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use crate::String;
impl<const N: usize> core::ops::Deref for String<N> {
type Target = str;
fn deref(&self) -> &Self::Target {
self.as_str()
}
}
impl<const N: usize> String<N> {
/// Creates a new string, with maximum byte length `N`.
///
/// Note that this doesn't create a string with a maximum length of `N` characters, but rather of `N` bytes. (UTF-8 characters can be multiple bytes long.)
pub fn new() -> Self {
String { chars: [0; N], len: 0 }
}
/// [`std::string::String::as_mut_str()`](https://doc.rust-lang.org/std/string/struct.String.html#method.as_mut_str)
pub fn as_mut_str(&mut self) -> &mut str {
// Convert the byte slice to a string slice
core::str::from_utf8_mut(&mut self.chars[..self.len]).unwrap()
}
/// [`std::string::String::as_str()`](https://doc.rust-lang.org/std/string/struct.String.html#method.as_str)
pub fn as_str(&self) -> &str {
// Convert the byte slice to a string slice
core::str::from_utf8(&self.chars[..self.len]).unwrap()
}
/// [`std::string::String::capacity()`](https://doc.rust-lang.org/std/string/struct.String.html#method.capacity)
pub fn capacity(&self) -> usize {
N
}
/// [`std::string::String::chars()`](https://doc.rust-lang.org/std/string/struct.String.html#method.chars)
pub fn chars(&self) -> core::str::Chars {
self.as_str().chars()
}
/// [`std::string::String::clear()`](https://doc.rust-lang.org/std/string/struct.String.html#method.clear)
pub fn clear(&mut self) {
self.len = 0;
}
/// [`std::string::String::drain()`](https://doc.rust-lang.org/std/string/struct.String.html#method.drain)
/// Note that this implementation is not the same as the one in the standard library. It does the same, but rather returns the removed chars as a new string. This is because the Drain iterator is not in the `core` library.
pub fn drain(&mut self, range: core::ops::Range<usize>) -> String<N> {
// remove the chars in range
// return the removed chars
let mut i = range.start;
let mut j = range.end;
let mut s = String::<N>::new();
while i < j {
s.push(self.chars[i] as char);
i+=1;
}
while j < self.len {
self.chars[j-(range.end-range.start)] = self.chars[j];
j+=1;
}
self.len -= range.end-range.start;
s
}
/// [`std::string::String::extend_from_within()`](https://doc.rust-lang.org/std/string/struct.String.html#method.extend_from_within)
pub fn extend_from_within(&mut self, range: core::ops::Range<usize>) {
// extend the string with the chars in range
let mut i = range.start;
while i < range.end {
self.push(self.chars[i] as char);
i+=1;
}
}
/// [`std::string::String::from()`](https://doc.rust-lang.org/std/string/struct.String.html#method.from)
pub fn from(s: &str) -> Self {
let mut str = String::<N>::new();
str.push_str(s);
str
}
/// [`std::string::String::get()`](https://doc.rust-lang.org/std/string/struct.String.html#method.get)
pub fn get<I>(&self, index: I) -> Option<&str>
where
I: core::slice::SliceIndex<[u8], Output = [u8]>,
{
self.chars.get(index).map(|slice| core::str::from_utf8(slice)).transpose().unwrap()
}
/// [`std::string::String::get_mut()`](https://doc.rust-lang.org/std/string/struct.String.html#method.get_mut)
pub fn get_mut<I>(&mut self, index: I) -> Option<&mut str>
where
I: core::slice::SliceIndex<[u8], Output = [u8]>,
{
self.chars.get_mut(index).map(|slice| core::str::from_utf8_mut(slice)).transpose().unwrap()
}
/// [`std::string::String::get_unchecked()`](https://doc.rust-lang.org/std/string/struct.String.html#method.get_unchecked)
pub fn get_unchecked<I>(&self, index: I) -> &str
where
I: core::slice::SliceIndex<[u8], Output = [u8]>,
{
core::str::from_utf8(self.chars.get(index).unwrap()).unwrap()
