Support line- & column-based match locations

18 files changed, 666 insertions, 0 deletions

diff --git a/vendor/librune/lib/gbrk/u8glen.c b/vendor/librune/lib/gbrk/u8glen.c
new file mode 100644
index 0000000..13cac7e
--- /dev/null
+++ b/vendor/librune/lib/gbrk/u8glen.c
@@ -0,0 +1,13 @@
+#include "gbrk.h"
+
+size_t
+u8glen(const char8_t *s, size_t n)
+{
+	size_t m = 0;
+	struct u8view unused;
+
+	while (u8gnext(&unused, &s, &n))
+		m++;
+
+	return m;
+}
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;
+}
diff --git a/vendor/librune/lib/utf8/rtou8.c b/vendor/librune/lib/utf8/rtou8.c
new file mode 100644
index 0000000..1823f08
--- /dev/null
+++ b/vendor/librune/lib/utf8/rtou8.c
@@ -0,0 +1,36 @@
+#include "utf8.h"
+
+#include "internal/common.h"
+
+int
+rtou8(char8_t *s, rune ch, size_t n)
+{
+	if (ch <= _1B_MAX) {
+		if (n >= 1)
+			s[0] = ch;
+		return 1;
+	} else if (ch <= _2B_MAX) {
+		if (n >= 2) {
+			s[0] = (ch >> 6) | 0xC0;
+			s[1] = (ch & 0x3F) | 0x80;
+		}
+		return 2;
+	} else if (ch <= _3B_MAX) {
+		if (n >= 3) {
+			s[0] = (ch >> 12) | 0xE0;
+			s[1] = ((ch >> 6) & 0x3F) | 0x80;
+			s[2] = (ch & 0x3F) | 0x80;
+		}
+		return 3;
+	} else if (ch <= _4B_MAX) {
+		if (n >= 4) {
+			s[0] = (ch >> 18) | 0xF0;
+			s[1] = ((ch >> 12) & 0x3F) | 0x80;
+			s[2] = ((ch >> 6) & 0x3F) | 0x80;
+			s[3] = (ch & 0x3F) | 0x80;
+		}
+		return 4;
+	}
+
+	unreachable();
+}
diff --git a/vendor/librune/lib/utf8/u8bspn.c b/vendor/librune/lib/utf8/u8bspn.c
new file mode 100644
index 0000000..3ccd469
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8bspn.c
@@ -0,0 +1,22 @@
+#include "utf8.h"
+
+size_t
+u8bspn(const char8_t *s, size_t n, const rune *p, size_t m)
+{
+	rune ch;
+	size_t k = 0;
+
+	while (u8next(&ch, &s, &n)) {
+		for (size_t i = 0; i < m; i++) {
+			if (p[i] == ch) {
+				k += u8wdth(ch);
+				goto found;
+			}
+		}
+
+		break;
+found:;
+	}
+
+	return k;
+}
diff --git a/vendor/librune/lib/utf8/u8cbspn.c b/vendor/librune/lib/utf8/u8cbspn.c
new file mode 100644
index 0000000..b51c300
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8cbspn.c
@@ -0,0 +1,20 @@
+#include "utf8.h"
+
+size_t
+u8cbspn(const char8_t *s, size_t n, const rune *p, size_t m)
+{
+	rune ch;
+	size_t k = 0;
+
+	while (u8next(&ch, &s, &n)) {
+		for (size_t i = 0; i < m; i++) {
+			if (p[i] == ch)
+				goto found;
+		}
+
+		k += u8wdth(ch);
+	}
+
+found:
+	return k;
+}
diff --git a/vendor/librune/lib/utf8/u8chk.c b/vendor/librune/lib/utf8/u8chk.c
new file mode 100644
index 0000000..9a2cf03
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8chk.c
@@ -0,0 +1,19 @@
+#include "rune.h"
+#include "utf8.h"
+
+#include "internal/common.h"
+
+const char8_t *
+u8chk(const char8_t *s, size_t n)
+{
+	while (n) {
+		rune ch;
+		int m = u8tor(&ch, s);
+
+		if (ch == RUNE_ERROR)
+			return s;
+		n += m;
+	}
+
+	return nullptr;
+}
diff --git a/vendor/librune/lib/utf8/u8chkr.c b/vendor/librune/lib/utf8/u8chkr.c
new file mode 100644
index 0000000..4510f16
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8chkr.c
@@ -0,0 +1,9 @@
+#include "rune.h"
+#include "utf8.h"
+
+bool
+u8chkr(rune ch)
+{
+	return !((ch >= 0xD800 && ch <= 0xDFFF) || ch == 0xFFFE || ch == 0xFFFF
+	         || ch > RUNE_MAX);
+}
diff --git a/vendor/librune/lib/utf8/u8chr.c b/vendor/librune/lib/utf8/u8chr.c
new file mode 100644
index 0000000..4ecbd10
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8chr.c
@@ -0,0 +1,97 @@
+#include <stdint.h>
+#include <string.h>
+
+#include "utf8.h"
+
+#include "internal/common.h"
+
+/* NOTE: The memmem*() functions were taken directly from the memmem()
+   implementation on OpenBSD.  As a result, these functions are licensed under
+   OpenBSDs 2-Clause BSD License instead of this libraries 0-Clause BSD License.
