Macro tectonic_errors::atry

macro_rules! atry {
    (@aa $ar:ident [ $($inner:tt)+ ] ) => { ... };
    (@aa $ar:ident ( note $($inner:tt)+ ) ) => { ... };
    ($op:expr ; $( $annotation:tt )+) => { ... };
}

“Annotated try” — like try!, but with the ability to add extended context to the error message. This tries to provide a bit more syntactic sugar than anyhow’s with_context(), and it supports our AnnotatedMessage context type.

Example

let ok_val = atry!(
    my_fallible_operation(arg, option);
    ["the operation on `{}` failed", arg]
    (note "option was `{}`; maybe you should choose a better value next time", option)
);

This is equivalent to let ok_val = my_fallible_operation(arg)?;, but if the operation fails, the returned error will have a message formatted as per the format expression in square brackets, with attached “note” text formatted as per the parenthesized note expression. There may be zero, one, or many notes attached.