}
/// [`std::string::String::get_unchecked_mut()`](https://doc.rust-lang.org/std/string/struct.String.html#method.get_unchecked_mut)
pub fn get_unchecked_mut<I>(&mut self, index: I) -> &mut str
where
I: core::slice::SliceIndex<[u8], Output = [u8]>,
{
core::str::from_utf8_mut(self.chars.get_mut(index).unwrap()).unwrap()
}
/// [`std::string::String::insert()`](https://doc.rust-lang.org/std/string/struct.String.html#method.insert)
pub fn insert(&mut self, index: usize, c: char) {
// iterate while index < self.len
// push each char to the array
let mut i = index;
let mut prev = c;
while i < self.len {
let tmp = self.chars[i] as char;
self.chars[i] = prev as u8;
prev = tmp;
i+=1;
}
self.chars[i] = prev as u8;
self.len += 1;
}
/// [`std::string::String::insert_str()`](https://doc.rust-lang.org/std/string/struct.String.html#method.insert_str)
pub fn insert_str(&mut self, index: usize, s: &str) {
// iterate while index < s.len
// push each char to the array
let mut i = index;
for c in s.chars() {
self.insert(i, c);
i+=1;
}
}
/// [`std::string::String::lines()`](https://doc.rust-lang.org/std/string/struct.String.html#method.lines)
pub fn lines(&self) -> core::str::Lines {
self.as_str().lines()
}
/// [`std::string::String::make_ascii_lowercase()`](https://doc.rust-lang.org/std/string/struct.String.html#method.make_ascii_lowercase)
pub fn make_ascii_lowercase(&mut self) {
// convert the string to ascii
for c in self.clone().as_str().chars() {
self.push(c.to_ascii_lowercase());
}
}
/// [`std::string::String::make_ascii_uppercase()`](https://doc.rust-lang.org/std/string/struct.String.html#method.make_ascii_uppercase)
pub fn make_ascii_uppercase(&mut self) {
// convert the string to ascii
for c in self.clone().as_str().chars() {
self.push(c.to_ascii_uppercase());
}
}
/// [`std::string::String::pop()`](https://doc.rust-lang.org/std/string/struct.String.html#method.pop)
pub fn pop(&mut self) -> Option<char> {
// remove the last char
// return the char
if self.len > 0 {
let c = self.chars[self.len-1] as char;
self.len -= 1;
Some(c)
} else {
None
}
}
/// [`std::string::String::push()`](https://doc.rust-lang.org/std/string/struct.String.html#method.push)
pub fn push(&mut self, c: char) {
// Convert the char to a byte sequence
let dst = &mut [0; 4];
let bytes = c.encode_utf8(dst).as_bytes();
// Iterate over the bytes and push them to the array
for &byte in bytes {
// Check if there is enough space in the array
if self.len < N {
// Add the byte to the array
self.chars[self.len] = byte;
// Increment the length
self.len += 1;
} else {
panic!("String is full")
}
}
}
/// [`std::string::String::push_str()`](https://doc.rust-lang.org/std/string/struct.String.html#method.push_str)
pub fn push_str(&mut self, s: &str) {
// Iterate over the chars of the string
for c in s.chars() {
// Push each char to the array
self.push(c);
}
}
/// [`std::string::String::remove()`](https://doc.rust-lang.org/std/string/struct.String.html#method.remove)
pub fn remove(&mut self, index: usize) -> char {
// remove the char at index
// return the char
let mut i = index;
let mut c = ' ';
while i < self.len {
c = self.chars[i] as char;
self.chars[i] = self.chars[i+1];
i+=1;
}
self.len -= 1;
c
}
/// [`std::string::String::repeat()`](https://doc.rust-lang.org/std/string/struct.String.html#method.repeat)
pub fn repeat(&self, n: usize) -> String<N> {
// repeat the string n times
let mut s = String::<N>::new();
for _ in 0..n {
s.push_str(self.as_str());
}
s
}
/// [`std::string::String::replace()`](https://doc.rust-lang.org/std/string/struct.String.html#method.replace)
pub fn replace(&self, from: &str, to: &str) -> String<N> {
