removing useless escape sequences

src/main.rs

@@ -14,6 +14,7 @@ use std::io::Write;
 use anyhow::Result;
 
 use crate::log::*;
+use shell::Shell;
 
 fn main() -> Result<()> {
     match Log::file("C:\\Users\\JordanOrelli\\wash.log") {
@@ -30,6 +31,7 @@ fn main() -> Result<()> {
     let prompt = Prompt::new();
     let mut input = input::Reader::new()?;
     let mut output = output::Writer::new()?;
+    let shell = Shell::new();
 
     prompt.print(&mut output)?;
     info!("» enter");
@@ -58,7 +60,7 @@ fn main() -> Result<()> {
                             vec![]
                         };
                         debug!("◇ {} {}", cmd.clone(), args.join(" "));
-                        match shell::eval(&mut output, cmd.clone(), args.clone()) {
+                        match shell.eval(&mut output, cmd.clone(), args.clone()) {
                             Ok(true) => info!("▷ {} {}", cmd, args.join(" ")),
                             Ok(false) => warn!("▷ {} {}", cmd, args.join(" ")),
                             Err(e) => {
@@ -78,8 +80,7 @@ fn main() -> Result<()> {
                 if event.code == key::BACKSPACE {
                     if line.backspace() {
                         // move cursor back two spaces
-                        output.write(b"\x1b[2D")?;
+                        output.back(2)?;
-                        // output.back(2)?;
                         let tail = format!("{} ", line.tail());
                         let n = tail.chars().count();
                         output.write(tail.as_bytes())?;
@@ -87,8 +88,9 @@ fn main() -> Result<()> {
                         // after writing out the tail, rewind by the number of characters in
                         // the tail
                         if n > 1 {
-                            let text = format!("\x1b[{}D", n - 1);
+                            // let text = format!("\x1b[{}D", n - 1);
-                            output.write(text.as_bytes())?;
+                            output.back(n-1)?;
+                            // output.write(text.as_bytes())?;
                         } else {
                             // honestly I can't remember how I figured this out
                             output.write(b" \x1b[1D")?;
@@ -115,7 +117,7 @@ fn main() -> Result<()> {
                 // CTRL-L to clear the screen
                 if event.ctrl && event.code == key::L {
                     info!("» clear");
-                    output.write(b"\x1b[2J\x1b[0;0H")?;
+                    output.clear()?;
                     prompt.print(&mut output)?;
                     output.write(line.show().as_bytes())?;
                     continue;
@@ -127,15 +129,13 @@ fn main() -> Result<()> {
                     let n = line.clear_left();
                     if n > 0 {
                         // move left by the number of elements removed
-                        let text = format!("\x1b[{}D", n);
+                        output.back(n)?;
-                        output.write(text.as_bytes())?;
                         // draw the elements remaining, followed by a space for each removed
                         // element
                         let kept = line.show();
                         let text = format!("{}{:width$}", kept, "", width = n);
                         output.write(text.as_bytes())?;
-                        let text = format!("\x1b[{}D", n + kept.chars().count());
+                        output.back(n + kept.chars().count())?;
-                        output.write(text.as_bytes())?;
                     }
                     continue;
                 }
@@ -146,8 +146,7 @@ fn main() -> Result<()> {
                     let n = line.seek_left();
                     if n > 0 {
                         // move left by the distance seeked
-                        let text = format!("\x1b[{}D", n);
+                        output.back(n)?;
-                        output.write(text.as_bytes())?;
                     }
                     continue;
                 }
@@ -158,8 +157,7 @@ fn main() -> Result<()> {
                     let n = line.seek_right();
                     if n > 0 {
                         // move right by the distance seeked
-                        let text = format!("\x1b[{}C", n);
+                        output.forward(n)?;
-                        output.write(text.as_bytes())?;
                     }
                     continue;
                 }
@@ -177,8 +175,7 @@ fn main() -> Result<()> {
                     if n > 1 {
                         // if we wrote more than one character, because we weren't at the end, we
                         // need to rewind the terminal cursor to where it was.
-                        let text = format!("\x1b[{}D", n - 1);
+                        output.back(n-1)?;
-                        output.write(text.as_bytes())?;
                     }
                     continue;
                 }
@@ -188,13 +185,13 @@ fn main() -> Result<()> {
             input::Event::Left => {
                 debug!("⛬ ←");
                 if line.back() {
-                    output.write(b"\x1b[D")?; // lol this sucks
+                    output.back(1)?;
                 }
             }
             input::Event::Right => {
                 debug!("⛬ →");
                 if line.forward() {
-                    output.write(b"\x1b[C")?; // lol this sucks
+                    output.forward(1)?;
                 }
             }
             input::Event::Up => {

src/output.rs

@@ -143,6 +143,23 @@ impl Writer {
         self.write(b"\r\n")?;
         Ok(())
     }
+
+    pub fn back(&mut self, n: usize) -> Result<()> {
+        let text = format!("\x1b[{}D", n);
+        self.write(text.as_bytes())?;
+        Ok(())
+    }
+
+    pub fn forward(&mut self, n: usize) -> Result<()> {
+        let text = format!("\x1b[{}C", n);
+        self.write(text.as_bytes())?;
+        Ok(())
+    }
+
+    pub fn clear(&mut self) -> Result<()> {
+        self.write(b"\x1b[2J\x1b[0;0H")?;
+        Ok(())
+    }
 }
 
 impl Write for Writer {

src/shell.rs

@@ -4,7 +4,15 @@ use crate::output;
 
 use anyhow::Result;
 
-pub fn eval(output: &mut output::Writer, cmd: String, args: Vec<&str>) -> Result<bool> {
+pub struct Shell {
+}
+
+impl Shell {
+    pub fn new() -> Self {
+        Self {}
+    }
+
+    pub fn eval(&self, output: &mut output::Writer, cmd: String, args: Vec<&str>) -> Result<bool> {
         match cmd.as_str() {
             "pwd" => {
                 let pb = std::env::current_dir()?;
@@ -113,5 +121,5 @@ pub fn eval(output: &mut output::Writer, cmd: String, args: Vec<&str>) -> Result
                 return Ok(true);
             }
         }
+    }
 }
-