Simplified comment matching regex

src/regexes.rs

@@ -7,8 +7,7 @@ lazy_static! {
     pub static ref RE_NEWLINES: Regex = Regex::new(r"\n\n\n+").unwrap();
     pub static ref RE_TABS: Regex = Regex::new(r"\t").unwrap();
     pub static ref RE_TRAIL: Regex = Regex::new(r" +\n").unwrap();
-    pub static ref RE_PERCENT: Regex = Regex::new(r"\\\%").unwrap();
-    pub static ref RE_COMMENT: Regex = Regex::new(r"\%.*").unwrap();
+    pub static ref RE_COMMENT: Regex = Regex::new(r"(?P<text>.*^|[^\\])(?P<comm>\%.*$)").unwrap();
     pub static ref RE_ITEM: Regex = Regex::new(r".*\\item.*").unwrap();
     pub static ref RE_DOCUMENT_BEGIN: Regex =
         Regex::new(r".*\\begin\{document\}.*").unwrap();

src/subs.rs

@@ -42,6 +42,5 @@ pub fn remove_trailing_spaces(file: &str) -> String {
 //}
 
 pub fn remove_comment(line: &str) -> String {
-    let new_line = RE_PERCENT.replace_all(line, "").to_string();
-    RE_COMMENT.replace_all(&new_line, "").to_string()
+    RE_COMMENT.replace_all(line, "$text").to_string()
 }

tests/comments_in.tex

@@ -15,4 +15,8 @@
 % Similarly they might contain \begin{align}
 % unmatched environment tags.
 
+This is a percent sign \% and not a comment
+
+Some lines might have both \% percents % and comments \end{align}
+
 \end{document}

tests/comments_out.tex

@@ -15,4 +15,8 @@
 % Similarly they might contain \begin{align}
 % unmatched environment tags.
 
+This is a percent sign \% and not a comment
+
+Some lines might have both \% percents % and comments \end{align}
+
 \end{document}