On 10060 day of my life vseguip@gmail.com wrote:
I did some profiling...
My profiling shows that on SBCL most "slowness" comes from flexi-streams. For example, such low-level method as flexi-streams::unread-char% calls flexi-streams:translate-char that uses with-output-to-sequence. And last macro generates code that create new instance of flexi-stream, and making instances conses very much on SBCL. You may blame either SBCL or flexi-streams (I tend to blame flexi-streams).
unread-char (and unread-char%) is called by chunga quite often.