From afaf3ab0fefe718468cbd7b4ac88ae8ee75ee948 Mon Sep 17 00:00:00 2001
From: mars <mars@tebibyte.media>
Date: Wed, 12 Apr 2023 17:39:46 -0400
Subject: [PATCH 1/6] Add line command

---
 src/buffer.rs |  8 +++++++-
 src/main.rs   | 18 ++++++++++++++----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/buffer.rs b/src/buffer.rs
index 73975d5..2b8b67c 100644
--- a/src/buffer.rs
+++ b/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();
diff --git a/src/main.rs b/src/main.rs
index 5b64678..4bc85a4 100644
--- a/src/main.rs
+++ b/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 {

From 742ed978190e6271304d0a352cd31c3606b932ab Mon Sep 17 00:00:00 2001
From: mars <mars@tebibyte.media>
Date: Wed, 12 Apr 2023 17:50:14 -0400
Subject: [PATCH 2/6] Defer stdout flush until end of draw

---
 src/buffer.rs | 10 +++++-----
 src/main.rs   | 26 ++++++++++++++------------
 src/theme.rs  | 18 ++++++++----------
 3 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/src/buffer.rs b/src/buffer.rs
index 2b8b67c..80bf44b 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -21,7 +21,7 @@ use std::io::Write;
 use std::ops::Range;
 use std::sync::Arc;
 
-use crossterm::{cursor, ExecutableCommand};
+use crossterm::{cursor, ExecutableCommand, QueueableCommand};
 use parking_lot::Mutex;
 use ropey::Rope;
 use syntect::easy::ScopeRangeIterator;
@@ -74,7 +74,7 @@ impl Buffer {
         cols: u16,
         rows: u16,
         scroll: Cursor,
-        out: &mut (impl ExecutableCommand + Write),
+        out: &mut impl QueueableCommand,
     ) -> crossterm::Result<u32> {
         self.parse();
 
@@ -84,7 +84,7 @@ impl Buffer {
         let gutter_width = linenr_width + 1;
         let text_width = cols as usize - gutter_width as usize;
 
-        out.execute(cursor::MoveTo(0, 0))?;
+        out.queue(cursor::MoveTo(0, 0))?;
 
         for (row, line) in (0..rows).zip(self.text.lines_at(scroll.line)) {
             // only the last line is empty and should be skipped
@@ -117,7 +117,7 @@ impl Buffer {
                 }
             }
 
-            out.execute(cursor::MoveToNextLine(1))?;
+            out.queue(cursor::MoveToNextLine(1))?;
         }
 
         Ok(gutter_width)
@@ -157,7 +157,7 @@ impl Buffer {
             // parse the line into a sequence of stack operations
             let stack_ops = parser.parse_line(&line_buf, &self.syntax_set).unwrap();
 
-            // execute the operations on the stack
+            // queue the operations on the stack
             let mut line = Vec::new();
             let range_iter = ScopeRangeIterator::new(&stack_ops, &line_buf);
             for (range, op) in range_iter {
diff --git a/src/main.rs b/src/main.rs
index 4bc85a4..84e4936 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -31,7 +31,7 @@ use crossbeam_channel::Sender;
 use crossterm::{
     cursor,
     event::{Event, KeyCode, KeyEvent},
-    terminal, ExecutableCommand, Result,
+    terminal, Result, QueueableCommand,
 };
 use parking_lot::Mutex;
 use yacexits::{exit, EX_DATAERR, EX_UNAVAILABLE};
@@ -135,8 +135,8 @@ impl State {
     pub fn draw(&mut self, out: &mut impl Write) -> Result<()> {
         // begin update
         let (cols, rows) = terminal::size()?;
-        out.execute(terminal::BeginSynchronizedUpdate)?;
-        out.execute(terminal::Clear(terminal::ClearType::All))?;
+        out.queue(terminal::BeginSynchronizedUpdate)?;
+        out.queue(terminal::Clear(terminal::ClearType::All))?;
         let mut styles = self.styles.lock();
 
         // draw status line
@@ -147,14 +147,14 @@ impl State {
             Mode::Command(CommandState { buf, cursor }) => {
                 let col = *cursor as u16 + 1;
                 let row = rows - 1;
-                out.execute(cursor::MoveTo(0, row))?;
+                out.queue(cursor::MoveTo(0, row))?;
                 write!(out, ":{}", buf)?;
                 set_cursor_pos = Some((col, row));
                 show_status_bar = true;
             }
             Mode::Normal(NormalState { error: Some(error) }) => {
                 let error_style = styles.get_scope("error");
-                out.execute(cursor::MoveTo(0, rows - 1))?;
+                out.queue(cursor::MoveTo(0, rows - 1))?;
                 error_style.print_styled(out, error)?;
                 show_status_bar = true;
             }
@@ -178,11 +178,13 @@ impl State {
             (col, row)
         });
 
