[utf8] Adding method to get the script of a string and the length of the span (rolls Common script up with the previuos script)

src/unicode_scripts.c

@@ -2,11 +2,47 @@
 
 #include "unicode_scripts_data.c"
 
-script_t get_char_script(uint32_t ch) {
+inline script_t get_char_script(uint32_t ch) {
-    if (ch > NUM_CHARS - 1) return SCRIPT_UNKNOWN;
+    if (ch > NUM_CODEPOINTS - 1) return SCRIPT_UNKNOWN;
     return char_scripts[ch];
 }
 
-script_languages_t get_script_languages(script_t script) {
+inline script_languages_t get_script_languages(script_t script) {
     return script_languages[script];
+}
+
+script_t string_script(char *str, size_t *len) {
+    int32_t ch;
+    script_t last_script = SCRIPT_UNKNOWN;
+    script_t script = SCRIPT_UNKNOWN;
+
+    uint8_t *ptr = (uint8_t *)str;
+
+    *len = 0;
+
+    while (1) {
+        ssize_t char_len = utf8proc_iterate(ptr, -1, &ch);
+
+        if (ch == 0) break;
+
+        script = get_char_script((uint32_t)ch);
+
+        if (script == SCRIPT_COMMON) {
+            script = last_script;
+        }
+
+        if (last_script != script && last_script != SCRIPT_UNKNOWN) {
+            break;
+        }
+
+        ptr += char_len;
+        *len += char_len;
+
+        if (script != SCRIPT_UNKNOWN || script != SCRIPT_COMMON) {
+            last_script = script;
+        }
+    
+    }
+
+    return last_script;
 }

src/unicode_scripts.h

@@ -2,6 +2,7 @@
 #define UNICODE_SCRIPTS_H
 
 #include <stdlib.h>
+#include "utf8proc/utf8proc.h"
 #include "unicode_script_types.h"
 
 typedef struct script_code {
@@ -17,4 +18,6 @@ typedef struct script_languages {
 script_t get_char_script(uint32_t ch);
 script_languages_t get_script_languages(script_t script);
 
+script_t string_script(char *str, size_t *len);
+
 #endif