0;
+ struct u8view sv_ = sv;
+
+ while ((wC = ucsnext(&C, &sv_)) != 0) {
+ enum uprop_ccc curcc = uprop_get_ccc(C);
+ bool blocked = curcc <= prevcc;
+
+ if (blocked) {
+ if (curcc != CCC_NR)
+ continue;
+ if (curcc != prevcc)
+ break;
+ }
+
+ prevcc = curcc;
+ rune comp = uprop_get_cm(L, C);
+
+ /* Try Hangul composition */
+ if (comp == 0) {
+ if (BETWEEN(LBASE, L, LBASE + LCNT - 1)
+ && BETWEEN(VBASE, C, VBASE + VCNT - 1))
+ {
+ comp = SBASE + ((L - LBASE) * NCNT + (C - VBASE) * TCNT);
+ } else if (BETWEEN(TBASE, C, TBASE + TCNT - 1)
+ && BETWEEN(SBASE, L, SBASE + SCNT - 1)
+ && ((L - SBASE) % TCNT) == 0)
+ {
+ comp = L + (C - TBASE);
+ }
+ }
+
+ if (comp != 0) {
+ char8_t *after_C = (char8_t *)sv_.p;
+
+ /* Shift bytes between L & C so that they’re contiguous with the
+ bytes after C */
+ memmove(after_L + wC, after_L, after_C - wC - after_L);
+
+ /* Write the composition into where L was */
+ int w = rtoucs(after_L - wL, wL + wC, comp);
+
+ /* Shift the bytes after L & C to be right after the new
+ composition */
+ memmove(after_L - wL + w, after_L + wC,
+ *dstn - (after_L + wC - dst));
+
+ /* Correct *dstn */
+ int shift = wL + wC - w;
+ *dstn -= shift;
+
+ /* Fix the inner string view */
+ sv_.p = after_C - shift;
+ sv_.len = *dstn - (sv_.p - dst);
+
+ /* Fix outer string view */
+ sv.p = sv.p - wL + w;
+ sv.len = *dstn - (sv.p - dst);
+ after_L = (char8_t *)sv.p;
+
+ /* Update the value of L */
+ L = comp;
+ wL = w;
+ prevcc = CCC_NR;
+ } else if (blocked)
+ break;
+ }
+ }
+}
diff --git a/lib/unicode/string/u8norm_nfd.c b/lib/unicode/string/u8norm_nfd.c
deleted file mode 100644
index a89a1b5..0000000
--- a/lib/unicode/string/u8norm_nfd.c
+++ /dev/null
@@ -1,94 +0,0 @@
-#include <string.h>
-
-#include "macros.h"
-#include "mbstring.h"
-#include "unicode/prop.h"
-#include "unicode/string.h"
-
-static void decomp(char8_t *, size_t *, size_t, rune);
-
-/* Computed using a gen/scale-norm.c */
-constexpr int NFD_SCALE = 3;
-
-/* For Hangul syllable decomposition */
-constexpr rune SBASE = 0xAC00;
-constexpr rune LBASE = 0x1100;
-constexpr rune VBASE = 0x1161;
-constexpr rune TBASE = 0x11A7;
-constexpr int LCNT = 19;
-constexpr int VCNT = 21;
-constexpr int TCNT = 28;
-constexpr int NCNT = VCNT * TCNT;
-constexpr int SCNT = LCNT * NCNT;
-
-char8_t *
-u8norm_nfd(size_t *dstn, struct u8view src, alloc_fn alloc, void *ctx)
-{
- ASSUME(dstn != nullptr);
- ASSUME(alloc != nullptr);
-
- /* Pre-allocate a buffer with some initial capacity; there is no need to
- check for overflow when computing bufsz because alloc() will handle the
- overflow error for us. */
- size_t bufsz = src.len * NFD_SCALE;
- char8_t *dst = alloc(ctx, nullptr, 0, src.len, NFD_SCALE, alignof(char8_t));
-
- *dstn = 0;
- for (rune ch; ucsnext(&ch, &src) != 0; decomp(dst, dstn, bufsz, ch))
- ;
- return alloc(ctx, dst, src.len, *dstn, 1, alignof(char8_t));
-}
-
-#define WRITE(ch) *dstn += rtoucs(dst + *dstn, bufsz - *dstn, (ch))
-
-void
-decomp(char8_t *dst, size_t *dstn, size_t bufsz, rune ch)
-{
- if (uprop_get_hst(ch) != HST_NA) {
- int si = ch - SBASE;
- if (si < 0 || si > SCNT) {
- WRITE(ch);
- return;
- }
- rune l, v, t;
- l = LBASE + si / NCNT;
- v = VBASE + (si % NCNT) / TCNT;
- t = TBASE + si % TCNT;
- WRITE(l);
- WRITE(v);
