api: add new functions strcasecmp_range and strncasecmp_range

src/core/wee-string.c

@@ -138,6 +138,37 @@ string_strcasecmp (const char *string1, const char *string2)
     return (string1[0]) ? 1 : ((string2[0]) ? -1 : 0);
 }
 
+/*
+ * string_strcasecmp_range: locale and case independent string comparison
+ *                          using range to compare case:
+ *                          - range = 26: A-Z         ==> a-z
+ *                          - range = 29: A-Z [ \ ]   ==> a-z { | }
+ *                          - range = 30: A-Z [ \ ] ^ ==> a-z { | } ~
+ *                          (ranges 29 and 30 are used by some protocols like
+ *                          IRC)
+ */
+
+int
+string_strcasecmp_range (const char *string1, const char *string2, int range)
+{
+    int diff;
+
+    if (!string1 || !string2)
+        return (string1) ? 1 : ((string2) ? -1 : 0);
+
+    while (string1[0] && string2[0])
+    {
+        diff = utf8_charcasecmp_range (string1, string2, range);
+        if (diff != 0)
+            return diff;
+
+        string1 = utf8_next_char (string1);
+        string2 = utf8_next_char (string2);
+    }
+
+    return (string1[0]) ? 1 : ((string2[0]) ? -1 : 0);
+}
+
 /*
  * string_strncasecmp: locale and case independent string comparison
  *                     with max length
@@ -169,6 +200,43 @@ string_strncasecmp (const char *string1, const char *string2, int max)
         return (string1[0]) ? 1 : ((string2[0]) ? -1 : 0);
 }
 
+/*
+ * string_strncasecmp_range: locale and case independent string comparison
+ *                           with max length, using range to compare case:
+ *                           - range = 26: A-Z         ==> a-z
+ *                           - range = 29: A-Z [ \ ]   ==> a-z { | }
+ *                           - range = 30: A-Z [ \ ] ^ ==> a-z { | } ~
+ *                           (ranges 29 and 30 are used by some protocols like
+ *                           IRC)
+ */
+
+int
+string_strncasecmp_range (const char *string1, const char *string2, int max,
+                          int range)
+{
+    int count, diff;
+
+    if (!string1 || !string2)
+        return (string1) ? 1 : ((string2) ? -1 : 0);
+
+    count = 0;
+    while ((count < max) && string1[0] && string2[0])
+    {
+        diff = utf8_charcasecmp_range (string1, string2, range);
+        if (diff != 0)
+            return diff;
+
+        string1 = utf8_next_char (string1);
+        string2 = utf8_next_char (string2);
+        count++;
+    }
+
+    if (count >= max)
+        return 0;
+    else
+        return (string1[0]) ? 1 : ((string2[0]) ? -1 : 0);
+}
+
 /*
  * string_strcmp_ignore_chars: compare 2 strings, ignoring ignore some chars
  */

src/core/wee-string.h

@@ -28,8 +28,12 @@ extern char *string_strndup (const char *string, int length);
 extern void string_tolower (char *string);
 extern void string_toupper (char *string);
 extern int string_strcasecmp (const char *string1, const char *string2);
+extern int string_strcasecmp_range (const char *string1, const char *string2,
+                                    int range);
 extern int string_strncasecmp (const char *string1, const char *string2,
                                int max);
+extern int string_strncasecmp_range (const char *string1, const char *string2,
+                                     int max, int range);
 extern int string_strcmp_ignore_chars (const char *string1,
                                        const char *string2,
                                        const char *chars_ignored,

src/core/wee-utf8.c

@@ -470,6 +470,35 @@ utf8_charcasecmp (const char *string1, const char *string2)
     return (wchar1 < wchar2) ? -1 : ((wchar1 == wchar2) ? 0 : 1);
 }
 
+/*
+ * utf8_charcasecmp_range: compare two utf8 chars, case is ignored
+ *                         using a range, examples:
+ *                         - range = 26: A-Z         ==> a-z
+ *                         - range = 29: A-Z [ \ ]   ==> a-z { | }
+ *                         - range = 30: A-Z [ \ ] ^ ==> a-z { | } ~
+ *                         (ranges 29 and 30 are used by some protocols like
+ *                         IRC)
+ */
+
+int
+utf8_charcasecmp_range (const char *string1, const char *string2, int range)
+{
+    wint_t wchar1, wchar2;
+
+    if (!string1 || !string2)
+        return (string1) ? 1 : ((string2) ? -1 : 0);
+
+    wchar1 = utf8_wide_char (string1);
+    if ((wchar1 >= 'A') && (wchar1 < 'A' + (unsigned int)range))
+        wchar1 += ('a' - 'A');
+
+    wchar2 = utf8_wide_char (string2);
+    if ((wchar2 >= 'A') && (wchar2 < 'A' + (unsigned int)range))
+        wchar2 += ('a' - 'A');
+
+    return (wchar1 < wchar2) ? -1 : ((wchar1 == wchar2) ? 0 : 1);
+}
+
 /*
  * utf8_char_size_screen: return number of chars needed on screen to display
  *                        UTF-8 char

src/core/wee-utf8.h

@@ -46,6 +46,8 @@ extern int utf8_strnlen (const char *string, int bytes);
 extern int utf8_strlen_screen (const char *string);
 extern int utf8_charcmp (const char *string1, const char *string2);
 extern int utf8_charcasecmp (const char *string1, const char *string2);
+extern int utf8_charcasecmp_range (const char *string1, const char *string2,
+                                   int range);
 extern int utf8_char_size_screen (const char *string);
 extern char *utf8_add_offset (const char *string, int offset);
 extern int utf8_real_pos (const char *string, int pos);