Small example:

compiler errors

task <unnamed> failed at 'assertion failed: rp.is_none()', /private/tmp/rust-h4RT/rust-0.8/src/librustc/middle/typeck/collect.rs:1108
error: internal compiler error: unexpected failure
note: the compiler hit an unexpected failure path. this is a bug
note: try running with RUST_LOG=rustc=1 to get further details and report the results to github.com/mozilla/rust/issues
task <unnamed> failed at 'explicit failure', /private/tmp/rust-h4RT/rust-0.8/src/librustc/rustc.rs:391

file.rs

mod parser {
    // type Parser a = String -> [(a, String)]
    type Parser<'self, T> = &'self fn(&str) -> ~[(T, &str)];

    pub fn result<T>( p : T ) -> Parser<'self, T> {
        return |s| ~[(p, s)]
    }
}