- if (t != TBASE)
- WRITE(t);
- } else if (uprop_get_dt(ch) == DT_CAN) {
- struct rview rv = uprop_get_dm(ch);
- for (size_t i = 0; i < rv.len; i++)
- decomp(dst, dstn, bufsz, rv.p[i]);
- } else {
- enum uprop_ccc ccc = uprop_get_ccc(ch);
- if (ccc == CCC_NR) {
- WRITE(ch);
- return;
- }
-
- int w;
- rune hc;
- char8_t *p = dst + *dstn;
- while (w = ucsprev(&hc, (const char8_t **)&p, dst)) {
- enum uprop_ccc ccc2 = uprop_get_ccc(hc);
- if (ccc2 == CCC_NR || ccc2 <= ccc) {
-out:
- char8_t tmp[U8_LEN_MAX];
- int w2 = rtoucs(tmp, sizeof(tmp), ch);
- p += w;
- memmove(p + w2, p, dst + *dstn - p);
- memcpy(p, tmp, w2);
- *dstn += w2;
- return;
- }
- }
-
- /* Loop didn’t early-return; append to the start */
- goto out;
- }
-}
-
-#undef WRITE
diff --git a/lib/unicode/string/u8norm_nfkd.c b/lib/unicode/string/u8norm_nfkd.c
deleted file mode 100644
index 898b650..0000000
--- a/lib/unicode/string/u8norm_nfkd.c
+++ /dev/null
@@ -1,94 +0,0 @@
-#include <string.h>
-
-#include "macros.h"
-#include "mbstring.h"
-#include "unicode/prop.h"
-#include "unicode/string.h"
-
-static void decomp(char8_t *, size_t *, size_t, rune);
-
-/* Computed using a gen/scale-norm.c */
-constexpr int NFKD_SCALE = 11;
-
-/* For Hangul syllable decomposition */
-constexpr rune SBASE = 0xAC00;
-constexpr rune LBASE = 0x1100;
-constexpr rune VBASE = 0x1161;
-constexpr rune TBASE = 0x11A7;
-constexpr int LCNT = 19;
-constexpr int VCNT = 21;
-constexpr int TCNT = 28;
-constexpr int NCNT = VCNT * TCNT;
-constexpr int SCNT = LCNT * NCNT;
-
-char8_t *
-u8norm_nfkd(size_t *dstn, struct u8view src, alloc_fn alloc, void *ctx)
-{
- ASSUME(dstn != nullptr);
- ASSUME(alloc != nullptr);
-
- /* Pre-allocate a buffer with some initial capacity; there is no need to
- check for overflow when computing bufsz because alloc() will handle the
- overflow error for us. */
- size_t bufsz = src.len * NFKD_SCALE;
- char8_t *dst = alloc(ctx, nullptr, 0, src.len, NFKD_SCALE, alignof(char8_t));
-
- *dstn = 0;
- for (rune ch; ucsnext(&ch, &src) != 0; decomp(dst, dstn, bufsz, ch))
- ;
- return alloc(ctx, dst, src.len, *dstn, 1, alignof(char8_t));
-}
-
-#define WRITE(ch) *dstn += rtoucs(dst + *dstn, bufsz - *dstn, (ch))
-
-void
-decomp(char8_t *dst, size_t *dstn, size_t bufsz, rune ch)
-{
- if (uprop_get_hst(ch) != HST_NA) {
- int si = ch - SBASE;
- if (si < 0 || si > SCNT) {
- WRITE(ch);
- return;
- }
- rune l, v, t;
- l = LBASE + si / NCNT;
- v = VBASE + (si % NCNT) / TCNT;
- t = TBASE + si % TCNT;
- WRITE(l);
- WRITE(v);
- if (t != TBASE)
- WRITE(t);
- } else if (uprop_get_dt(ch) != DT_NONE) {
- struct rview rv = uprop_get_dm(ch);
- for (size_t i = 0; i < rv.len; i++)
- decomp(dst, dstn, bufsz, rv.p[i]);
- } else {
- enum uprop_ccc ccc = uprop_get_ccc(ch);
- if (ccc == CCC_NR) {
- WRITE(ch);
- return;
- }
-
- int w;
- rune hc;
- char8_t *p = dst + *dstn;
- while (w = ucsprev(&hc, (const char8_t **)&p, dst)) {
- enum uprop_ccc ccc2 = uprop_get_ccc(hc);
- if (ccc2 == CCC_NR || ccc2 <= ccc) {
-out:
- char8_t tmp[U8_LEN_MAX];
- int w2 = rtoucs(tmp, sizeof(tmp), ch);
- p += w;
- memmove(p + w2, p, dst + *dstn - p);
- memcpy(p, tmp, w2);
- *dstn += w2;
- return;
- }
- }
-
- /* Loop didn’t early-return; append to the start */
- goto out;
- }
-}
-
-#undef WRITE