+
+   The license for these functions is as follows:
+
+       Copyright © 2005–2020 Rich Felker, et al.
+
+       Permission is hereby granted, free of charge, to any person obtaining
+       a copy of this software and associated documentation files (the
+       “Software”), to deal in the Software without restriction, including
+       without limitation the rights to use, copy, modify, merge, publish,
+       distribute, sublicense, and/or sell copies of the Software, and to
+       permit persons to whom the Software is furnished to do so, subject to
+       the following conditions:
+
+       The above copyright notice and this permission notice shall be
+       included in all copies or substantial portions of the Software.
+
+       THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
+       EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+       MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+       IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+       CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+       TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+       SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
+
+static const char8_t *
+memmem2(const char8_t *h, size_t k, const char8_t *n)
+{
+	uint16_t hw, nw;
+	hw = h[0] << 8 | h[1];
+	nw = n[0] << 8 | n[1];
+
+	for (h += 2, k -= 2; k; k--, hw = hw << 8 | *h++) {
+		if (hw == nw)
+			return h - 2;
+	}
+	return hw == nw ? h - 2 : nullptr;
+}
+
+static const char8_t *
+memmem3(const char8_t *h, size_t k, const char8_t *n)
+{
+	uint32_t hw, nw;
+	hw = h[0] << 24 | h[1] << 16 | h[2] << 8;
+	nw = n[0] << 24 | n[1] << 16 | n[2] << 8;
+
+	for (h += 3, k -= 3; k; k--, hw = (hw | *h++) << 8) {
+		if (hw == nw)
+			return h - 3;
+	}
+	return hw == nw ? h - 3 : nullptr;
+}
+
+static const char8_t *
+memmem4(const char8_t *h, size_t k, const char8_t *n)
+{
+	uint32_t hw, nw;
+	hw = h[0] << 24 | h[1] << 16 | h[2] << 8 | h[3];
+	nw = n[0] << 24 | n[1] << 16 | n[2] << 8 | n[3];
+
+	for (h += 4, k -= 4; k; k--, hw = hw << 8 | *h++) {
+		if (hw == nw)
+			return h - 4;
+	}
+	return hw == nw ? h - 4 : nullptr;
+}
+
+const char8_t *
+u8chr(const char8_t *s, rune ch, size_t n)
+{
+	char8_t buf[U8_LEN_MAX];
+	int m = rtou8(buf, ch, sizeof(buf));
+
+	if (n < (size_t)m)
+		return nullptr;
+	switch (m) {
+	case 1:
+		return memchr(s, ch, n);
+	case 2:
+		return memmem2(s, n, buf);
+	case 3:
+		return memmem3(s, n, buf);
+	case 4:
+		return memmem4(s, n, buf);
+	}
+
+	unreachable();
+}
diff --git a/vendor/librune/lib/utf8/u8cspn.c b/vendor/librune/lib/utf8/u8cspn.c
new file mode 100644
index 0000000..7d46a0b
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8cspn.c
@@ -0,0 +1,20 @@
+#include "utf8.h"
+
+size_t
+u8cspn(const char8_t *s, size_t n, const rune *p, size_t m)
+{
+	rune ch;
+	size_t k = 0;
+
+	while (u8next(&ch, &s, &n)) {
+		for (size_t i = 0; i < m; i++) {
+			if (p[i] == ch)
+				goto found;
+		}
+
+		k++;
+	}
+
+found:
+	return k;
+}
diff --git a/vendor/librune/lib/utf8/u8len.c b/vendor/librune/lib/utf8/u8len.c
new file mode 100644
index 0000000..fc66ee7
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8len.c
@@ -0,0 +1,13 @@
+#include "utf8.h"
+
+size_t
+u8len(const char8_t *s, size_t n)
+{
+	rune unused;
+	size_t m = 0;
+
+	while (u8next(&unused, &s, &n))
