Implement LineClasses

src/comment.rs

@@ -901,6 +901,45 @@ where
     }
 }
 
+/// An iterator over the lines of a string, paired with the char kind at the
+/// end of the line.
+pub struct LineClasses<'a> {
+    base: iter::Peekable<CharClasses<std::str::Chars<'a>>>,
+    kind: FullCodeCharKind,
+}
+
+impl<'a> LineClasses<'a> {
+    pub fn new(s: &'a str) -> Self {
+        LineClasses {
+            base: CharClasses::new(s.chars()).peekable(),
+            kind: FullCodeCharKind::Normal,
+        }
+    }
+}
+
+impl<'a> Iterator for LineClasses<'a> {
+    type Item = (FullCodeCharKind, String);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.base.peek().is_none() {
+            return None;
+        }
+
+        let mut line = String::new();
+
+        while let Some((kind, c)) = self.base.next() {
+            self.kind = kind;
+            if c == '\n' {
+                break;
+            } else {
+                line.push(c);
+            }
+        }
+
+        Some((self.kind, line))
+    }
+}
+
 /// Iterator over functional and commented parts of a string. Any part of a string is either
 /// functional code, either *one* block comment, either *one* line comment. Whitespace between
 /// comments is functional code. Line comments contain their ending newlines.
@@ -1141,8 +1180,7 @@ fn remove_comment_header(comment: &str) -> &str {
 
 #[cfg(test)]
 mod test {
-    use super::{contains_comment, rewrite_comment, CharClasses, CodeCharKind, CommentCodeSlices,
-                FindUncommented, FullCodeCharKind};
+    use super::*;
     use shape::{Indent, Shape};
 
     #[test]
@@ -1298,4 +1336,10 @@ mod test {
         check("\"/* abc */\"", "abc", Some(4));
         check("\"/* abc", "abc", Some(4));
     }
+
+    #[test]
+    fn test_remove_trailing_white_spaces() {
+        let s = format!("    r#\"\n        test\n    \"#");
+        assert_eq!(remove_trailing_white_spaces(&s), s);
+    }
 }