Add line command

src/buffer.rs

@@ -33,7 +33,7 @@ use crate::{Cursor, Direction};
 #[derive(Clone, Debug)]
 pub struct Buffer {
     styles: Arc<Mutex<StyleStore>>,
-    pub text: Rope,
+    text: Rope,
     syntax_set: Arc<SyntaxSet>,
     parser: ParseState,
     style_dirty: bool,
@@ -41,6 +41,12 @@ pub struct Buffer {
     styled: Vec<Vec<(Style, Range<usize>)>>,
 }
 
+impl AsRef<Rope> for Buffer {
+    fn as_ref(&self) -> &Rope {
+        &self.text
+    }
+}
+
 impl Buffer {
     pub fn from_str(styles: Arc<Mutex<StyleStore>>, text: &str) -> Self {
         let syntax_set = SyntaxSet::load_defaults_nonewlines();

src/main.rs

@@ -325,7 +325,7 @@ impl State {
     }
 
     fn write_buffer(&mut self, file: OsString) -> Result<()> {
-        let out = self.buffer.text.bytes().collect::<Vec<u8>>();
+        let out = self.buffer.as_ref().bytes().collect::<Vec<u8>>();
         let mut handle = OpenOptions::new().write(true).open(file)?;
 
         handle.write_all(out.as_slice())?;
@@ -364,9 +364,16 @@ impl State {
                 self.write_command(command, args)?;
                 self.quit = true;
             }
-            command => {
-                return Err(format!("{}: Unrecognized command.", command));
-            }
+            command => match command.parse::<usize>() {
+                Err(_) => return Err(format!("{}: Unrecognized command.", command)),
+                Ok(line) if line >= self.buffer.as_ref().len_lines() => {
+                    return Err(format!("Line {} is out-of-bounds", line))
+                }
+                Ok(line) => {
+                    self.cursor.line = line;
+                    self.scroll_to_cursor();
+                }
+            },
         }
 
         Ok(())
@@ -374,7 +381,10 @@ impl State {
 
     fn move_cursor(&mut self, direction: Direction) {
         self.buffer.move_cursor(&mut self.cursor, direction, true);
+        self.scroll_to_cursor();
+    }
 
+    fn scroll_to_cursor(&mut self) {
         if self.cursor.column < self.scroll.column + 3 {
             self.scroll.column = self.cursor.column.saturating_sub(3);
         } else if self.cursor.column + 6 >= self.scroll.column + self.size.0 {