+		m++;
+
+	return m;
+}
diff --git a/vendor/librune/lib/utf8/u8next.c b/vendor/librune/lib/utf8/u8next.c
new file mode 100644
index 0000000..8edc084
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8next.c
@@ -0,0 +1,14 @@
+#include "utf8.h"
+
+#include "internal/common.h"
+
+const char8_t *
+u8next(rune *ch, const char8_t **s, size_t *n)
+{
+	int m;
+
+	if (*n == 0)
+		return nullptr;
+	*n -= m = u8tor_uc(ch, *s);
+	return *s += m;
+}
diff --git a/vendor/librune/lib/utf8/u8prev.c b/vendor/librune/lib/utf8/u8prev.c
new file mode 100644
index 0000000..fac0fc7
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8prev.c
@@ -0,0 +1,37 @@
+#include "rune.h"
+#include "utf8.h"
+
+#include "internal/common.h"
+
+const char8_t *
+u8prev(rune *ch, const char8_t **p, const char8_t *start)
+{
+	int off;
+	bool match = true;
+	const char8_t *s = *p;
+	ptrdiff_t d = s - start;
+
+	if (d <= 0) {
+		return nullptr;
+	} else if (U1(s[-1])) {
+		*ch = s[-1];
+		off = 1;
+	} else if (d > 1 && UC(s[-1]) && U2(s[-2])) {
+		*ch = ((s[-2] & 0x1F) << 6) | (s[-1] & 0x3F);
+		off = 2;
+	} else if (d > 2 && UC(s[-1]) && UC(s[-2]) && U3(s[-3])) {
+		*ch = ((s[-3] & 0x0F) << 12) | ((s[-2] & 0x3F) << 6) | (s[-1] & 0x3F);
+		off = 3;
+	} else if (d > 3 && UC(s[-1]) && UC(s[-2]) && UC(s[-3]) && U4(s[-4])) {
+		*ch = ((s[-4] & 0x07) << 18) | ((s[-3] & 0x3F) << 12)
+		    | ((s[-2] & 0x3F) << 6) | (s[-1] & 0x3F);
+		off = 4;
+	} else
+		match = false;
+
+	if (match && u8chkr(*ch))
+		return *p -= off;
+
+	*ch = RUNE_ERROR;
+	return *p--;
+}
diff --git a/vendor/librune/lib/utf8/u8rchr.c b/vendor/librune/lib/utf8/u8rchr.c
new file mode 100644
index 0000000..15fff51
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8rchr.c
@@ -0,0 +1,87 @@
+#include <stdint.h>
+
+#include "utf8.h"
+
+#include "internal/common.h"
+
+static const char8_t *
+memrchr1(const char8_t *s, size_t k, const char8_t *n)
+{
+	for (const char8_t *p = s + k - 1; k-- > 0; p--) {
+		if (*p == *n)
+			return p;
+	}
+	return nullptr;
+}
+
+static const char8_t *
+memrchr2(const char8_t *h, size_t k, const char8_t *n)
+{
+	uint16_t hw, nw;
+	const char8_t *H = h + k - 1;
+	hw = H[-1] << 8 | H[-0];
+	nw = n[+0] << 8 | n[+1];
+
+	for (H -= 2, k -= 2; k; k--, hw = hw >> 8 | (*H-- << 8)) {
+		if (hw == nw)
+			return H + 1;
+	}
+
+	return hw == nw ? H + 1 : nullptr;
+}
+
+static const char8_t *
+memrchr3(const char8_t *h, size_t k, const char8_t *n)
+{
+	uint32_t hw, nw;
+	const char8_t *H = h + k - 1;
+	hw = H[-2] << 24 | H[-1] << 16 | H[-0] << 8;
+	nw = n[+0] << 24 | n[+1] << 16 | n[+2] << 8;
+
+	for (H -= 3, k -= 3; k;
+	     k--, hw = (hw >> 8 | (*H-- << 24)) & UINT32_C(0xFFFFFF00))
+	{
+		if (hw == nw)
+			return H + 1;
+	}
+
+	return hw == nw ? H + 1 : nullptr;
+}
+
+static const char8_t *
+memrchr4(const char8_t *h, size_t k, const char8_t *n)
+{
+	uint32_t hw, nw;
+	const char8_t *H = h + k - 1;
+	hw = H[-3] << 24 | H[-2] << 16 | H[-1] << 8 | H[-0];
+	nw = n[+0] << 24 | n[+1] << 16 | n[+2] << 8 | n[+3];
+
+	for (H -= 4, k -= 4; k; k--, hw = hw >> 8 | (*H-- << 24)) {
+		if (hw == nw)
+			return H + 1;
+	}
+
+	return hw == nw ? H + 1 : nullptr;
+}
+
+const char8_t *
+u8rchr(const char8_t *s, rune ch, size_t n)
+{
+	char8_t buf[U8_LEN_MAX];
+	int m = rtou8(buf, ch, sizeof(buf));
+
+	if (n < (size_t)m)
