ISBN13 check digit: Difference between revisions
Add Miranda
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978-1788399081 good
978-1788399083 bad</pre>
=={{header|Miranda}}==
<syntaxhighlight lang="miranda">main :: [sys_message]
main = [Stdout (lay (map test tests))]
test :: [char]->[char]
test isbn = isbn ++ ": good", if isbn13 isbn
= isbn ++ ": bad", otherwise
tests :: [[char]]
tests = ["978-0596528126",
"978-0596528120",
"978-1788399081",
"978-1788399083"]
isbn13 :: [char]->bool
isbn13 str = False, if #isbn ~= 13 \/ ~and (map digit isbn)
= check mod 10 = 0, otherwise
where isbn = filter (~= '-') str
digits = map (numval.(:[])) isbn
check = sum (zipwith (*) digits (concat (repeat [1,3])))
uncurry :: (*->**->***)->(*,**)->***
uncurry f (a,b) = f a b
zipwith :: (*->**->***)->[*]->[**]->[***]
zipwith f a b = map (uncurry f) (zip2 a b)</syntaxhighlight>
{{out}}
<pre>978-0596528126: good
978-0596528120: bad
978-1788399081: good
978-1788399083: bad</pre>
=={{header|Modula-2}}==
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