Macro return_error 

macro_rules! return_error {
    ($diagnostic:expr) => { ... };
    ($diagnostic:expr, $fragment:expr) => { ... };
}

Macro to return an error from a diagnostic function call

Usage:

• return_error!(diagnostic_function(args)) - Returns an error without fragment
• return_error!(diagnostic_function(args), fragment) - Returns an error with fragment

Expands to: return Err(Error(diagnostic_function(args))) or return Err(Error(diagnostic_function(args).with_fragment(fragment)))

Examples:

• return_error!(sequence_exhausted(Type::Uint8))
• return_error!(sequence_exhausted(Type::Uint8), fragment)