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digit-char Characters Dictionary graphic-char-p
Function

digit-char-p

digit-char-p char &optional radix ⇒ weight

Arguments and Values

chara character.
radixa radix. The default is 10.
weighteither a non-negative integer less than radix, or false.

Description

Tests whether char is a digit in the specified radix (i.e., with a weight less than radix). If it is a digit in that radix, its weight is returned as an integer; otherwise nil is returned.

Examples

 (digit-char-p #\5)    ⇒  5
 (digit-char-p #\5 2)  ⇒  false
 (digit-char-p #\A)    ⇒  false
 (digit-char-p #\a)    ⇒  false
 (digit-char-p #\A 11) ⇒  10
 (digit-char-p #\a 11) ⇒  10
 (mapcar #'(lambda (radix) 
             (map 'list #'(lambda (x) (digit-char-p x radix)) 
                  "059AaFGZ"))
         '(2 8 10 16 36))
 ⇒  ((0 NIL NIL NIL NIL NIL NIL NIL)
     (0 5 NIL NIL NIL NIL NIL NIL)
     (0 5 9 NIL NIL NIL NIL NIL)
     (0 5 9 10 10 15 NIL NIL)
     (0 5 9 10 10 15 16 35))

Affected By

None. (In particular, the results of this predicate are independent of any special syntax which might have been enabled in the current readtable.)

See Also

alphanumericp

Notes

Digits are graphic characters.

Backlinks

alphanumericp, Characters Dictionary, digit-char, Introduction to Characters, Symbols in the COMMON-LISP Package