object: add a range of string transformation functions

object-test/strings.c

@@ -5,10 +5,26 @@
 
 int main(void)
 {
+	printf("-------------\n");
 	b_string *str = b_string_create_from_cstr("Hello, world!\n");
+	printf("%s\n", b_string_ptr(str));
+	printf("len:%zu, max:%zu\n", b_string_get_size(str, B_STRLEN_NORMAL),
+	       b_string_get_capacity(str));
+
 	b_string_insert_cstr(str, "WOW!", 4);
 
+	printf("-------------\n");
 	printf("%s\n", b_string_ptr(str));
+	printf("len:%zu, max:%zu\n", b_string_get_size(str, B_STRLEN_NORMAL),
+	       b_string_get_capacity(str));
+
+	b_string_replace(str, 4, 4, "+");
+
+	printf("-------------\n");
+	printf("%s\n", b_string_ptr(str));
+	printf("len:%zu, max:%zu\n", b_string_get_size(str, B_STRLEN_NORMAL),
+	       b_string_get_capacity(str));
+	printf("-------------\n");
 
 	b_string_release(str);
 

object/include/blue/object/string.h

@@ -4,6 +4,7 @@
 #include <blue/core/status.h>
 #include <blue/object/object.h>
 #include <blue/object/type.h>
+#include <ctype.h>
 
 struct b_stream;
 
@@ -34,7 +35,19 @@ static inline void b_string_release(b_string *str)
 }
 BLUE_API char *b_string_steal(b_string *str);
 BLUE_API b_status b_string_reserve(b_string *str, size_t capacity);
+BLUE_API b_status b_string_replace(
+	b_string *str, size_t start, size_t length, const char *new_data);
 BLUE_API b_status b_string_replace_all(b_string *str, const char *new_data);
+BLUE_API b_status b_string_remove(b_string *str, size_t start, size_t length);
+BLUE_API b_status b_string_transform(b_string *str, int (*transformer)(int));
+static inline b_status b_string_toupper(b_string *str)
+{
+	return b_string_transform(str, toupper);
+}
+static inline b_status b_string_tolower(b_string *str)
+{
+	return b_string_transform(str, tolower);
+}
 BLUE_API b_status b_string_open_stream(b_string *str, struct b_stream **out);
 
 BLUE_API void b_string_append_s(b_string *dest, const b_string *src);

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;