Show source names in diagnostics

crates/decodal-cli/src/main.rs

@@ -4,19 +4,22 @@ use std::{
     process::ExitCode,
 };
 
-use decodal_core::{Data, Diagnostic, DiagnosticKind, Engine, LoadedSource, SourceLoader, Span};
+use decodal_core::{
+    Data, Diagnostic, DiagnosticKind, Engine, LoadedSource, SourceId, SourceLoader, Span,
+    format_diagnostic_with,
+};
 
 fn main() -> ExitCode {
     match run() {
         Ok(()) => ExitCode::SUCCESS,
         Err(error) => {
-            print_diagnostic(&error);
+            eprintln!("{error}");
             ExitCode::FAILURE
         }
     }
 }
 
-fn run() -> Result<(), Diagnostic> {
+fn run() -> Result<(), String> {
     let mut args = env::args().skip(1);
     let first = args.next().unwrap_or_else(|| String::from("--help"));
     match first.as_str() {
@@ -51,12 +54,19 @@ fn run() -> Result<(), Diagnostic> {
     }
 }
 
-fn materialize_path(path: &str) -> Result<Data, Diagnostic> {
-    let root = read_root_source(path)?;
+fn materialize_path(path: &str) -> Result<Data, String> {
+    let root = read_root_source(path).map_err(format_raw_diagnostic)?;
+    let root_name = root.name.clone();
     let mut engine = Engine::new(FsLoader);
-    let module = engine.add_root_source(root.key, root.name, &root.source)?;
-    let value = engine.eval_module(module)?;
-    engine.materialize(&value)
+    let module = engine
+        .add_root_source(root.key, root.name, &root.source)
+        .map_err(|error| format_diagnostic_with_root(&error, &root_name))?;
+    let value = engine
+        .eval_module(module)
+        .map_err(|error| engine.format_diagnostic(&error))?;
+    engine
+        .materialize(&value)
+        .map_err(|error| engine.format_diagnostic(&error))
 }
 
 fn read_root_source(path: &str) -> Result<LoadedSource, Diagnostic> {
@@ -139,24 +149,12 @@ fn print_help() {
     println!("  decodal -                  Read DCDL source from stdin");
 }
 
-fn print_diagnostic(error: &Diagnostic) {
-    eprintln!(
-        "error[{kind:?}] {source}:{start}..{end}: {message}",
-        kind = error.kind,
-        source = error.span.source.0,
-        start = error.span.start,
-        end = error.span.end,
-        message = error.message,
-    );
-    for label in &error.labels {
-        eprintln!(
-            "  note {source}:{start}..{end}: {message}",
-            source = label.span.source.0,
-            start = label.span.start,
-            end = label.span.end,
-            message = label.message,
-        );
-    }
+fn format_diagnostic_with_root(error: &Diagnostic, root_name: &str) -> String {
+    format_diagnostic_with(error, |source| (source == SourceId(0)).then_some(root_name))
+}
+
+fn format_raw_diagnostic(error: Diagnostic) -> String {
+    format_diagnostic_with(&error, |_| None)
 }
 
 fn print_data(data: &Data, indent: usize) {