1 files changed, 56 insertions, 0 deletions
diff --git a/src/core/utf8.h b/src/core/utf8.h
new file mode 100644
index 00000000..5bb53193
--- /dev/null
+++ b/src/core/utf8.h
@@ -0,0 +1,56 @@
+#ifndef __UTF8_H
+#define __UTF8_H
+
+/* XXX I didn't check the encoding range of big5+. This is standard big5. */
+#define is_big5_los(lo) (0x40 <= (lo) && (lo) <= 0x7E) /* standard */
+#define is_big5_lox(lo) (0x80 <= (lo) && (lo) <= 0xFE) /* extended */
+#define is_big5_lo(lo)	((is_big5_los(lo) || is_big5_lox(lo)))
+#define is_big5_hi(hi)  (0x81 <= (hi) && (hi) <= 0xFE)
+#define is_big5(hi,lo) (is_big5_hi(hi) && is_big5_lo(lo))
+
+#include <glib.h>
+typedef guint32 unichar;
+
+/* Returns width for character (0-2). */
+int mk_wcwidth(unichar c);
+
+/* Advance the str pointer one character further; return the number of columns
+ * occupied by the skipped character.
+ */
+int string_advance(char const **str, int policy);
+
+/* TREAT_STRING_AS_BYTES means strings are to be treated using strncpy,
+ * strnlen, etc.
+ * TREAT_STRING_AS_UTF8 means strings are to be treated using g_utf8_*
+ * functions.
+ */
+enum str_policy {
+	TREAT_STRING_AS_BYTES,
+	TREAT_STRING_AS_UTF8
+};
+
+/* Return how the str string ought to be treated: TREAT_STRING_AS_UTF8 if the
+ * terminal handles UTF-8 and if the string appears to be a valid UTF-8 string;
+ * TREAT_STRING_AS_BYTES otherwise.
+ */
+int string_policy(const char *str);
+
+/* Return the length of the str string according to the given policy; if policy
+ * is -1, this function will call string_policy().
+ */
+int string_length(const char *str, int policy);
+/* Return the screen width of the str string according to the given policy; if
+ * policy is -1, this function will call string_policy().
+ */
+int string_width(const char *str, int policy);
+
+/* Return the amount of characters from str it takes to reach n columns, or -1 if
+ * str is NULL. Optionally return the equivalent amount of bytes.
+ * If policy is -1, this function will call string_policy().
+ */
+int string_chars_for_width(const char *str, int policy, unsigned int n, unsigned int *bytes);
+
+#define unichar_isprint(c) (((c) & ~0x80) >= 32)
+#define is_utf8_leading(c) (((c) & 0xc0) != 0x80)
+
+#endif