-        out.execute(cursor::MoveTo(cursor_pos.0, cursor_pos.1))?;
-        out.execute(self.mode.cursor_style())?;
+        out.queue(cursor::MoveTo(cursor_pos.0, cursor_pos.1))?;
+        out.queue(self.mode.cursor_style())?;
 
         // finish update
-        out.execute(terminal::EndSynchronizedUpdate)?;
+        out.queue(terminal::EndSynchronizedUpdate)?;
+        out.flush()?;
+
         Ok(())
     }
 
@@ -246,7 +248,7 @@ impl State {
                 }
                 KeyCode::Enter => {
                     // TODO add to command history
-                    let result = self.execute_command(&state.buf);
+                    let result = self.queue_command(&state.buf);
                     let error = result.err();
                     self.mode = Mode::Normal(NormalState { error });
                     return;
@@ -347,7 +349,7 @@ impl State {
         self.write_buffer(handle).map_err(|err| format!("{}", err))
     }
 
-    fn execute_command(&mut self, command: &str) -> std::result::Result<(), String> {
+    fn queue_command(&mut self, command: &str) -> std::result::Result<(), String> {
         let command_parts = command.split(' ').collect::<Vec<&str>>();
 
         let command = match command_parts.get(0) {
@@ -457,9 +459,9 @@ fn main() -> Result<()> {
     let state = State::from_str(file_name, &text)?;
     let mut stdout = stdout();
     terminal::enable_raw_mode()?;
-    stdout.execute(terminal::EnterAlternateScreen)?;
+    stdout.queue(terminal::EnterAlternateScreen)?;
     let result = screen_main(&mut stdout, state);
-    stdout.execute(terminal::LeaveAlternateScreen)?;
+    stdout.queue(terminal::LeaveAlternateScreen)?;
     terminal::disable_raw_mode()?;
     result
 }
diff --git a/src/theme.rs b/src/theme.rs
index 3723a10..b9eadb4 100644
--- a/src/theme.rs
+++ b/src/theme.rs
@@ -17,11 +17,10 @@
  * along with this program. If not, see https://www.gnu.org/licenses/.
  */
 
-use std::io::Write;
 use std::{collections::HashMap, fmt::Display};
 
-use crossterm::{style::Color, ExecutableCommand};
-use once_cell::sync::Lazy;
+use crossterm::style::Color;
+use crossterm::QueueableCommand;
 use toml::{map::Map, Value};
 
 #[derive(Debug, Default)]
@@ -110,22 +109,21 @@ pub struct Style {
 impl Style {
     pub fn print_styled(
         &self,
-        out: &mut (impl ExecutableCommand + Write),
+        out: &mut impl QueueableCommand,
         content: impl Display,
     ) -> crossterm::Result<()> {
-        use crossterm::style::{ResetColor, SetBackgroundColor, SetForegroundColor};
+        use crossterm::style::{Print, ResetColor, SetBackgroundColor, SetForegroundColor};
 
         if let Some(fg) = self.fg {
-            out.execute(SetForegroundColor(fg))?;
+            out.queue(SetForegroundColor(fg))?;
         }
 
         if let Some(bg) = self.bg {
-            out.execute(SetBackgroundColor(bg))?;
+            out.queue(SetBackgroundColor(bg))?;
         }
 
-        write!(out, "{}", content)?;
-
-        out.execute(ResetColor)?;
+        out.queue(Print(content))?;
+        out.queue(ResetColor)?;
 
         Ok(())
     }

From 83872583e086255fa84c093a0954ee0db8dfbc3a Mon Sep 17 00:00:00 2001
From: mars <mars@tebibyte.media>
Date: Wed, 12 Apr 2023 17:54:22 -0400
Subject: [PATCH 3/6] Buffer line styling

---
 src/buffer.rs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/buffer.rs b/src/buffer.rs
index 80bf44b..92f767a 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -74,7 +74,7 @@ impl Buffer {
         cols: u16,
         rows: u16,
         scroll: Cursor,
-        out: &mut impl QueueableCommand,
+        out: &mut impl Write,
     ) -> crossterm::Result<u32> {
         self.parse();
 
@@ -86,6 +86,7 @@ impl Buffer {
 
         out.queue(cursor::MoveTo(0, 0))?;
 
