diff options
Diffstat (limited to 'src/utils.rs')
| -rw-r--r-- | src/utils.rs | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/src/utils.rs b/src/utils.rs index 3fa07e7..27373ef 100644 --- a/src/utils.rs +++ b/src/utils.rs @@ -15,12 +15,18 @@ use syn::{ pub(crate) type Variants = Punctuated<Variant, Token![,]>; -macro_rules! error { - ($span:expr, $msg:expr) => { - syn::Error::new_spanned(&$span, $msg) +macro_rules! format_err { + ($span:expr, $msg:expr $(,)?) => { + syn::Error::new_spanned(&$span as &dyn quote::ToTokens, &$msg as &dyn std::fmt::Display) }; ($span:expr, $($tt:tt)*) => { - error!($span, format!($($tt)*)) + format_err!($span, format!($($tt)*)) + }; +} + +macro_rules! bail { + ($($tt:tt)*) => { + return Err(format_err!($($tt)*)) }; } @@ -98,7 +104,11 @@ pub(crate) fn determine_visibility(vis: &Visibility) -> Visibility { /// This is almost equivalent to `syn::parse2::<Nothing>()`, but produces /// a better error message and does not require ownership of `tokens`. pub(crate) fn parse_as_empty(tokens: &TokenStream) -> Result<()> { - if tokens.is_empty() { Ok(()) } else { Err(error!(tokens, "unexpected token: {}", tokens)) } + if tokens.is_empty() { + Ok(()) + } else { + bail!(tokens, "unexpected token: `{}`", tokens) + } } pub(crate) fn respan<T>(node: &T, span: Span) -> T @@ -131,14 +141,14 @@ pub(crate) trait SliceExt { impl SliceExt for [Attribute] { /// # Errors /// - /// * There are multiple specified attributes. - /// * The `Attribute::tokens` field of the specified attribute is not empty. + /// - There are multiple specified attributes. + /// - The `Attribute::tokens` field of the specified attribute is not empty. fn position_exact(&self, ident: &str) -> Result<Option<usize>> { self.iter() .try_fold((0, None), |(i, mut prev), attr| { if attr.path.is_ident(ident) { if prev.replace(i).is_some() { - return Err(error!(attr, "duplicate #[{}] attribute", ident)); + bail!(attr, "duplicate #[{}] attribute", ident); } parse_as_empty(&attr.tokens)?; } |