// iterate over the chars of self
// check if the chars of self are equal to from
// if yes, push to to the string
let mut i = 0;
let mut j = 0;
let mut s = String::<N>::new();
while i < self.len {
if self.chars[i] == from.as_bytes()[j] {
j+=1;
if j == from.len() {
s.push_str(to);
j = 0;
}
} else {
j = 0;
}
s.push(self.chars[i] as char);
i+=1;
}
s
}
/// [`std::string::String::replacen()`](https://doc.rust-lang.org/std/string/struct.String.html#method.replacen)
pub fn replacen(&self, from: &str, to: &str, n: usize) -> String<N> {
// iterate over the chars of self
// check if the chars of self are equal to from
// if yes, push to to the string
let mut i = 0;
let mut j = 0;
let mut s = String::<N>::new();
let mut count = 0;
while i < self.len {
if self.chars[i] == from.as_bytes()[j] {
j+=1;
if j == from.len() {
s.push_str(to);
j = 0;
count+=1;
if count == n {
break;
}
}
} else {
j = 0;
}
s.push(self.chars[i] as char);
i+=1;
}
s
}
/// [`std::string::String::retain()`](https://doc.rust-lang.org/std/string/struct.String.html#method.retain)
pub fn retain<F>(&mut self, mut f: F)
where
F: FnMut(char) -> bool,
{
// iterate over the chars of self
// check if the char should be removed
let mut i = 0;
while i < self.len {
if !f(self.chars[i] as char) {
self.remove(i);
} else {
i+=1;
}
}
}
/// [`std::string::String::rfind()`](https://doc.rust-lang.org/std/string/struct.String.html#method.rfind)
pub fn rfind(&self, s: &str) -> Option<usize> {
// iterate over the chars of self
// check if the chars of self are equal to s
let mut i = self.len - 1;
let mut j = s.len() - 1;
while i > 0 {
if self.chars[i] == s.as_bytes()[j] {
j-=1;
if j == 0 {
return Some(i-j+1);
}
} else {
j = s.len() - 1;
}
i-=1;
}
None
}
/// [`std::string::String::starts_with()`](https://doc.rust-lang.org/std/string/struct.String.html#method.starts_with)
pub fn starts_with(&self, s: &str) -> bool {
// iterate over the chars of s
// check if the first chars of self are equal to s
let mut i = 0;
let mut j = 0;
while i < s.len() {
if self.chars[j] != s.as_bytes()[i] {
return false;
}
i+=1;
j+=1;
}
true
}
/// [`std::string::String::to_ascii_lowercase()`](https://doc.rust-lang.org/std/string/struct.String.html#method.to_ascii_lowercase)
pub fn to_ascii_lowercase(&self) -> String<N> {
// convert the string to lowercase
let mut s = String::<N>::new();
for c in self.as_str().chars() {
s.push(c.to_ascii_lowercase());
}
s
}
/// [`std::string::String::to_ascii_uppercase()`](https://doc.rust-lang.org/std/string/struct.String.html#method.to_ascii_uppercase)
pub fn to_ascii_uppercase(&self) -> String<N> {
// convert the string to uppercase
let mut s = String::<N>::new();
for c in self.as_str().chars() {
s.push(c.to_ascii_uppercase());
}
s
}
/// [`std::string::String::to_lowercase()`](https://doc.rust-lang.org/std/string/struct.String.html#method.to_lowercase)
pub fn to_lowercase(&self) -> String<N> {
// convert the string to lowercase
let mut s = String::<N>::new();
for c in self.as_str().chars() {
s.push(c.to_lowercase().next().unwrap());
}
s
}
/// [`std::string::String::to_uppercase()`](https://doc.rust-lang.org/std/string/struct.String.html#to_uppercase.to_mut)
pub fn to_uppercase(&self) -> String<N> {
// convert the string to uppercase
let mut s = String::<N>::new();
for c in self.as_str().chars() {
s.push(c.to_uppercase().next().unwrap());
}
s
}
/// [`std::string::String::truncate()`](https://doc.rust-lang.org/std/string/struct.String.html#method.truncate)
pub fn truncate(&mut self, new_len: usize) {
// truncate the string to new_len
// if new_len < self.len
if new_len < self.len {
self.len = new_len;
}
}
}