more exts

src/ext.rs

@@ -17,6 +17,52 @@ use tokio::{
 };
 use futures::future::Future;
 
+#[derive(Debug)]
+pub struct GroupIter<I, T>(std::iter::Fuse<I>, Vec<T>, usize);
+
+impl<I: Iterator<Item=T>, T> Iterator for GroupIter<I, T>
+{
+    type Item = Box<[T]>;
+    fn next(&mut self) -> Option<Self::Item>
+    {
+	if self.1.len() == 0 {
+	    // fill
+	    for (_, item) in (0..self.2).zip(&mut self.0)
+	    {
+		self.1.push(item);
+	    }
+	}
+	if self.1.len() == 0 {
+	    None
+	} else{
+	    Some(std::mem::replace(&mut self.1, Vec::with_capacity(self.2)).into())
+	}
+    }
+    
+    fn size_hint(&self) -> (usize, Option<usize>) {
+	let (low, high) = self.0.size_hint();
+	(low / self.2, high.map(|x| (x / self.2) + 1)) //not too sure if this is right...
+    }
+}
+impl<I: Iterator<Item=T>, T> std::iter::FusedIterator for GroupIter<I, T>{}
+
+pub trait GroupIterExt<I, T>: Sized
+{
+    /// Group this iterator to return a boxed slice of every `n` items.
+    ///
+    /// # Notes
+    /// If there isn't `n` items left in the iterator, then the rest is returned.
+    fn group(self, n: usize) -> GroupIter<I, T>;
+}
+
+impl<T: IntoIterator> GroupIterExt<<T as IntoIterator>::IntoIter, <T as IntoIterator>::Item> for T
+{
+    fn group(self, every: usize) -> GroupIter<<T as IntoIterator>::IntoIter, <T as IntoIterator>::Item>
+    {
+	GroupIter(self.into_iter().fuse(), Vec::with_capacity(every), every)
+    }
+}
+
 pub trait JoinStrsExt: Sized
 {
     /// Join an iterator of `str` with a seperator
@@ -24,14 +70,15 @@ pub trait JoinStrsExt: Sized
 }
 
 impl<T,I> JoinStrsExt for I
-where I: Iterator<Item=T>,
+where I: IntoIterator<Item=T>,
       T: AsRef<str>
 {
+    /// Join an iterator of `str` with a seperator
     fn join(self, with: &str) -> String
     {
 	let mut output = String::new();
 	let mut first=true;
-	for string in self
+	for string in self.into_iter()
 	{
 	    if !first {
 		output.push_str(with);
@@ -44,60 +91,99 @@ where I: Iterator<Item=T>,
     }
 }
 
-/*macro_rules! typed_swap {
-(@ [] $($reversed:tt)*) => { 
-fn swap(self) -> ($($reversed)*);
-    };
-    (@ [$first:tt $($rest:tt)*] $($reversed:tt)*) => { 
-        typed_swap!{@ [$($rest)*] $first $($reversed)*}
-    };
-    (@impl {$($body:tt)*} [] $($reversed:tt)*) => { 
-        fn swap(self) -> ($($reversed)*)
+#[derive(Debug, Clone)]
+pub struct StrChunks<'a, T: ?Sized>(&'a str, usize, PhantomData<&'a T>);
+
+impl<'a, T: ?Sized>  StrChunks<'a, T>
 {
-	    $($body)*
+    /// The rest of the string
+    pub fn as_str(&self) -> &'a str
+    {
+	&self.0[..]
     }
-    };
-    (@impl {$($body:tt)*} [$first:tt $($rest:tt)*] $($reversed:tt)*) => { 
-        typed_swap!{@impl {$($body)*} [$($rest)*] $first $($reversed)*}
-    };
-    () => {};
-    ({$($params:tt)*} $($rest:tt)*) => {
-	mod swap {
-	    pub trait SwapTupleExt<$($params)*>: Sized
+    /// The number of chars to break at
+    pub fn every(&self) -> usize
     {
-		typed_swap!(@ [$($params)*]);
+	self.1
     }
+    /// Set the number of chars to break at.
+    ///
+    /// # Note
+    /// Probably don't do this unless you know what you're doing.
+    pub fn every_mut(&mut self) -> &mut usize
+    {
+	&mut self.1
+    }
+}
+impl<'a, T: ?Sized> Iterator for StrChunks<'a, T>
+{
+    type Item = &'a str;
+    fn next(&mut self) -> Option<Self::Item>
+    {
+	match self.0.char_indices().nth(self.1).map(|x| x.0) {
+	    None if self.0.len() > 0 => Some(std::mem::replace(&mut self.0, "")),
+	    Some(i) => {
+		let (left, right) = self.0.split_at(i);
+		self.0 = right;
+		Some(left) 
+	    },
+	    _ => None,
+	}
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+	let (low, high) = self.0.chars().size_hint();
+	(low / self.1, high.map(|x| (x / self.1) + 1)) //not too sure if this is right...
+    }
+}
+impl<'a, T: ?Sized> std::iter::FusedIterator for StrChunks<'a, T>{}
 
