moving output writing to one spot

src/error.rs

@@ -31,3 +31,12 @@ impl Error {
         Error::InputError(msg.into())
     }
 }
+
+impl From<Error> for std::io::Error {
+    fn from(e: Error) -> Self {
+        match e {
+            Error::IOError(e) => e,
+            _ => std::io::Error::new(std::io::ErrorKind::Other, e),
+        }
+    }
+}

src/main.rs

@@ -1,5 +1,6 @@
 mod error;
 mod input;
+mod output;
 mod key;
 mod line;
 mod log;
@@ -8,9 +9,9 @@ mod prompt;
 use line::Line;
 use prompt::Prompt;
 use std::fs::File;
-use std::io::{Read, Seek, SeekFrom};
+use std::io::{Read, Seek, SeekFrom, Write};
 use windows::Win32::{
-    Foundation::{CloseHandle, HANDLE},
+    Foundation::HANDLE,
     System::Console,
 };
 
@@ -275,6 +276,7 @@ fn main() -> Result<()> {
     let mut line = Line::new();
     let prompt = Prompt::new();
     let mut input = input::Reader::new()?;
+    let mut output = output::Writer::new()?;
 
     prompt.print()?;
     info!("» enter");
@@ -318,35 +320,21 @@ fn main() -> Result<()> {
 
                 if event.code == key::BACKSPACE {
                     if line.backspace() {
-                        unsafe {
-                            // move cursor back two spaces
-                            Error::check(Console::WriteConsoleA(stdout, "\x1b[2D".as_bytes(), None, None))?;
-                        }
+                        // move cursor back two spaces
+                        output.write("\x1b[2D")?;
+                        // output.back(2)?;
                         let tail = format!("{} ", line.tail());
                         let n = tail.chars().count();
-                        unsafe {
-                            // write the rest of the line plus a space to erase the last character
-                            Error::check(Console::WriteConsoleA(
-                                stdout,
-                                tail.as_bytes(),
-                                None,
-                                None,
-                            ))?;
-                        }
+                        output.write(&tail)?;
 
                         // after writing out the tail, rewind by the number of characters in
                         // the tail
                         if n > 1 {
                             let text = format!("\x1b[{}D", n-1);
-                            unsafe {
-                                Error::check(Console::WriteConsoleA(stdout, text.as_bytes(), None, None))?;
-                            }
+                            output.write(&text)?;
                         } else {
                             // honestly I can't remember how I figured this out
-                            let text = format!(" \x1b[1D");
-                            unsafe {
-                                Error::check(Console::WriteConsoleA(stdout, text.as_bytes(), None, None))?;
-                            }
+                            output.write(" \x1b[1D")?;
                         }
                     }
                     continue;
@@ -355,34 +343,24 @@ fn main() -> Result<()> {
                 // CTRL-D to exit
                 if event.ctrl && event.code == key::D {
                     info!("» exit");
-                    unsafe {
-                        CloseHandle(stdout);
-                    }
+                    output.close()?;
                     return Ok(());
                 }
 
                 // CTRL-J to draw a cool little dot
                 if event.ctrl && event.code == key::J {
                     debug!("⎈ j: dot");
-                    unsafe {
-                        // red bullet
-                        let text = "\x1b[31m\u{2022}\x1b[0m";
-                        Error::check(Console::WriteConsoleA(stdout, text.as_bytes(), None, None))?;
-                    }
+                    // red bullet
+                    output.write("\x1b[31m\u{2022}\x1b[0m")?;
                     continue;
                 }
 
                 // CTRL-L to clear the screen
                 if event.ctrl && event.code == key::L {
                     info!("» clear");
-                    let text = "\x1b[2J\x1b[0;0H";
-                    unsafe {
-                        Error::check(Console::WriteConsoleA(stdout, text.as_bytes(), None, None))?;
-                    }
+                    output.write("\x1b[2J\x1b[0;0H")?;
                     prompt.print()?;
-                    unsafe {
-                        Error::check(Console::WriteConsoleA(stdout, line.show().as_bytes(), None, None))?;
-                    }
+                    output.write(&line.show())?;
                     continue;
                 }
 

src/output.rs

@@ -0,0 +1,52 @@
+use anyhow::{Context, Result};
+use crate::error::Error;
+use windows::Win32::{Foundation::{CloseHandle, HANDLE}, System::Console};
+// use std::io;
+
+
+pub fn stdout_handle() -> Result<HANDLE> {
+    unsafe {
+        let handle = Console::GetStdHandle(Console::STD_OUTPUT_HANDLE)
+            .context("unable to get stdin handle")?;
+        Ok(handle)
+    }
+}
+
+pub struct Writer {
+    output: HANDLE,
+}
+
+impl Writer {
+    pub fn new() -> Result<Self> {
+        Ok(Self{
+            output: stdout_handle()?,
+        })
+    }
+
+    pub fn write(&mut self, s: &str) -> Result<()> {
+        unsafe {
+            Error::check(Console::WriteConsoleA(self.output, s.as_bytes(), None, None))?;
+        }
+        Ok(())
+    }
+
+    pub fn close(&mut self) -> Result<()> {
+        unsafe {
+            CloseHandle(self.output);
+        }
+        Ok(())
+    }
+}
+
+// impl std::io::Write for Writer {
+//     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+//         unsafe {
+//             Error::check(Console::WriteConsoleA(self.output, buf, None, None))?;
+//         }
+//         Ok(0)
+//     }
+// 
+//     fn flush(&mut self) -> io::Result<()> {
+//         Ok(())
+//     }
+// }