Method fmt

cranelift/isle/isle/src/error.rs:15–80

(&self, f: &mut std::fmt::Formatter)

impl std::fmt::Debug for Errors {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        if self.errors.is_empty() {
            return Ok(());
        }
        let diagnostics = Vec::from_iter(self.errors.iter().map(|e| {
            let message = match e {
                Error::IoError { context, .. } => context.clone(),
                Error::ParseError { msg, .. } => format!("parse error: {msg}"),
                Error::TypeError { msg, .. } => format!("type error: {msg}"),
                Error::UnreachableError { msg, .. } => format!("unreachable rule: {msg}"),
                Error::OverlapError { msg, .. } => format!("overlap error: {msg}"),
                Error::RecursionError { msg, .. } => format!("recursion error: {msg}"),
                Error::ShadowedError { .. } => {
                    "more general higher-priority rule shadows other rules".to_string()
                }
            };

            let labels = match e {
                Error::IoError { .. } => vec![],

                Error::ParseError { span, .. }
                | Error::TypeError { span, .. }
                | Error::UnreachableError { span, .. }
                | Error::RecursionError { span, .. } => {
                    vec![Label::primary(span.from.file, span)]
                }

                Error::OverlapError { rules, .. } => {
                    let mut labels = vec![Label::primary(rules[0].from.file, &rules[0])];
                    labels.extend(
                        rules[1..]
                            .iter()
                            .map(|span| Label::secondary(span.from.file, span)),
                    );
                    labels
                }

                Error::ShadowedError { shadowed, mask } => {
                    let mut labels = vec![Label::primary(mask.from.file, mask)];
                    labels.extend(
                        shadowed
                            .iter()
                            .map(|span| Label::secondary(span.from.file, span)),
                    );
                    labels
                }
            };

            let mut sources = Vec::new();
            let mut source = e.source();
            while let Some(e) = source {
                sources.push(format!("{e:?}"));
                source = std::error::Error::source(e);
            }

            Diagnostic::error()
                .with_message(message)
                .with_labels(labels)