less broken multiline editing

4 files changed, 42 insertions, 35 deletions

diff --git a/src/cursor.rs b/src/cursor.rs
index 959b15f..e6f99f1 100644
--- a/src/cursor.rs
+++ b/src/cursor.rs
@@ -27,12 +27,20 @@ pub fn move_cursor(direction: Direction, n: usize) {
     fmove_cursor(direction, n, &mut std::io::stdout()).unwrap()
 }
 
+pub fn f_save(stdout: &mut dyn Write) -> std::io::Result<()> {
+    stdout.write_all(b"\x1b[s")
+}
+
+pub fn f_restore(stdout: &mut dyn Write) -> std::io::Result<()> {
+    stdout.write_all(b"\x1b[u")
+}
+
 pub fn save() {
-    std::io::stdout().lock().write_all(b"\x1b[s").unwrap();
+    f_save(&mut std::io::stdout().lock()).unwrap();
 }
 
 pub fn restore() {
-    std::io::stdout().lock().write_all(b"\x1b[u").unwrap();
+    f_restore(&mut std::io::stdout().lock()).unwrap();
 }
 
 /// Represents a cursor position
diff --git a/src/lib.rs b/src/lib.rs
index 93d9cb8..314f12c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -431,6 +431,7 @@ pub fn event_loop() {
                         drop(se);
                         // not sure if/how to report this error - would be strange to print something to console every time a keybind command returns nonzero exit code.
                         let _ = run::run_quiet(session.clone(), cmd);
+                        session.lock().unwrap().cohere().unwrap();
                         continue 'repl;
                     }
                 }
diff --git a/src/line/mod.rs b/src/line/mod.rs
index c6c2f34..510c480 100644
--- a/src/line/mod.rs
+++ b/src/line/mod.rs
@@ -36,15 +36,15 @@ impl Line {
     }
 
     pub fn highlight_syntax(&mut self, h: &mut Highlighter) -> std::io::Result<()> {
-        if !self.is_dirty() {
+        if !self.dirty {
             return Ok(());
         }
+        self.dirty = false;
 
-        self.mark_clean();
-
-        if !h.enabled {
-            return Ok(());
-        }
+        // TODO this is currently needed to reprint the prompt upon modification so we can't skip it.
+        // if !h.enabled {
+        //     return Ok(());
+        // }
 
         use crate::parse::{self, Parse};
 
@@ -53,7 +53,7 @@ impl Line {
         let _ = parse::Ast::parse(&mut parser);
         let mut stdout = io::stdout().lock();
         self.line_start.f_go_to(&mut stdout)?;
-        h.pretty_print(&buf, parser.highlights, &mut stdout)?;
+        h.pretty_print(&buf, self.left_len(), parser.highlights, &mut stdout)?;
         stdout.flush()?;
 
         Ok(())
@@ -159,8 +159,9 @@ macro_rules! mutating_impls {
     ($(pub fn $fun:ident(&mut $self:ident $($arg:tt)*) -> $ty:ty $body:block )*) => {
         impl Line {$(
             pub fn $fun(&mut $self $($arg)*) -> $ty {
+                let result = $body;
                 $self.dirty = true;
-                $body
+                result
             }
         )*}
     };
@@ -168,25 +169,14 @@ macro_rules! mutating_impls {
 
 mutating_impls! {
     pub fn clear_prompt(&mut self) -> io::Result<()> {
-        let mut stdout = io::stdout().lock();
-        cursor::fmove_cursor(
-            Direction::Right,
-            self.buf.distance_from_right_end(),
-            &mut stdout,
-        )?;
-        for _ in 0..self.buf.len() {
-            stdout.write_all(b"\x08 \x08")?;
-        }
         self.buf.clear();
-        stdout.flush()
+        Ok(())
     }
 
     pub fn type_bytes(&mut self, bs: &[u8]) -> io::Result<()> {
         for b in bs.iter() {
             self.buf.add(*b);
         }
-        io::stdout().lock().write_all(&bs)?;
-        self.buf.display_post(b"");
         Ok(())
     }
 
