feat: add string_last_position_of

lib/string.c

@@ -395,3 +395,15 @@ size_t string_position_of(const string_t string, const char character) {
   }
   return position_found;
 }
+
+size_t string_last_position_of(const string_t string, const char character) {
+  size_t position_found = 0;
+  size_t string_length = string_get_length(string);
+  while (string_length > 0 && position_found == 0) {
+    if (string[string_length - 1] == character) {
+      position_found = string_length;
+    }
+    string_length--;
+  }
+  return position_found;
+}

lib/string.h

@@ -270,9 +270,20 @@ bool string_ends_with(const string_t string, const string_t prefix);
  * @param string
  * @param substring
  * @return size_t
- * @example string_position_of("hello world", "e") // 2
+ * @example string_position_of("hello world", 'e') // 2
  * @since v4.2.0
  */
 size_t string_position_of(const string_t string, const char character);
 
+/**
+ * @brief Returns the position (index + 1) within the string of the last occurrence of the specified substring (0 if not found).
+ *
+ * @param string
+ * @param character
+ * @return size_t
+ * @example string_last_position_of("hello world", 'o') // 8
+ * @since v4.2.0
+ */
+size_t string_last_position_of(const string_t string, const char character);
+
 #endif

test/string_test.c

@@ -26,6 +26,7 @@ void string_test() {
   string_starts_with_test();
   string_ends_with_test();
   string_position_of_test();
+  string_last_position_of_test();
 }
 
 void string_get_length_test() {
@@ -281,6 +282,7 @@ void string_ends_with_test() {
 
 void string_position_of_test() {
   assert(string_position_of("hello world", 'e') == 2);
+  assert(string_position_of("hello world", 'o') == 5);
   assert(string_position_of("abcdef", 'a') == 1);
   assert(string_position_of("abcdef", 'b') == 2);
   assert(string_position_of("abcdef", 'c') == 3);
@@ -289,3 +291,15 @@ void string_position_of_test() {
   assert(string_position_of("abcdef", 'f') == 6);
   assert(string_position_of("abcdef", 'g') == 0);
 }
+
+void string_last_position_of_test() {
+  assert(string_last_position_of("hello world", 'e') == 2);
+  assert(string_last_position_of("hello world", 'o') == 8);
+  assert(string_last_position_of("abcdef", 'a') == 1);
+  assert(string_last_position_of("abcdef", 'b') == 2);
+  assert(string_last_position_of("abcdef", 'c') == 3);
+  assert(string_last_position_of("abcdef", 'd') == 4);
+  assert(string_last_position_of("abcdef", 'e') == 5);
+  assert(string_last_position_of("abcdef", 'f') == 6);
+  assert(string_last_position_of("abcdef", 'g') == 0);
+}

test/string_test.h

@@ -60,4 +60,6 @@ void string_ends_with_test();
 
 void string_position_of_test();
 
+void string_last_position_of_test();
+
 #endif