; define constants for some non-printable ASCII chars
; (in case #\ equivalents are not available)
; and some sequences of such chars
(defconstant $/nul (code-char 0) "<NUL> like #\nul")
(defconstant $/us (code-char 31) "<US> like #\us")
(defconstant $/nul-us (list $/nul $/us) "<NUL><US> like #\nul #\us")
;example use of the defined constants
;instead of the explicit non-printable chars
(print $/nul-us)
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