@@ -196,52 +186,43 @@ mutating_impls! {
 
     pub fn del_left(&mut self) -> io::Result<()> {
         if self.buf.del_left().is_some() {
-            cursor::fmove_cursor(Direction::Left, 1, &mut io::stdout())?;
-            self.buf.display_post(b" ");
+            let mut stdout = io::stdout().lock();
+            cursor::fmove_cursor(Direction::Left, 1, &mut stdout)?;
+            stdout.flush()?;
         }
         Ok(())
     }
 
     pub fn del_right(&mut self) -> io::Result<()> {
         self.buf.del_right();
-        self.buf.display_post(b" ");
         Ok(())
     }
 
     pub fn del_left_word(&mut self) -> io::Result<()> {
-        let mut del = 0;
         while let Some(x) = self.buf.get_left()
             && x == b' '
         {
             self.buf.del_left();
-            del += 1;
         }
         while let Some(x) = self.buf.get_left()
             && x != b' '
         {
             self.buf.del_left();
-            del += 1;
         }
-        cursor::fmove_cursor(Direction::Left, del, &mut io::stdout())?;
-        self.buf.display_post(&vec![b' '; del]);
         Ok(())
     }
 
     pub fn del_right_word(&mut self) -> io::Result<()> {
-        let mut del = 0;
         while let Some(x) = self.buf.get_right()
             && x == b' '
         {
             self.buf.del_right();
-            del += 1;
         }
         while let Some(x) = self.buf.get_right()
             && x != b' '
         {
             self.buf.del_right();
-            del += 1;
         }
-        self.buf.display_post(&vec![b' '; del]);
         Ok(())
     }
 
diff --git a/src/syntax_highlighting.rs b/src/syntax_highlighting.rs
index 043509a..19f44ab 100644
--- a/src/syntax_highlighting.rs
+++ b/src/syntax_highlighting.rs
@@ -1,7 +1,7 @@
 use std::collections::HashMap;
 
 use crate::{
-    BString, ansi, bstr,
+    BString, ansi, bstr, cursor,
     parse::{Highlight, HighlightKind},
 };
 
@@ -15,6 +15,8 @@ pub enum SetColorError {
     NoSuchKeyword,
 }
 
+const CLEAR_TO_END: &bstr = b"\x1b[K";
+
 impl Highlighter {
     pub fn new() -> Self {
         let mut this = Self {
@@ -51,6 +53,7 @@ impl Highlighter {
     pub fn pretty_print(
         &self,
         bytes: &[u8],
+        cursor_offset: usize,
         colors: Vec<Highlight>,
         stdout: &mut dyn std::io::Write,
     ) -> std::io::Result<()> {
@@ -104,7 +107,16 @@ impl Highlighter {
 
         let mut current_color = self.color(HighlightKind::None);
 
+        let mut saved_pos = false;
+
+        stdout.write_all(CLEAR_TO_END)?;
+
         for (i, x) in bytes.iter().cloned().enumerate() {
+            if i == cursor_offset {
+                cursor::f_save(stdout)?;
+                saved_pos = true;
+            }
+
             while let Some(color_boundary) = coloring.first().cloned()
                 && color_boundary.loc <= i
             {
@@ -126,6 +138,7 @@ impl Highlighter {
 
             if x == b'\n' {
                 stdout.write_all(b"\r\n")?;
+                stdout.write_all(CLEAR_TO_END)?;
             } else {
                 stdout.write_all(&[x])?;
             }
@@ -133,6 +146,10 @@ impl Highlighter {
 
         stdout.write_all(self.color(HighlightKind::None))?;
 
+        if saved_pos {
+            cursor::f_restore(stdout)?;
+        }
+
         Ok(())
     }
 }