Add more clippy warnings, and solve a bunch of them

src/document.rs

@@ -40,7 +40,7 @@ impl Document {
     }
 
     pub fn insert(&mut self, at: &Position, c: char) {
-        if at.y > self.len() {
+        if at.y > self.rows.len() {
             return;
         }
 
@@ -52,18 +52,20 @@ impl Document {
             return;
         }
 
-        if at.y == self.len() {
+        if at.y == self.rows.len() {
             let mut row = Row::default();
             row.insert(0, c);
             self.rows.push(row);
         } else {
-            let row = self.rows.get_mut(at.y).unwrap();
+            #[allow(clippy::indexing_slicing)]
+            let row = &mut self.rows[at.y];
             row.insert(at.x, c);
         }
     }
 
+    #[allow(clippy::integer_arithmetic, clippy::indexing_slicing)]
     pub fn delete(&mut self, at: &Position) {
-        let len = self.len();
+        let len = self.rows.len();
         if at.y >= len {
             return
         }
@@ -71,12 +73,12 @@ impl Document {
         // File has been modified
         self.dirty = true;
 
-        if at.x == self.rows.get_mut(at.y).unwrap().len() && at.y < len - 1 {
+        if at.x == self.rows[at.y].len() && at.y + 1 < len {
             let next_row = self.rows.remove(at.y + 1);
-            let row = self.rows.get_mut(at.y).unwrap();
+            let row = &mut self.rows[at.y];
             row.append(&next_row);
         } else {
-            let row = self.rows.get_mut(at.y).unwrap();
+            let row = &mut self.rows[at.y];
             row.delete(at.x);
         }
     }
@@ -102,12 +104,19 @@ impl Document {
     }
 
     fn insert_newline(&mut self, at: &Position) {
-        if at.y == self.len() {
+        if at.y > self.rows.len() {
+            return;
+        }
+
+        if at.y == self.rows.len() {
             self.rows.push(Row::default());
             return;
         }
 
-        let new_row = self.rows.get_mut(at.y).unwrap().split(at.x);
+        #[allow(clippy::indexing_slicing)]
+        let new_row = self.rows[at.y].split(at.x);
+
+        #[allow(clippy::integer_arithmetic)]
         self.rows.insert(at.y + 1, new_row);
     }
 }

src/editor.rs

@@ -64,11 +64,11 @@ impl Editor {
     pub fn default() -> Self {
         let args: Vec<String> = env::args().collect();
         let mut initial_status = String::from("HELP: Ctrl-S = save | Ctrl-Q = quit");
-        let document = if args.len() > 1 {
+        let document = if let Some(file_name) = args.get(1) {
             let file_name = &args[1];
             let doc = Document::open(&file_name);
-            if doc.is_ok() {
+            if let Ok(doc) = doc {
-                doc.unwrap()
+                doc
             } else {
                 initial_status = format!("ERR: Could not open file: {}", file_name);
                 Document::default()
@@ -134,9 +134,11 @@ impl Editor {
             self.cursor_position.y.saturating_add(1),
             self.document.len()
         );
+
+        #[allow(clippy::integer_arithmetic)]
         let len = status.len() + line_indicator.len();
         if width > len {
-            status.push_str(&" ".repeat(width - len));
+            status.push_str(&" ".repeat(width.saturating_sub(len)));
         }
         status = format!("{}{}", status, line_indicator);
         status.truncate(width);
@@ -235,11 +237,7 @@ impl Editor {
             self.refresh_screen()?;
 
             match Terminal::read_key()? {
-                Key::Backspace => {
+                Key::Backspace => result.truncate(result.len().saturating_sub(1)),
-                    if !result.is_empty() {
-                        result.truncate(result.len() - 1);
-                    }
-                }
                 Key::Char('\n') => break,
                 Key::Char(c) => {
                     if !c.is_control() {
@@ -322,14 +320,14 @@ impl Editor {
             },
             Key::PageUp => {
                 y  = if y > terminal_height {
-                    y - terminal_height
+                    y.saturating_sub(terminal_height)
                 } else {
                     0
                 }
             },
             Key::PageDown => {
                 y = if y.saturating_add(terminal_height) < height {
-                    y + terminal_height as usize
+                    y.saturating_add(terminal_height)
                 } else {
                     height
                 }
@@ -356,28 +354,36 @@ impl Editor {
         let mut welcome_message = format!("Hecto editor -- version {}", VERSION);
         let width = self.terminal.size().width as usize;
         let len = welcome_message.len();
+
+        #[allow(clippy::integer_arithmetic, clippy::integer_division)]
         let padding = width.saturating_sub(len) / 2;
         let spaces = " ".repeat(padding.saturating_sub(1));
+
         welcome_message = format!("~{}{}", spaces, welcome_message);
         welcome_message.truncate(width);
+
         println!("{}\r", welcome_message);
     }
 
     pub fn draw_row(&self, row: &Row) {
         let width = self.terminal.size().width as usize;
         let start = self.offset.x;
-        let end = self.offset.x + width;
+        let end = self.offset.x.saturating_add(width);
         let row = row.render(start, end);
         println!("{}\r", row);
     }
 
+    #[allow(clippy::integer_arithmetic, clippy::integer_division)]
     fn draw_rows(&self) {
         let height = self.terminal.size().height;
 
         for terminal_row in 0..height {
             Terminal::clear_current_line();
 
-            if let Some(row) = self.document.row(terminal_row as usize + self.offset.y) {
+            if let Some(row) = self
+                .document
+                .row(self.offset.y.saturating_add(terminal_row as usize))
+            {
                 self.draw_row(row);
             } else if self.document.is_empty() && terminal_row == height / 3 {
                 self.draw_welcome_message();

src/main.rs

@@ -1,4 +1,12 @@
-#![warn(clippy::all, clippy::pedantic)]
+#![warn(clippy::all, clippy::pedantic, clippy::restriction)]
+#![allow(
+    clippy::missing_docs_in_private_items,
+    clippy::implicit_return,
+    clippy::shadow_reuse,
+    clippy::print_stdout,
+    clippy::wildcard_enum_match_arm,
+    clippy::else_if_without_else
+)]
 mod document;
 mod editor;
 mod row;

src/row.rs

@@ -26,6 +26,7 @@ impl Row {
 
         let mut result = String::new();
 
+        #[allow(clippy::integer_arithmetic)]
         for grapheme in self.string[..]
             .graphemes(true)
             .skip(start)
@@ -69,6 +70,7 @@ impl Row {
         self.update_len();
     }
 
+    #[allow(clippy::integer_arithmetic)]
     pub fn delete(&mut self, at: usize) {
         if at >= self.len() {
             return