Struct ErrorMessage

pub struct ErrorMessage { /* private fields */ }

A single error message

Can take additional attachments like help or note.

Implements ToTokensError and can therefore be used with MacroOutputs.

Implementations

impl ErrorMessage

pub fn new(span: impl SpanRanged, msg: impl Display) -> Self

Creates a new error message at the specified span

This function takes a SpanRanged meaning you can also pass a Range<Span> (i.e. first..last) for better error messages on multi token values, for details see SpanRanged#motivation

If your type implements ToTokens use ErrorMessage::spanned instead.

pub fn spanned(tokens: impl ToTokens, msg: impl Display) -> Self

Creates an error message pointing to the complete token stream tokens expands to

pub fn call_site(msg: impl Display) -> Self

Creates a new error message at Span::call_site prefer ErrorMessage::new or ErrorMessage::spanned with the correct span for a more helpful output.

pub fn attachment(self, label: &'static str, msg: impl Display) -> Self

Attaches an additional message to self reusing the same span, and the specified label.

pub fn error(self, msg: impl Display) -> Self

Attaches a new error message to self reusing the same span

pub fn warning(self, msg: impl Display) -> Self

Attaches a new warning message to self reusing the same span

pub fn note(self, msg: impl Display) -> Self

Attaches a new note message to self reusing the same span

pub fn help(self, msg: impl Display) -> Self

Attaches a new help message to self reusing the same span

Trait Implementations

impl<T: ToTokensError + 'static> Add<T> for ErrorMessage

type Output = Error

The resulting type after applying the + operator.

fn add(self, rhs: T) -> Self::Output

Performs the + operation.

impl Attachment for ErrorMessage

fn attachment(self, label: &'static str, msg: impl Display) -> Self

Attaches an additional message to self reusing the same span, and the specified label.

impl Debug for ErrorMessage

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for ErrorMessage

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<ErrorMessage> for Error

fn from(error: ErrorMessage) -> Self

Converts to this type from the input type.

impl From<ErrorMessage> for Error

Available on crate feature syn1 only.

fn from(value: ErrorMessage) -> Self

Converts to this type from the input type.

impl From<ErrorMessage> for Error

Available on crate feature syn2 only.

fn from(value: ErrorMessage) -> Self

Converts to this type from the input type.

impl ToTokensError for ErrorMessage

fn to_tokens(&self, tokens: &mut TokenStream)

Equivalent to ToTokens::to_tokens

fn to_token_stream(&self) -> TokenStream

Equivalent to ToTokens::to_token_stream

fn into_token_stream(self) -> TokenStream

where Self: Sized,

Equivalent to ToTokens::into_token_stream