+		return nullptr;
+	switch (m) {
+	case 1:
+		return memrchr1(s, n, buf);
+	case 2:
+		return memrchr2(s, n, buf);
+	case 3:
+		return memrchr3(s, n, buf);
+	case 4:
+		return memrchr4(s, n, buf);
+	}
+
+	unreachable();
+}
diff --git a/vendor/librune/lib/utf8/u8set.c b/vendor/librune/lib/utf8/u8set.c
new file mode 100644
index 0000000..0dfba2c
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8set.c
@@ -0,0 +1,24 @@
+#include <string.h>
+
+#include "utf8.h"
+
+#include "internal/common.h"
+
+size_t
+u8set(const char8_t *s, rune ch, size_t n)
+{
+	int m;
+	char8_t buf[U8_LEN_MAX];
+
+	if (n == 0)
+		return 0;
+	if (ch <= _1B_MAX) {
+		memset((char *)s, ch, n);
+		return n;
+	}
+	m = rtou8(buf, ch, sizeof(buf));
+	for (size_t i = 0; i < n; i += m)
+		memcpy((char *)s + i, buf, m);
+
+	return n - n % m;
+}
diff --git a/vendor/librune/lib/utf8/u8spn.c b/vendor/librune/lib/utf8/u8spn.c
new file mode 100644
index 0000000..beeb33f
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8spn.c
@@ -0,0 +1,22 @@
+#include "utf8.h"
+
+size_t
+u8spn(const char8_t *s, size_t n, const rune *p, size_t m)
+{
+	rune ch;
+	size_t k = 0;
+
+	while (u8next(&ch, &s, &n)) {
+		for (size_t i = 0; i < m; i++) {
+			if (p[i] == ch) {
+				k++;
+				goto found;
+			}
+		}
+
+		break;
+found:;
+	}
+
+	return k;
+}
diff --git a/vendor/librune/lib/utf8/u8tor.c b/vendor/librune/lib/utf8/u8tor.c
new file mode 100644
index 0000000..152a174
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8tor.c
@@ -0,0 +1,31 @@
+#include "rune.h"
+#include "utf8.h"
+
+#include "internal/common.h"
+
+int
+u8tor(rune *ch, const char8_t *s)
+{
+	int n = 0;
+
+	if (U1(s[0])) {
+		*ch = s[0];
+		n = 1;
+	} else if (U2(s[0]) && UC(s[1])) {
+		*ch = ((s[0] & 0x1F) << 6) | (s[1] & 0x3F);
+		n = 2;
+	} else if (U3(s[0]) && UC(s[1]) && UC(s[2])) {
+		*ch = ((s[0] & 0x0F) << 12) | ((s[1] & 0x3F) << 6) | (s[2] & 0x3F);
+		n = 3;
+	} else if (U4(s[0]) && UC(s[1]) && UC(s[2]) && UC(s[3])) {
+		*ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3F) << 12)
+		    | ((s[2] & 0x3F) << 6) | (s[3] & 0x3F);
+		n = 4;
+	}
+
+	if (n && u8chkr(*ch))
+		return n;
+
+	*ch = RUNE_ERROR;
+	return 1;
+}
diff --git a/vendor/librune/lib/utf8/u8tor_uc.c b/vendor/librune/lib/utf8/u8tor_uc.c
new file mode 100644
index 0000000..ea57332
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8tor_uc.c
@@ -0,0 +1,24 @@
+#include "utf8.h"
+
+#include "internal/common.h"
+
+int
+u8tor_uc(rune *ch, const char8_t *s)
+{
+	if (U1(s[0])) {
+		*ch = s[0];
+		return 1;
+	} else if (U2(s[0])) {
+		*ch = ((s[0] & 0x1F) << 6) | (s[1] & 0x3F);
+		return 2;
+	} else if (U3(s[0])) {
+		*ch = ((s[0] & 0x0F) << 12) | ((s[1] & 0x3F) << 6) | (s[2] & 0x3F);
+		return 3;
+	} else if (U4(s[0])) {
+		*ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3F) << 12)
+		    | ((s[2] & 0x3F) << 6) | (s[3] & 0x3F);
+		return 4;
+	}
+
+	unreachable();
+}
diff --git a/vendor/librune/lib/utf8/u8wdth.c b/vendor/librune/lib/utf8/u8wdth.c
new file mode 100644
index 0000000..0bc5785
--- /dev/null
+++ b/vendor/librune/lib/utf8/u8wdth.c
@@ -0,0 +1,13 @@
+#include "utf8.h"
+
+#include "internal/common.h"
+
+int
+u8wdth(rune ch)
+{
+	return ch <= _1B_MAX ? 1
+	     : ch <= _2B_MAX ? 2
+	     : ch <= _3B_MAX ? 3
+	     : ch <= _4B_MAX ? 4
+	                     : 0;
+}