/// If a function is only used once, we can place it where it's used,
/// instead of making a separate definition for it.  This does *not*
/// define a variable named `callback`; the name is visible only to the
/// the human reader, not the compiler.
function request() {
    $.get('request', function callback(x) {
        log('received "' + x + '"');
    });
}

request();