ANSI Common Lisp   22 Printer   22.3 Formatted Output   22.3.2 FORMAT Radix Control

22.3.2.1 Tilde R: Radix

~nR prints arg in radix n. The modifier flags and any remaining parameters are used as for the ~D directive. ~D is the same as ~10R. The full form is ~radix,mincol,padchar,commachar,comma-intervalR.

If no prefix parameters are given to ~R, then a different interpretation is given. The argument should be an integer. For example, if arg is 4:

• ~R prints arg as a cardinal English number: four.

• ~:R prints arg as an ordinal English number: fourth.

• ~@R prints arg as a Roman numeral: IV.

• ~:@R prints arg as an old Roman numeral: IIII.

For example:

 (format nil "~,,' ,4:B" 13)  "1101"
 (format nil "~,,' ,4:B" 17)  "1 0001"
 (format nil "~19,0,' ,4:B" 3333)  "0000 1101 0000 0101"
 (format nil "~3,,,' ,2:R" 17)  "1 22"
 (format nil "~,,'|,2:D" #xFFFF)   "6|55|35"

If and only if the first parameter, n, is supplied, ~R binds *print-escape* to false, *print-radix* to false, *print-base* to n, and *print-readably* to false.

If and only if no parameters are supplied, ~R binds *print-base* to 10.