object: add a range of string transformation functions

object/string.c

@@ -199,6 +199,45 @@ b_status b_string_reserve(struct b_string *str, size_t capacity)
 	return err == 0 ? B_SUCCESS : B_ERR_NO_MEMORY;
 }
 
+b_status b_string_replace(
+	struct b_string *str, size_t start, size_t length, const char *new_data)
+{
+	b_status status = B_SUCCESS;
+	size_t new_data_len = strlen(new_data);
+
+	if (start >= str->s_len) {
+		return B_ERR_INVALID_ARGUMENT;
+	}
+
+	if (start + length >= str->s_len) {
+		length = str->s_len - start;
+	}
+
+	size_t new_str_len = str->s_len - length + new_data_len;
+	if (new_str_len > str->s_max) {
+		status = b_string_reserve(str, new_str_len);
+	}
+
+	if (!B_OK(status)) {
+		return status;
+	}
+
+	char *s = string_ptr(str);
+
+	char *substitution_start = s + start;
+	char *excess_src = s + start + length;
+	size_t excess_length = str->s_len - start - length;
+	char *excess_dest = substitution_start + new_data_len;
+
+	memmove(excess_dest, excess_src, excess_length);
+	memmove(substitution_start, new_data, new_data_len);
+	s[new_str_len] = '\0';
+
+	str->s_len = new_str_len;
+
+	return B_SUCCESS;
+}
+
 b_status b_string_replace_all(b_string *str, const char *new_data)
 {
 	size_t new_len = strlen(new_data);
@@ -211,6 +250,48 @@ b_status b_string_replace_all(b_string *str, const char *new_data)
 	return B_SUCCESS;
 }
 
+b_status b_string_remove(b_string *str, size_t start, size_t length)
+{
+	b_status status = B_SUCCESS;
+
+	if (start >= str->s_len) {
+		return B_ERR_INVALID_ARGUMENT;
+	}
+
+	if (start + length >= str->s_len) {
+		length = str->s_len - start;
+	}
+
+	size_t new_str_len = str->s_len - length;
+
+	char *s = string_ptr(str);
+
+	char *removal_start = s + start;
+	char *excess_src = s + start + length;
+	size_t excess_length = str->s_len - start - length;
+
+	memmove(removal_start, excess_src, excess_length);
+	s[new_str_len] = '\0';
+
+	str->s_len = new_str_len;
+
+	return B_SUCCESS;
+}
+
+b_status b_string_transform(b_string *str, int (*transformer)(int))
+{
+	char *s = string_ptr(str);
+	for (size_t i = 0; i < str->s_len; i++) {
+		int c = transformer(s[i]);
+
+		if (c != 0) {
+			s[i] = c;
+		}
+	}
+
+	return B_SUCCESS;
+}
+
 static enum b_status stream_close(struct b_stream *stream)
 {
 	struct b_string *str = stream->s_ptr;