pub fn input(f: &fn(&str) -> bool) -> bool
Iterate directly over the command line arguments (no arguments implies
reading from stdin).
Fails when attempting to read from a file that can't be opened.
Prefix searches with a type followed by a colon (e.g.
fn:) to restrict the search to a given type.
Accepted types are: fn, mod,
struct (or str), enum,
trait, typedef (or
tdef).