Add a function to iterate over all characters in a particular character

class. This is necessary in order to implement tr(1) efficiently in
multibyte locales, since the brute force method of finding all characters
in a class is infeasible with a 32-bit (or wider) wchar_t.

1 files changed, 90 insertions, 0 deletions

diff --git a/lib/libc/locale/nextwctype.c b/lib/libc/locale/nextwctype.c
new file mode 100644
index 000000000000..9363b0a700cc
--- /dev/null
+++ b/lib/libc/locale/nextwctype.c
@@ -0,0 +1,90 @@
+/*-
+ * Copyright (c) 2004 Tim J. Robbins.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <runetype.h>
+#include <wchar.h>
+#include <wctype.h>
+
+wint_t
+nextwctype(wint_t wc, wctype_t wct)
+{
+	size_t lim;
+	_RuneRange *rr = &_CurrentRuneLocale->__runetype_ext;
+	_RuneEntry *base, *re;
+	int noinc;
+
+	noinc = 0;
+	if (wc < _CACHED_RUNES) {
+		wc++;
+		while (wc < _CACHED_RUNES) {
+			if (_CurrentRuneLocale->__runetype[wc] & wct)
+				return (wc);
+			wc++;
+		}
+		wc--;
+	}
+	if (rr->__ranges != NULL && wc < rr->__ranges[0].__min) {
+		wc = rr->__ranges[0].__min;
+		noinc = 1;
+	}
+
+	/* Binary search -- see bsearch.c for explanation. */
+	base = rr->__ranges;
+	for (lim = rr->__nranges; lim != 0; lim >>= 1) {
+		re = base + (lim >> 1);
+		if (re->__min <= wc && wc <= re->__max)
+			goto found;
+		else if (wc > re->__max) {
+			base = re + 1;
+			lim--;
+		}
+	}
+	return (-1);
+found:
+	if (!noinc)
+		wc++;
+	if (re->__min <= wc && wc <= re->__max) {
+		if (re->__types != NULL) {
+			for (; wc <= re->__max; wc++)
+				if (re->__types[wc - re->__min] & wct)
+					return (wc);
+		} else if (re->__map & wct)
+			return (wc);
+	}
+	while (++re < rr->__ranges + rr->__nranges) {
+		wc = re->__min;
+		if (re->__types != NULL) {
+			for (; wc <= re->__max; wc++)
+				if (re->__types[wc - re->__min] & wct)
+					return (wc);
+		} else if (re->__map & wct)
+			return (wc);
+	}
+	return (-1);
+}