1#![warn(missing_docs)]
2//!
3//! Normalize line endings
4//!
5//! This crate provides a `normalize` method that takes a char iterator and returns
6//! a new one with `\n` for all line endings
7
8/// This struct wraps a `std::io::Chars` to normalize line endings.
9///
10/// Implements `Iterator<Item=char>` so can be used in place
11struct Normalized<I> {
12 iter: I,
13 prev_was_cr: bool,
14}
15
16/// Take a Chars and return similar struct with normalized line endings
17///
18/// # Example
19/// ```
20/// use std::iter::FromIterator;
21/// use normalize_line_endings::normalized;
22///
23/// let input = "This is a string \n with \r some \n\r\n random newlines\r\r\n\n";
24/// assert_eq!(
25/// &String::from_iter(normalized(input.chars())),
26/// "This is a string \n with \n some \n\n random newlines\n\n\n"
27/// );
28/// ```
29#[inline]
30pub fn normalized(iter: impl Iterator<Item = char>) -> impl Iterator<Item = char> {
31 Normalized {
32 iter,
33 prev_was_cr: false,
34 }
35}
36
37impl<I> Iterator for Normalized<I>
38where
39 I: Iterator<Item = char>,
40{
41 type Item = char;
42 fn next(&mut self) -> Option<char> {
43 match self.iter.next() {
44 Some('\n') if self.prev_was_cr => {
45 self.prev_was_cr = false;
46 match self.iter.next() {
47 Some('\r') => {
48 self.prev_was_cr = true;
49 Some('\n')
50 }
51 any => {
52 self.prev_was_cr = false;
53 any
54 }
55 }
56 }
57 Some('\r') => {
58 self.prev_was_cr = true;
59 Some('\n')
60 }
61 any => {
62 self.prev_was_cr = false;
63 any
64 }
65 }
66 }
67}
68
69// tests
70#[cfg(test)]
71mod tests {
72 use std::iter::FromIterator;
73
74 #[test]
75 fn normalized() {
76 let input = "This is a string \n with \r some \n\r\n random newlines\r\r\n\n";
77 assert_eq!(
78 &String::from_iter(super::normalized(input.chars())),
79 "This is a string \n with \n some \n\n random newlines\n\n\n"
80 );
81 }
82}
83