RosettaCodeData/Task/ISBN13-check-digit/AppleScript/isbn13-check-digit-2.applescript
2024-03-06 22:25:12 -08:00

38 lines
1.3 KiB
AppleScript

on validateISBN13(ISBN13)
if (ISBN13's class is not text) then return false
set astid to AppleScript's text item delimiters
set AppleScript's text item delimiters to {"-", space}
set ISBN13 to ISBN13's text items
set AppleScript's text item delimiters to ""
set ISBN13 to ISBN13 as text
set AppleScript's text item delimiters to astid
if (((count ISBN13) is not 13) or (ISBN13 contains ".") or (ISBN13 contains ",")) then return false
try
ISBN13 as number
on error
return false
end try
set sum to 0
repeat with i from 1 to 12 by 2
set sum to sum + (character i of ISBN13) + (character (i + 1) of ISBN13) * 3 -- Automatic text-to-number coercions.
end repeat
return ((sum + (character 13 of ISBN13)) mod 10 = 0)
end validateISBN13
-- Test:
set output to {}
set verdicts to {"bad", "good"}
repeat with thisISBN13 in {"978-0596528126", "978-0596528120", "978-1788399081", "978-1788399083"}
set isValid to validateISBN13(thisISBN13)
set end of output to thisISBN13 & ": " & item ((isValid as integer) + 1) of verdicts
end repeat
set astid to AppleScript's text item delimiters
set AppleScript's text item delimiters to linefeed
set output to output as text
set AppleScript's text item delimiters to astid
return output