The #48in24 Challenge
exercism.org
Try out a new programming challenge each week. Broaden your horizons and level up your programming skills as your explore the varied paradigms and ideas that different languages embrace. It's free, fun, and useful!

Just because Exercism doesn’t offer your favorite language as an official track, it doesn’t mean we can’t play at all. Post some solutions to the weekly challenges in the language of your choice!

  • AndyOPM
    1·
    8 months ago
    Luhn 
    USING: combinators.short-circuit.smart kernel math math.functions math.parser sequences sequences.extras sets unicode ;

: luhn? ( str -- ? )
  " " without
  dup { [ length 2 < ] [ [ digit? ] all? not ] } || [ drop f ] [
    string>digits
    reverse [ <evens> sum ] [ <odds> ] bi
    [ 2 * dup 9 > [ 9 - ] when ] map-sum +
    10 divisor?
  ] if
;
    • AndyOPM
      1·
      8 months ago
      Luhn, again 
      USING: combinators.short-circuit.smart kernel math math.parser rosetta-code.luhn-test sequences sets unicode ;

: ex-luhn? ( str -- ? )
  " " without
  dup {
    [ length 2 < ]
    [ [ digit? ] all? not ]
  } || [ drop f ] [
    string>number luhn?
  ] if
;
      Luhn, a third time 
      USING: combinators.short-circuit.smart kernel math sequences sets unicode validators ;

: ex-luhn? ( str -- ? )
  " " without
  dup {
    [ length 2 < ]
    [ [ digit? ] all? not ]
  } || [ drop f ] [ luhn? ] if
;