Say stuff with a template that has variables inside. It's like cowsay. Plus it's a macro, which is neat.
(with-output-to-string (bag) (blah bag "Hi {{person}}!" :person "Joe")); => "Hi Joe!"
(blah t "Hi {{person}}! I am {{computer-assistant}}, here to help you, {{person}}, with all of your problems."
:person "Fred"
:computer-assistant "Eliza")
; => Hi Fred! I am Eliza, here to help you, Fred, with all of your problems.(blaher "Hi {{person}}! I am {{computer-assistant}}, here to help you, {{person}}, with all of your problems.")macro expands to:
(LAMBDA (#:STREAM.6790 &KEY ((:COMPUTER-ASSISTANT #:G6791))
((:PERSON #:G6792)))
(PRINC "Hi " #:STREAM.6790)
(PRINC #:G6792 #:STREAM.6790)
(PRINC "! I am " #:STREAM.6790)
(PRINC #:G6791 #:STREAM.6790)
(PRINC ", here to help you, " #:STREAM.6790)
(PRINC #:G6792 #:STREAM.6790)
(PRINC ", with all of your problems." #:STREAM.6790))