-	    impl<$($params)*> SwapTupleExt<$($params)*> for ($($params)*)
+/// Split a `str` into chunks on char boundaries
+pub trait ChunkStrsExt
 {
-		typed_swap!(@impl {
-		    todo!()
-		} [$($params)*]);
+    /// Split this str into a chunking iterator every specified number of chars.
+    ///
+    /// If there are not enough chars left in the string, the rest is returned.
+    /// # Note
+    /// This operates on codepoints, not bytes.
+    fn chunk(&self, every: usize) -> StrChunks<'_, Self>;
 }
 
-	    typed_swap!($($rest)*);
+#[cfg(test)]
+mod chunk_tests
+{
+    use super::*;
+    #[test]
+    fn chunk_test()
+    {
+	let string = r"a2eab409c57a829d23139c61ff2d5e479260c96158ebec0ce4d458afb85b76dłこんな僕は生きてるだけ何万人の人が悲しいんで。!?";
+	assert_eq!(&string.chunk(8).join("")[..], string);
+	for chunk in string.chunk(8) {
+	    println!("{}", chunk);
 	}
-	pub use swap::*;
-    };
+    }
+
+    #[test]
+    fn group_test()
+    {
 
-    (all $first:tt $($params:tt)+) => {
-	typed_swap!({$first, $($params),+});
-	mod nswap {
-	    typed_swap!(all $($params)+);
+	let string = r"a2eab409c57a829d23139c61ff2d5e479260c96158ebec0ce4d458afb85b76dłこんな僕は生きてるだけ何万人の人が悲しいんで。!?";
+	let astr: String = string.chars().group(8).map(|x| -> String {x.iter().collect()}).collect();
+	assert_eq!(&astr[..], string);
+	for chunk in string.chars().group(8) {
+	    println!("{:?}", chunk);
+	}
     }
-    };
-    (all $($one:tt)?) => {};
 }
 
-typed_swap!(all A B C D E F G H I J K L M N O P Q R S T U V W X Y Z);
-pub use swap::*;
 
-fn test()
+impl<T: AsRef<str>+?Sized> ChunkStrsExt for T
 {
-    let sw = (1, 2).swap();
-    
-}*/
-// ^ unfortunately not lol
+    fn chunk(&self, every: usize) -> StrChunks<'_, Self>
+    {
+	StrChunks(self.as_ref(), every, PhantomData)
+    }
+}
 
 pub trait SwapTupleExt<T,U>: Sized
 {
@@ -110,11 +196,6 @@ impl<T,U> SwapTupleExt<T,U> for (T,U)
     }
 }
 
-/*typed_swap!({A, B}
-	    {A, U, V}
-	    {T, U, V, W});*/
-
-
 const ASCII_MAP: [char; 256] = [
     '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', 
     '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.', 

src/main.rs

@@ -163,7 +163,7 @@ async fn fuck() -> eyre::Result<()>
     println!("Wrote {} bytes", written);
     println!("{}\n", ser.fmt_view());
 
-    println!("As text:\n{}\n", String::from_utf8_lossy(&ser[..]));
+    println!("As text:\n{}\n", ser.fmt_ascii());
 
     let mut read = &ser[..];
     let (reads, readn) = SuperHeader::from_memory(&mut read, serialise::Mode::Binary, |salt| Some(Password::derive(password, salt)))?; // SuperHeader::read_text(read).await?;