fix: use stderr for diagnostic data (#782)

Author: magistau

src/compile/algebra.rs

@@ -17,7 +17,7 @@ pub const DEBUG: bool = false;
 macro_rules! dbgln {
     ($($arg:tt)*) => {
         if DEBUG {
-            println!($($arg)*); // Allow println
+            eprintln!($($arg)*);
         }
     }
 }

src/compile/invert/mod.rs

@@ -32,7 +32,7 @@ pub(crate) const DEBUG: bool = false;
 macro_rules! dbgln {
     ($($arg:tt)*) => {
         if crate::compile::invert::DEBUG {
-            println!($($arg)*); // Allow println
+            eprintln!($($arg)*);
         }
     }
 }

src/compile/mod.rs

@@ -2606,7 +2606,7 @@ impl Compiler {
     }
     fn emit_diagnostic_impl(&mut self, diagnostic: Diagnostic) {
         if self.print_diagnostics {
-            println!("{}", diagnostic.report()); // Allow println
+            eprintln!("{}", diagnostic.report());
         } else {
             self.diagnostics.insert(diagnostic);
         }

src/compile/optimize.rs

@@ -7,7 +7,7 @@ pub(crate) const DEBUG: bool = false;
 macro_rules! dbgln {
     ($($arg:tt)*) => {
         if DEBUG {
-            println!($($arg)*); // Allow println
+            eprintln!($($arg)*);
         }
     }
 }

src/main.rs

@@ -36,7 +36,7 @@ static PRESSED_CTRL_C: AtomicBool = AtomicBool::new(false);
 static WATCH_CHILD: Lazy<Mutex<Option<Child>>> = Lazy::new(Default::default);
 
 fn fail<T>(e: UiuaError) -> T {
-    println!("{}", e.report());
+    eprintln!("{}", e.report());
     exit(1)
 }
 
@@ -72,7 +72,7 @@ fn main() {
         if let Some(ch) = &mut *child {
             _ = ch.kill();
             *child = None;
-            println!("# Program interrupted");
+            eprintln!("# Program interrupted");
             print_watching();
         } else {
             match App::try_parse().ok().and_then(|app| app.command) {
@@ -316,7 +316,7 @@ fn main() {
                     .load_file(path)
             });
             if let Err(e) = &res {
-                println!("{}", e.report());
+                eprintln!("{}", e.report());
             }
             rt.print_reports();
             if res.is_err() {
@@ -529,7 +529,7 @@ fn run(
         let res = rt.compile_run(|comp| comp.mode(mode).print_diagnostics(true).load_file(path));
         if let Err(e) = &res {
             print_stack(&rt.take_stack(), !no_color);
-            println!("{}", e.report());
+            eprintln!("{}", e.report());
         }
         rt.print_reports();
         if res.is_err() {
@@ -629,7 +629,7 @@ impl WatchArgs {
         let mut watcher = notify::recommended_watcher(send)?;
         watcher.watch(Path::new("."), RecursiveMode::Recursive)?;
 
-        println!("Watching for changes... (end with ctrl+C, use `uiua help` to see options)");
+        eprintln!("Watching for changes... (end with ctrl+C, use `uiua help` to see options)");
 
         let config = FormatConfig::from_source(format_config_source, initial_path.as_deref()).ok();
         #[cfg(feature = "audio")]
@@ -709,14 +709,14 @@ impl WatchArgs {
                             sleep(Duration::from_millis((i as u64 + 1) * 10))
                         } else {
                             clear_watching();
-                            println!("{}", e.report());
+                            eprintln!("{}", e.report());
                             print_watching();
                             return Ok(());
                         }
                     }
                 }
             }
-            println!("Failed to format file after {TRIES} tries");
+            eprintln!("Failed to format file after {TRIES} tries");
             Ok(())
         };
         if let Some(path) = initial_path {
@@ -1042,7 +1042,7 @@ fn clear_watching() {
 }
 
