'(("!" ssl ssl open-ssl-stream)
("!!" starttls starttls starttls-open-stream)
("!socks" socks socks socks-open-network-stream)
- ("!direct" direct direct open-network-stream))
+ ("!direct" direct nil open-network-stream))
"An alist of (SPEC-STRING SYMBOL FEATURE OPEN-STREAM-FUNCTION).
SPEC-STRING is a string for stream-type spec (it must start with '!').
SYMBOL is a symbol which indicates the name of the stream type.