6 releases
0.1.5 | Mar 10, 2019 |
---|---|
0.1.4 | Mar 9, 2019 |
#784 in Debugging
80 downloads per month
11KB
70 lines
slog_unwraps
Syntactic sugar to slog an error before unwrapping. It will add caller file and line information to the log statement so you don't have to turn on RUST_BACKTRACE to see what went wrong, but know that that only makes sense in debug mode. In release mode this information will either be missing or unreliable.
At first I had an expects
function as well to be able to add context, but I really think you should use the
failure
crate, which provides a context
method on errors, and it's much cleaner, so expects
no longer exists. If you don't want to use failure
, you will have to make sure your errors display sensible messages.
Example
run with cargo run --example basic
use
{
std :: { fs::File } ,
slog :: { Drain, Level, Logger, o, crit } ,
slog_term :: { FullFormat, PlainSyncDecorator } ,
slog_unwraps :: { ResultExt } ,
};
fn main()
{
let plain = PlainSyncDecorator::new( std::io::stderr() ) ;
let log = Logger::root( FullFormat::new( plain ).build().fuse(), o!() ) ;
// This will output (in one line, wrapped here for readablility):
//
// Mar 08 18:13:52.034 CRIT PANIC - fn `main` calls `unwraps` @ examples/basic.rs:20
// -> Error: No such file or directory (os error 2)
//
// and then will call unwrap for you
//
let f = File::open( "dont.exist" );
let _file = f.unwraps( &log );
// This is equivalent. Of course you can do something else with the result after logging
// rather than unwrapping. This only logs if the result is an error.
//
let g = File::open( "dont.exist" );
let _file = g.log( &log, Level::Critical ).unwrap();
// Without this crate, everytime you want to unwrap, you would write something like:
//
let h = File::open( "dont.exist" );
let _file = match h
{
Ok ( f ) => f,
Err( e ) => { crit!( log, "{}", e ); panic!() }
};
}
License: Unlicense
Dependencies
~5–7MB
~129K SLoC