feat: add string_position_of

lib/string.c

@@ -384,3 +384,14 @@ bool string_ends_with(const string_t string, const string_t prefix) {
   }
   return ends_with;
 }
+
+size_t string_position_of(const string_t string, const char character) {
+  size_t position_found = 0;
+  size_t string_length = string_get_length(string);
+  for (size_t index = 0; index < string_length && position_found == 0; index++) {
+    if (string[index] == character) {
+      position_found = index + 1;
+    }
+  }
+  return position_found;
+}

lib/string.h

@@ -264,4 +264,15 @@ bool string_starts_with(const string_t string, const string_t prefix);
  */
 bool string_ends_with(const string_t string, const string_t prefix);
 
+/**
+ * @brief Returns the position (index + 1) within the string of the first occurrence of the specified substring (0 if not found).
+ *
+ * @param string
+ * @param substring
+ * @return size_t
+ * @example string_position_of("hello world", "e") // 2
+ * @since v4.2.0
+ */
+size_t string_position_of(const string_t string, const char character);
+
 #endif

test/string_test.c

@@ -25,6 +25,7 @@ void string_test() {
   string_get_last_occurence_of_character_test();
   string_starts_with_test();
   string_ends_with_test();
+  string_position_of_test();
 }
 
 void string_get_length_test() {
@@ -277,3 +278,14 @@ void string_ends_with_test() {
   assert(!string_ends_with("abcdef", "bcd"));
   assert(!string_ends_with("abcdef", "abcdefg"));
 }
+
+void string_position_of_test() {
+  assert(string_position_of("hello world", 'e') == 2);
+  assert(string_position_of("abcdef", 'a') == 1);
+  assert(string_position_of("abcdef", 'b') == 2);
+  assert(string_position_of("abcdef", 'c') == 3);
+  assert(string_position_of("abcdef", 'd') == 4);
+  assert(string_position_of("abcdef", 'e') == 5);
+  assert(string_position_of("abcdef", 'f') == 6);
+  assert(string_position_of("abcdef", 'g') == 0);
+}

test/string_test.h

@@ -58,4 +58,6 @@ void string_starts_with_test();
 
 void string_ends_with_test();
 
+void string_position_of_test();
+
 #endif