Crate slog_scope [−] [src]

Logging scopes for slog-rs

Logging scopes are convinience functionality for slog-rs to free user from manually passing Logger objects around.

Set of macros is also provided as an alternative to original slog crate macros, for logging directly to Logger of the current logging scope.

Note: Part of a slog logging philosophy is ability to freely express logging contexts according to logical structure, rather than code structure. By using logging scopes the logging context is tied to code flow again, which is less expressive.

It is generally advised NOT to use slog_scope in libraries. Read more in slog-rs FAQ

#[macro_use(o, slog_info, slog_log, slog_record, slog_record_static, slog_b)]
extern crate slog;
#[macro_use]
extern crate slog_scope;
extern crate slog_term;

use slog::Drain;

fn foo() {
    slog_info!(slog_scope::logger(), "foo");
    info!("foo"); // Same as above, but more ergonomic.
}

fn main() {
    let plain = slog_term::PlainSyncDecorator::new(std::io::stdout());
    let log = slog::Logger::root(
        slog_term::FullFormat::new(plain)
        .build().fuse(), o!()
    );

    slog_scope::set_global_logger(log);
    slog_scope::scope(slog_scope::logger().new(o!("scope" => "1")),
        || foo()
    );
}