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Function DIGIT-CHAR-P

Syntax

  • digit-char-p char &optional radixweight

Arguments and Values

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.)

Exceptional Situations

None.

Editor Notes

The output of digit-char-p might be confusing, as this function's return value also serves a different purpose. digit-char-p, aside from being a predicate, is also a converting function: it converts a digit in a given radix to its corresponding integer value.

See Also

Notes

Digits are graphic characters.