add support for errfmt friendly output

bin/src/main.rs

@@ -49,7 +49,7 @@ fn _main() -> Result<(), StatixErr> {
 
             let mut stderr = io::stderr();
             lint_results.for_each(|r| {
-                stderr.write(&r, &vfs).unwrap();
+                stderr.write(&r, &vfs, lint_config.format).unwrap();
             });
             errors.for_each(|e| {
                 eprintln!("{}", e);

bin/src/traits.rs

@@ -3,7 +3,7 @@ use std::{
     str,
 };
 
-use crate::lint::LintResult;
+use crate::{config::OutFormat, lint::LintResult};
 
 use ariadne::{
     CharSet, Color, Config as CliConfig, Fmt, Label, LabelAttach, Report as CliReport,
@@ -13,14 +13,37 @@ use rnix::TextRange;
 use vfs::ReadOnlyVfs;
 
 pub trait WriteDiagnostic {
-    fn write(&mut self, report: &LintResult, vfs: &ReadOnlyVfs) -> io::Result<()>;
+    fn write(
+        &mut self,
+        report: &LintResult,
+        vfs: &ReadOnlyVfs,
+        format: OutFormat,
+    ) -> io::Result<()>;
 }
 
 impl<T> WriteDiagnostic for T
 where
     T: Write,
 {
-    fn write(&mut self, lint_result: &LintResult, vfs: &ReadOnlyVfs) -> io::Result<()> {
+    fn write(
+        &mut self,
+        lint_result: &LintResult,
+        vfs: &ReadOnlyVfs,
+        format: OutFormat,
+    ) -> io::Result<()> {
+        match format {
+            OutFormat::StdErr => write_stderr(self, lint_result, vfs),
+            OutFormat::Errfmt => write_errfmt(self, lint_result, vfs),
+            _ => Ok(()),
+        }
+    }
+}
+
+fn write_stderr<T: Write>(
+    writer: &mut T,
+    lint_result: &LintResult,
+    vfs: &ReadOnlyVfs,
+) -> io::Result<()> {
     let file_id = lint_result.file_id;
     let src = str::from_utf8(vfs.get(file_id)).unwrap();
     let path = vfs.file_path(file_id);
@@ -56,10 +79,42 @@ where
                 },
             )
             .finish()
-                .write((src_id, Source::from(src)), &mut *self)?;
+            .write((src_id, Source::from(src)), &mut *writer)?;
     }
     Ok(())
 }
+
+fn write_errfmt<T: Write>(writer: &mut T, lint_result: &LintResult, vfs: &ReadOnlyVfs) -> io::Result<()> {
+    let file_id = lint_result.file_id;
+    let src = str::from_utf8(vfs.get(file_id)).unwrap();
+    let path = vfs.file_path(file_id);
+    for report in lint_result.reports.iter() {
+        for diagnostic in report.diagnostics.iter() {
+            let line = line(diagnostic.at, &src);
+            let col = column(diagnostic.at, &src);
+            writeln!(
+                writer,
+                "{filename}>{linenumber}:{columnnumber}:{errortype}:{errornumber}:{errormessage}",
+                filename = path.to_str().unwrap_or("<unknown>"),
+                linenumber = line,
+                columnnumber = col,
+                errortype = "W",
+                errornumber = report.code,
+                errormessage = diagnostic.message
+            )?;
+        }
+    }
+    Ok(())
+}
+
+fn line(at: TextRange, src: &str) -> usize {
+    let at = at.start().into();
+    src[..at].chars().filter(|&c| c == '\n').count() + 1
+}
+
+fn column(at: TextRange, src: &str) -> usize {
+    let at = at.start().into();
+    src[..at].rfind('\n').map(|c| at - c).unwrap_or(at + 1)
 }
 
 // everything within backticks is colorized, backticks are removed