 fn clear_watching_with(s: &str, end: &str) {
-    print!(
+    eprint!(
         "\r{}{}",
         s.repeat(terminal_size::terminal_size().map_or(10, |(w, _)| w.0 as usize)),
         end,
@@ -1364,7 +1364,7 @@ fn update_modules(modules: &[PathBuf]) -> io::Result<()> {
         .collect::<io::Result<_>>()?;
     for (path, canonical) in modules.iter().zip(canonical) {
         env::set_current_dir(&canonical)?;
-        println!("{} {}", "Updating".bold().bright_green(), path.display());
+        eprintln!("{} {}", "Updating".bold().bright_green(), path.display());
         Command::new("git").args(["pull"]).spawn()?.wait()?;
     }
     Ok(())
@@ -1379,7 +1379,7 @@ fn check(path: Option<PathBuf>) -> UiuaResult {
         let message_length = format!("Checking {} ({}/{})", path.display(), i + 1, path_count)
             .chars()
             .count();
-        print!(
+        eprint!(
             "\r{} {} ({}/{}){}",
             "Checking".bold().bright_green(),
             path.display(),
@@ -1390,7 +1390,7 @@ fn check(path: Option<PathBuf>) -> UiuaResult {
         stdout().flush().unwrap();
         let mut comp = Compiler::with_backend(NativeSys);
         if let Err(e) = comp.load_file(path) {
-            println!("\n{}", e.report());
+            eprintln!("\n{}", e.report());
         } else {
             successes += 1;
         }
@@ -1410,7 +1410,7 @@ fn check(path: Option<PathBuf>) -> UiuaResult {
     } else {
         Color::BrightYellow
     };
-    println!(
+    eprintln!(
         "\r{}{}",
         message.color(color),
         " ".repeat(width.saturating_sub(message.chars().count()))

src/run.rs

@@ -276,7 +276,7 @@ impl Uiua {
     /// Print all pending reports
     pub fn print_reports(&mut self) {
         for report in self.take_reports() {
-            println!("{report}"); // Allow println
+            eprintln!("{report}");
         }
     }
     /// Take the assembly
@@ -793,8 +793,7 @@ impl Uiua {
         if self.rt.time_instrs {
             let end_time = self.rt.backend.now();
             let padding = self.rt.call_stack.len().saturating_sub(1) * 2;
-            #[rustfmt::skip]
-            println!( // Allow println
+            eprintln!(
                 "  ⏲{:padding$}{:.2}ms - {}",
                 "",
                 end_time - self.rt.last_time,

src/run_prim.rs

@@ -2052,7 +2052,7 @@ mod tests {
                     {
                         continue;
                     }
-                    println!("{prim} example:\n{}", ex.input); // Allow println
+                    eprintln!("{prim} example:\n{}", ex.input);
                     let mut env = Uiua::with_backend(SafeSys::with_thread_spawning());
                     match env.run_str(&ex.input) {
                         Ok(mut comp) => {

src/sys/native.rs

@@ -1215,17 +1215,16 @@ impl SysBackend for NativeSys {
             return Ok(true);
         }
         match env.span() {
-            #[rustfmt::skip]
-            Span::Code(span) => println!( // Allow println
+            Span::Code(span) => eprintln!(
                 "{} at {span} {}",
                 "&b".truecolor(237, 94, 106),
                 "(press enter to continue)".bright_black()
             ),
             Span::Builtin => {}
         }
-        println!(); // Allow println
+        eprintln!();
         print_stack(env.stack(), true);
-        println!(); // Allow println
+        eprintln!();
         _ = stdin().read_line(&mut String::new());
         Ok(true)
     }
@@ -1244,8 +1243,7 @@ pub fn print_stack(stack: &[Value], color: bool) {
         )
         .send();
         _ = Request::ClearBeforeNext.send();
-        #[rustfmt::skip]
-        println!( // Allow println
+        eprintln!(
             "{} value{} displayed in window",
             stack.len(),
             if stack.len() == 1 { "" } else { "s" }
@@ -1257,7 +1255,7 @@ pub fn print_stack(stack: &[Value], color: bool) {
     }
     if stack.len() == 1 || !color {
         for value in stack {
-            println!("{}", value.show()); // Allow println
+            eprintln!("{}", value.show());
         }
         return;
     }
@@ -1276,6 +1274,6 @@ pub fn print_stack(stack: &[Value], color: bool) {
             5 => (w, b, w),
             _ => unreachable!(),
         };
-        println!("{}", value.show().truecolor(r, g, b)); // Allow println
+        eprintln!("{}", value.show().truecolor(r, g, b));
     }
 }