+        let mut line_buf = Vec::<u8>::with_capacity(text_width);
         for (row, line) in (0..rows).zip(self.text.lines_at(scroll.line)) {
             // only the last line is empty and should be skipped
             if line.len_chars() == 0 {
@@ -98,6 +99,7 @@ impl Buffer {
 
             let lhs = scroll.column;
             let width = line.len_chars();
+            line_buf.clear();
             if lhs < width {
                 let window = text_width.min(width - lhs);
                 let rhs = lhs + window;
@@ -107,7 +109,7 @@ impl Buffer {
                     if range.start < range.end {
                         // this range is in view so display
                         let content = line.slice(range.clone());
-                        style.print_styled(out, content)?;
+                        style.print_styled(&mut line_buf, content)?;
                     }
 
                     if range.end >= rhs {
@@ -117,6 +119,7 @@ impl Buffer {
                 }
             }
 
+            out.write_all(&line_buf)?;
             out.queue(cursor::MoveToNextLine(1))?;
         }
 

From 4f6f17d066e08dc9775ba4aa4c537df87f207801 Mon Sep 17 00:00:00 2001
From: mars <mars@tebibyte.media>
Date: Wed, 12 Apr 2023 18:03:25 -0400
Subject: [PATCH 4/6] Oops! accidentally set dirty flag every draw

---
 src/buffer.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/buffer.rs b/src/buffer.rs
index 92f767a..4e94f65 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -183,7 +183,7 @@ impl Buffer {
             self.styled.push(line);
         }
 
-        self.style_dirty = true;
+        self.style_dirty = false;
         self.style_generation = styles.generation();
     }
 

From b351dbbcbb199cf1b6135130e679a83198b23a29 Mon Sep 17 00:00:00 2001
From: mars <mars@tebibyte.media>
Date: Wed, 12 Apr 2023 18:24:06 -0400
Subject: [PATCH 5/6] Faster syntax highlighting with a style stack

---
 src/buffer.rs | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/src/buffer.rs b/src/buffer.rs
index 4e94f65..95926ab 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -25,7 +25,7 @@ use crossterm::{cursor, ExecutableCommand, QueueableCommand};
 use parking_lot::Mutex;
 use ropey::Rope;
 use syntect::easy::ScopeRangeIterator;
-use syntect::parsing::{ParseState, Scope, ScopeStack, SyntaxSet};
+use syntect::parsing::{BasicScopeStackOp, ParseState, Scope, ScopeStack, SyntaxSet};
 
 use crate::theme::{Style, StyleStore};
 use crate::{Cursor, Direction};
@@ -150,6 +150,8 @@ impl Buffer {
         let mut parser = self.parser.clone();
         let mut line_buf = String::new();
         let mut stack = ScopeStack::new();
+        let mut style_stack = Vec::<Style>::new();
+        let mut styled_buf = Vec::new();
         for line in self.text.lines() {
             // display line to a pre-allocated buffer for fast parsing
             line_buf.clear();
@@ -161,26 +163,31 @@ impl Buffer {
             let stack_ops = parser.parse_line(&line_buf, &self.syntax_set).unwrap();
 
             // queue the operations on the stack
-            let mut line = Vec::new();
             let range_iter = ScopeRangeIterator::new(&stack_ops, &line_buf);
+            styled_buf.clear();
             for (range, op) in range_iter {
-                stack.apply(&op).unwrap();
+                stack
+                    .apply_with_hook(&op, |op, _scopes| match op {
+                        BasicScopeStackOp::Push(scope) => {
+                            let scope = scope.build_string();
+                            let style = styles.get_scope(&scope);
+                            style_stack.push(style);
+                        }
+                        BasicScopeStackOp::Pop => {
+                            style_stack.pop();
+                        }
+                    })
+                    .unwrap();
 
                 if range.start == range.end {
                     continue;
                 }
 
-                let mut style = Style::default();
-                for scope in stack.scopes.clone() {
-                    // TODO docs say that build_string "shouldn't be done frequently"
-                    let scope = scope.build_string();
-                    style.apply(&styles.get_scope(&scope));
-                }
-
-                line.push((style, range));
+                let style = style_stack.last().cloned().unwrap_or_default();
+                styled_buf.push((style, range));
             }
 
-            self.styled.push(line);
+            self.styled.push(styled_buf.clone());
         }
 
         self.style_dirty = false;

From 814d4b116bd2c5ac45586c63cb20e1de2749d4c4 Mon Sep 17 00:00:00 2001
From: mars <mars@tebibyte.media>
Date: Wed, 12 Apr 2023 18:38:12 -0400
Subject: [PATCH 6/6] More efficient scope style lookups

