diff --git a/meli/src/mail/listing.rs b/meli/src/mail/listing.rs
index 9d559148..4730dbc4 100644
--- a/meli/src/mail/listing.rs
+++ b/meli/src/mail/listing.rs
@@ -113,9 +113,8 @@ impl<T> RowsState<T> {
             self.env_order.insert(env_hash, index);
             self.all_envelopes.insert(env_hash);
         }
-        if !self.all_threads.contains(&thread) {
+        if self.all_threads.insert(thread) {
             self.thread_order.insert(thread, index);
-            self.all_threads.insert(thread);
             self.thread_to_env.insert(thread, env_hashes);
         } else {
             self.thread_to_env
diff --git a/meli/src/terminal/embedded/terminal.rs b/meli/src/terminal/embedded/terminal.rs
index c6b56592..4a5b915a 100644
--- a/meli/src/terminal/embedded/terminal.rs
+++ b/meli/src/terminal/embedded/terminal.rs
@@ -930,11 +930,11 @@ impl EmbeddedGrid {
                     stdin
                         .write_all((terminal_size.1).to_string().as_bytes())
                         .unwrap();
-                    stdin.write_all(&[b';']).unwrap();
+                    stdin.write_all(b";").unwrap();
                     stdin
                         .write_all((terminal_size.0).to_string().as_bytes())
                         .unwrap();
-                    stdin.write_all(&[b't']).unwrap();
+                    stdin.write_all(b"t").unwrap();
                     stdin.flush().unwrap();
                 } else {
                     //log::trace!("ignoring unknown code {}",
@@ -947,15 +947,15 @@ impl EmbeddedGrid {
                 // Result is CSI r ; c R
                 //log::trace!("report cursor position");
                 //log::trace!("got {}", EscCode::from((&(*state), byte)));
-                stdin.write_all(&[b'\x1b', b'[']).unwrap();
+                stdin.write_all(b"\x1b[").unwrap();
                 stdin
                     .write_all((cursor.1 + 1).to_string().as_bytes())
                     .unwrap();
-                stdin.write_all(&[b';']).unwrap();
+                stdin.write_all(b";").unwrap();
                 stdin
                     .write_all((cursor.0 + 1).to_string().as_bytes())
                     .unwrap();
-                stdin.write_all(&[b'R']).unwrap();
+                stdin.write_all(b"R").unwrap();
                 stdin.flush().unwrap();
                 *state = State::Normal;
             }
diff --git a/meli/src/utilities.rs b/meli/src/utilities.rs
index b75b401c..f1a93615 100644
--- a/meli/src/utilities.rs
+++ b/meli/src/utilities.rs
@@ -299,8 +299,7 @@ impl Component for StatusBar {
                     crate::command::command_completion_suggestions(self.ex_buffer.as_str());
 
                 suggestions.extend(command_completion_suggestions.iter().filter_map(|e| {
-                    if !unique_suggestions.contains(e.as_str()) {
-                        unique_suggestions.insert(e.as_str());
+                    if unique_suggestions.insert(e.as_str()) {
                         Some(e.clone().into())
                     } else {
                         None
diff --git a/melib/src/imap/protocol_parser.rs b/melib/src/imap/protocol_parser.rs
index e52f50ae..9d06957c 100644
--- a/melib/src/imap/protocol_parser.rs
+++ b/melib/src/imap/protocol_parser.rs
@@ -1606,22 +1606,22 @@ fn atom_specials(input: &[u8]) -> IResult<&[u8], u8> {
 
 #[inline(always)]
 fn raw_chars(input: &[u8]) -> IResult<&[u8], u8> {
-    byte_in_slice(&[b'(', b')', b'{', b' '])(input)
+    byte_in_slice(b"(){ ")(input)
 }
 
 #[inline(always)]
 fn list_wildcards(input: &[u8]) -> IResult<&[u8], u8> {
-    byte_in_slice(&[b'%', b'*'])(input)
+    byte_in_slice(b"%*")(input)
 }
 
 #[inline(always)]
 fn quoted_specials(input: &[u8]) -> IResult<&[u8], u8> {
-    byte_in_slice(&[b'"', b'\\'])(input)
+    byte_in_slice(b"\"\\")(input)
 }
 
 #[inline(always)]
 fn resp_specials(input: &[u8]) -> IResult<&[u8], u8> {
-    byte_in_slice(&[b']'])(input)
+    byte_in_slice(b"]")(input)
 }
 
 #[inline(always)]
diff --git a/melib/src/mbox/write.rs b/melib/src/mbox/write.rs
index 454d8725..5084ddb6 100644
--- a/melib/src/mbox/write.rs
+++ b/melib/src/mbox/write.rs
@@ -179,7 +179,7 @@ impl MboxFormat {
                 writer.write_all(line_ending)?;
 
                 if body.starts_with(b"From ") {
-                    writer.write_all(&[b'>'])?;
+                    writer.write_all(b">")?;
                 }
                 let mut i = 0;
                 if crlf {
@@ -187,13 +187,13 @@ impl MboxFormat {
                         if body[i..].starts_with(CRLF) {
                             writer.write_all(CRLF)?;
                             if body[i..].starts_with(b"\r\nFrom ") {
-                                writer.write_all(&[b'>'])?;
+                                writer.write_all(b">")?;
                             }
                             i += 2;
                         } else if body[i] == b'\n' {
                             writer.write_all(CRLF)?;
                             if body[i..].starts_with(b"\nFrom ") {
-                                writer.write_all(&[b'>'])?;
+                                writer.write_all(b">")?;
                             }
                             i += 1;
                         } else {
@@ -206,13 +206,13 @@ impl MboxFormat {
                         if body[i..].starts_with(CRLF) {
                             writer.write_all(LF)?;
                             if body[i..].starts_with(b"\r\nFrom ") {
-                                writer.write_all(&[b'>'])?;
+                                writer.write_all(b">")?;
                             }
                             i += 2;
                         } else {
                             writer.write_all(&[body[i]])?;
                             if body[i..].starts_with(b"\nFrom ") {
-                                writer.write_all(&[b'>'])?;
+                                writer.write_all(b">")?;
                             }
                             i += 1;
                         }
diff --git a/melib/src/text/line_break.rs b/melib/src/text/line_break.rs
index 8ad1a3b8..8813e0c7 100644
--- a/melib/src/text/line_break.rs
+++ b/melib/src/text/line_break.rs
@@ -1624,10 +1624,7 @@ impl Iterator for LineBreakText {
                         *state = LineBreakTextState::AtLine {
                             cur_index: *cur_index + line.len() + 1,
                         };
-                        return Some(
-                            line.trim_end_matches(|c| c == '\r' || c == '\n')
-                                .to_string(),
-                        );
+                        return Some(line.trim_end_matches(['\r', '\n']).to_string());
                     }
                     if breaks.len() < 2 {
                         let mut line = line;
@@ -1673,14 +1670,14 @@ impl Iterator for LineBreakText {
                         if !line[*within_line_index..end_offset].is_empty() {
                             if *within_line_index == 0 {
                                 let ret = line[*within_line_index..end_offset]
-                                    .trim_end_matches(|c| c == '\r' || c == '\n');
+                                    .trim_end_matches(['\r', '\n']);
                                 *within_line_index = end_offset;
                                 return Some(ret.to_string());
                             } else {
                                 let ret = format!(
                                     "⤷{}",
                                     &line[*within_line_index..end_offset]
-                                        .trim_end_matches(|c| c == '\r' || c == '\n')
+                                        .trim_end_matches(['\r', '\n'])
                                 );
                                 *within_line_index = end_offset;
                                 return Some(ret);