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22.4.17 *print-base*, *print-radix* [Variable]

Value Type::

*print-base*—a radix. *print-radix*—a generalized boolean.

Initial Value::

The initial value of *print-base* is 10. The initial value of *print-radix* is false.

Description::

*print-base* and *print-radix* control the printing of rationals. The value of *print-base* is called the current output base .

The value of *print-base* is the radix in which the printer will print rationals. For radices above 10, letters of the alphabet are used to represent digits above 9.

If the value of *print-radix* is true, the printer will print a radix specifier to indicate the radix in which it is printing a rational number. The radix specifier is always printed using lowercase letters. If *print-base* is 2, 8, or 16, then the radix specifier used is #b, #o, or #x, respectively. For integers, base ten is indicated by a trailing decimal point instead of a leading radix specifier; for ratios, #10r is used.

Examples::
      (let ((*print-base* 24.) (*print-radix* t))
        (print 23.))
      |>  #24rN
     =>  23
      (setq *print-base* 10) =>  10
      (setq *print-radix* nil) =>  NIL
      (dotimes (i 35)
         (let ((*print-base* (+ i 2)))           ;print the decimal number 40
           (write 40)                            ;in each base from 2 to 36
           (if (zerop (mod i 10)) (terpri) (format t " "))))
      |>  101000
      |>  1111 220 130 104 55 50 44 40 37 34
      |>  31 2C 2A 28 26 24 22 20 1J 1I
      |>  1H 1G 1F 1E 1D 1C 1B 1A 19 18
      |>  17 16 15 14
     =>  NIL
      (dolist (pb '(2 3 8 10 16))
         (let ((*print-radix* t)                 ;print the integer 10 and
               (*print-base* pb))                ;the ratio 1/10 in bases 2,
          (format t "~&~S  ~S~
      |>  #b1010  #b1/1010
      |>  #3r101  #3r1/101
      |>  #o12  #o1/12
      |>  10.  #10r1/10
      |>  #xA  #x1/A
     =>  NIL
Affected By::

Might be bound by format, and write, write-to-string.

See Also::

format , write , write-to-string