---
 src/buffer.rs | 12 ++++++++----
 src/theme.rs  | 52 ++++++++++++++++++++++++++++++++++++---------------
 2 files changed, 45 insertions(+), 19 deletions(-)

diff --git a/src/buffer.rs b/src/buffer.rs
index 95926ab..b8a8be2 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -150,8 +150,11 @@ impl Buffer {
         let mut parser = self.parser.clone();
         let mut line_buf = String::new();
         let mut stack = ScopeStack::new();
-        let mut style_stack = Vec::<Style>::new();
         let mut styled_buf = Vec::new();
+
+        let mut style_stack = Vec::<Style>::new();
+        style_stack.push(Default::default());
+
         for line in self.text.lines() {
             // display line to a pre-allocated buffer for fast parsing
             line_buf.clear();
@@ -169,9 +172,10 @@ impl Buffer {
                 stack
                     .apply_with_hook(&op, |op, _scopes| match op {
                         BasicScopeStackOp::Push(scope) => {
-                            let scope = scope.build_string();
-                            let style = styles.get_scope(&scope);
-                            style_stack.push(style);
+                            let style = styles.get_syntect_scope(&scope);
+                            let mut top_style = style_stack.last().unwrap().clone();
+                            top_style.apply(style);
+                            style_stack.push(top_style);
                         }
                         BasicScopeStackOp::Pop => {
                             style_stack.pop();
diff --git a/src/theme.rs b/src/theme.rs
index b9eadb4..a9758b7 100644
--- a/src/theme.rs
+++ b/src/theme.rs
@@ -21,6 +21,7 @@ use std::{collections::HashMap, fmt::Display};
 
 use crossterm::style::Color;
 use crossterm::QueueableCommand;
+use syntect::parsing::Scope;
 use toml::{map::Map, Value};
 
 #[derive(Debug, Default)]
@@ -34,6 +35,9 @@ pub struct StyleStore {
     /// Maps named scopes to indices.
     scopes: HashMap<String, usize>,
 
+    /// Maps syntect scopes to indices.
+    syntect_scopes: HashMap<Scope, usize>,
+
     /// The style data store.
     styles: Vec<Style>,
 }
@@ -45,41 +49,59 @@ impl StyleStore {
             theme,
             generation: 0,
             scopes: HashMap::new(),
+            syntect_scopes: HashMap::new(),
             styles: Vec::new(),
         }
     }
 
     /// Adds a scope to this store and returns its index. Reuses indices for existing scopes.
     pub fn add_scope(&mut self, scope: &str) -> usize {
-        let style = self.theme.get_scope_style(scope);
-
-        if let Some(style_idx) = self.scopes.get(scope).copied() {
-            let old_style = self
-                .styles
-                .get_mut(style_idx)
-                .expect("StyleStore index is out-of-bounds");
-            let _ = std::mem::replace(old_style, style);
-            style_idx
+        if let Some(style_idx) = self.scopes.get(scope) {
+            *style_idx
         } else {
             let style_idx = self.styles.len();
+            let style = self.theme.get_scope_style(scope);
             self.styles.push(style);
             self.scopes.insert(scope.to_string(), style_idx);
+
+            if let Ok(scope) = Scope::new(scope) {
+                self.syntect_scopes.insert(scope, style_idx);
+            }
+
             style_idx
         }
     }
 
     /// Gets the style for a scope by name.
-    pub fn get_scope(&mut self, scope: &str) -> Style {
+    pub fn get_scope(&mut self, scope: &str) -> &Style {
         let idx = self.add_scope(scope);
         self.get_style(idx)
     }
 
+    /// Adds a Syntect [Scope] and returns its index. Resues indices for existing scopes.
+    pub fn add_syntect_scope(&mut self, scope: &Scope) -> usize {
+        if let Some(style_idx) = self.syntect_scopes.get(scope) {
+            *style_idx
+        } else {
+            let style_idx = self.styles.len();
+            let scope_str = scope.build_string();
+            let style = self.theme.get_scope_style(&scope_str);
+            self.styles.push(style);
+            self.scopes.insert(scope_str, style_idx);
+            self.syntect_scopes.insert(*scope, style_idx);
+            style_idx
+        }
+    }
+
+    /// Gets the style for a Syntect [Scope].
+    pub fn get_syntect_scope(&mut self, scope: &Scope) -> &Style {
+        let idx = self.add_syntect_scope(scope);
+        self.get_style(idx)
+    }
+
     /// Gets the style for a scope index. Panics if out-of-bounds.
-    pub fn get_style(&self, index: usize) -> Style {
-        self.styles
-            .get(index)
-            .expect("StyleStore is out-of-bounds")
-            .to_owned()
+    pub fn get_style(&self, index: usize) -> &Style {
+        self.styles.get(index).expect("StyleStore is out-of-bounds")
     }
 
     /// The current generation of the store. Increments every update.