RosettaCodeData/Task/CUSIP/Factor/cusip.factor

19 lines
585 B
Factor

USING: combinators.short-circuit formatting kernel math
math.parser qw regexp sequences unicode ;
IN: rosetta-code.cusip
: cusip-check-digit ( seq -- n )
but-last-slice [
[ dup alpha? [ digit> ] [ "*@#" index 36 + ] if ] dip
odd? [ 2 * ] when 10 /mod +
] map-index sum 10 mod 10 swap - 10 mod ;
: cusip? ( seq -- ? )
{
[ R/ [0-9A-Z*@#]+/ matches? ]
[ [ last digit> ] [ cusip-check-digit ] bi = ]
} 1&& ;
qw{ 037833100 17275R102 38259P508 594918104 68389X106 68389X105 }
[ dup cusip? "correct" "incorrect" ? "%s -> %s\n" printf ] each