Enum ParseError 

pub enum ParseError {
    RustcWillCatch {
        reason: &'static str,
    },
    FacetError {
        message: String,
        span: Span,
    },
}

Errors that can occur during parsing of derive macro attributes.

Some errors are caught by rustc itself, so we don’t emit duplicate diagnostics. Others are facet-specific and need our own compile_error!.

Variants

RustcWillCatch

An error that rustc will catch on its own - we don’t emit a diagnostic.

We track these so the code is explicit about why we’re not panicking, and to document what rustc catches.

Fields

reason: &'static str

Description of what rustc will catch (for documentation purposes)

FacetError

A facet-specific error that rustc won’t catch - we emit compile_error!

Fields

message: String

The error message to display

span: Span

The span to point the error at

Implementations

impl ParseError

pub fn rustc_will_catch(reason: &'static str) -> Self

Create a “rustc will catch this” error.

Use this when we detect an error that rustc will also catch, so we avoid duplicate diagnostics.

pub fn facet_error(message: impl Into<String>, span: Span) -> Self

Create a facet-specific error with a span.

pub fn to_compile_error(&self) -> Option<TokenStream>

Convert to a compile_error! TokenStream, or None if rustc will catch it.

Trait Implementations

impl Debug for ParseError

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

Formats the value using the given formatter.