Converting Char to Integer in Common Lisp

Question

What is the proper way to convert the character #\1 to the integer 1? I coerced a number into a list and got this: (#\1 #\2 #\3)

and want to convert that into

(1 2 3)

Answer 1

CL-USER > (digit-char-p #\1)
1

digit-char-p returns

• the numeric value of the character, if it is a digit char
• NIL otherwise

Thus it is both:

• a predicate, since numbers are true
• a conversion function