Dukelupus kirjutas isikukoodi valideerimisest .NET'is.
Võrdluseks sama kood kirjutatuna Lispis:
(defun number-to-digits (number)
(map 'list #'digit-char-p (princ-to-string number)))
(defun digits-to-number (digits)
(parse-integer (map 'string #'digit-char digits)))
(defun valid-birth-date (ik-digits)
"Kontrollib kas tegu on korrektse kuupäevaga"
(let ((sajand
(case (first ik-digits)
((1 2) 1800)
((3 4) 1900)
((5 6) 2000))))
(when sajand
(integerp
(ignore-errors
(encode-universal-time
0 0 0
(digits-to-number (subseq ik-digits 5 7))
(digits-to-number (subseq ik-digits 3 5))
(+ sajand (digits-to-number (subseq ik-digits 1 3)))
0))))))
(defun checksum (ik-digits fn)
(mod
(loop for n from 1 to 10
sum (* (1+ (mod (funcall fn n) 9))
(nth (1- n) ik-digits)))
11))
(defun valid-checksum (ik-digits)
(= (first (last ik-digits)) ;; kontrollnumber
(let ((result (checksum ik-digits '1-)))
(if (= 10 result)
(mod (checksum ik-digits '1+) 10)
result))))
(defun valid-isikukood (isikukood)
(let ((ik-digits (number-to-digits isikukood)))
(and
(= (length ik-digits) 11) ;; peab sisaldama 11 numbrit
(valid-birth-date ik-digits)
(valid-checksum ik-digits))))
Tulemused:
CL-USER 57 > (time (valid-isikukood 21107190012))Timing the evaluation of (VALID-ISIKUKOOD 21107190012)
User time = 0.000
System time = 0.000
Elapsed time = 0.000
Allocation = 300 bytes
0 Page faults
T
CL-USER 58 > (time (valid-isikukood "21107190012"))
Timing the evaluation of (VALID-ISIKUKOOD "21107190012")
User time = 0.000
System time = 0.000
Elapsed time = 0.000
Allocation = 288 bytes
0 Page faults
T
CL-USER 59 > (time (valid-isikukood 21107190013))
Timing the evaluation of (VALID-ISIKUKOOD 21107190013)
User time = 0.000
System time = 0.000
Elapsed time = 0.000
Allocation = 300 bytes
0 Page faults
NIL
Huvitav on see, et kui anda isikukood ette stringina siis võtab programm vähem mälu kui numbritega.
Seda koodi saab Lispworksis kasutada ka läbi graafilise liidese:
(capi:prompt-for-integer
"Sisesta isikukood:"
:ok-check 'valid-isikukood)
Tulemusena avaneb selline aken:
Ok-nupp aktiveerub alles siis kui sisestatud on korrektne isikukood.
