1 files changed, 176 insertions, 0 deletions
diff --git a/utf8.c b/utf8.c
new file mode 100644
index 0000000..13c5fe6
--- /dev/null
+++ b/utf8.c
@@ -0,0 +1,176 @@
+/* -----------------------------------------------------------------------------
+ * Utility functions
+ * ---------------------------------------------------------------------------*/
+
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include "utf8.h"
+
+/* This one is always implemented */
+int utf8_fromunicode(char *p, unsigned short uc)
+{
+    if (uc <= 0x7f) {
+        *p = uc;
+        return 1;
+    }
+    else if (uc <= 0x7ff) {
+        *p++ = 0xc0 | ((uc & 0x7c0) >> 6);
+        *p = 0x80 | (uc & 0x3f);
+        return 2;
+    }
+    else {
+        *p++ = 0xe0 | ((uc & 0xf000) >> 12);
+        *p++ = 0x80 | ((uc & 0xfc0) >> 6);
+        *p = 0x80 | (uc & 0x3f);
+        return 3;
+    }
+}
+
+#ifdef JIM_UTF8
+int utf8_charlen(int c)
+{
+    if ((c & 0x80) == 0) {
+        return 1;
+    }
+    if ((c & 0xe0) == 0xc0) {
+        return 2;
+    }
+    if ((c & 0xf0) == 0xe0) {
+        return 3;
+    }
+    if ((c & 0xf8) == 0xf0) {
+        return 4;
+    }
+    /* Invalid sequence */
+    return -1;
+}
+
+int utf8_strlen(const char *str, int bytelen)
+{
+    int charlen = 0;
+    if (bytelen < 0) {
+        bytelen = strlen(str);
+    }
+    while (bytelen) {
+        int c;
+        int l = utf8_tounicode(str, &c);
+        charlen++;
+        str += l;
+        bytelen -= l;
+    }
+    return charlen;
+}
+
+int utf8_index(const char *str, int index)
+{
+    const char *s = str;
+    while (index--) {
+        int c;
+        s += utf8_tounicode(s, &c);
+    }
+    return s - str;
+}
+
+int utf8_charequal(const char *s1, const char *s2)
+{
+    int c1, c2;
+
+    utf8_tounicode(s1, &c1);
+    utf8_tounicode(s2, &c2);
+
+    return c1 == c2;
+}
+
+int utf8_tounicode(const char *str, int *uc)
+{
+    unsigned const char *s = (unsigned const char *)str;
+
+    if (s[0] < 0xc0) {
+        *uc = s[0];
+        return 1;
+    }
+    if (s[0] < 0xe0) {
+        if ((s[1] & 0xc0) == 0x80) {
+            *uc = ((s[0] & ~0xc0) << 6) | (s[1] & ~0x80);
+            return 2;
+        }
+    }
+    else if (s[0] < 0xf0) {
+        if (((str[1] & 0xc0) == 0x80) && ((str[2] & 0xc0) == 0x80)) {
+            *uc = ((s[0] & ~0xe0) << 12) | ((s[1] & ~0x80) << 6) | (s[2] & ~0x80);
+            return 3;
+        }
+    }
+
+    /* Invalid sequence, so just return the byte */
+    *uc = *s;
+    return 1;
+}
+
+struct casemap {
+    unsigned short code;    /* code point */
+    signed char lowerdelta; /* add for lowercase, or if -128 use the ext table */
+    signed char upperdelta; /* add for uppercase, or offset into the ext table */
+};
+
+/* Extended table for codepoints where |delta| > 127 */
+struct caseextmap {
+    unsigned short lower;
+    unsigned short upper;
+};
+
+/* Generated mapping tables */
+#include "unicode_mapping.c"
+
+#define NUMCASEMAP sizeof(unicode_case_mapping) / sizeof(*unicode_case_mapping)
+
+static int cmp_casemap(const void *key, const void *cm)
+{
+    return *(int *)key - (int)((const struct casemap *)cm)->code;
+}
+
+int utf8_upper(int uc)
+{
+    const struct casemap *cm;
+
+    if (isascii(uc)) {
+        return toupper(uc);
+    }
+
+    cm = bsearch(&uc, unicode_case_mapping, NUMCASEMAP, sizeof(*unicode_case_mapping), cmp_casemap);
+
+    if (cm) {
+        if (cm->lowerdelta == -128) {
+            uc = unicode_extmap[cm->upperdelta].upper;
+        }
+        else {
+            uc += cm->upperdelta;
+        }
+    }
+    return uc;
+}
+
+int utf8_lower(int uc)
+{
+    const struct casemap *cm;
+
+    if (isascii(uc)) {
+        return tolower(uc);
+    }
+
+    cm = bsearch(&uc, unicode_case_mapping, NUMCASEMAP, sizeof(*unicode_case_mapping), cmp_casemap);
+
+    if (cm) {
+        if (cm->lowerdelta == -128) {
+            uc = unicode_extmap[cm->upperdelta].lower;
+        }
+        else {
+            uc += cm->lowerdelta;
+        }
+    }
+    return uc;
+}
+
+#endif