2 releases
0.1.1 | Mar 13, 2023 |
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0.1.0 | Mar 13, 2023 |
#2197 in Procedural macros
53 downloads per month
Used in 3 crates
(via bevy_proto_derive)
9KB
65 lines
optional-error
This crate provides a simpler way to create and manage an Option<syn::Error>
.
fn parse(input: DeriveInput) -> Result<TokenStream, syn::Error> {
// Create an optional error to contain zero or more errors
let mut errors = OptionalError::default();
if !matches!(input.vis, Visibility::Public(_)) {
// Combine with a new error (or initialize if empty)
errors.combine(syn::Error::new(Span::call_site(), "input must be marked `pub`"));
}
match input.data {
syn::Data::Struct(_) | syn::Data::Enum(_) => { /* ... */ }
syn::Data::Union(_) => {
// Combine some more!
errors.combine(syn::Error::new(Span::call_site(), "unions not supported"));
}
}
// Easy early return with all errors (if any)
errors.try_throw()?;
// ...
}
Dependencies
~1.5MB
~35K SLoC