detect-chord.egi

(define $roots {| [0 "C"] [1 "C#"] [2 "D"] [3 "D#"] [4 "E"] [5 "F"] [6 "F#"] [7 "G"] [8 "G#"] [9 "A"] [10 "A#"] [11 "B"] |})

(define $detect-root
  (lambda [$notes]
    roots_(modulo (car (sort notes)) 12)))

(define $detect-chord
  (lambda [$notes]
    (match (sort notes) (multiset integer)
      {[<cons $n <cons ,(+ n 4) <cons ,(+ n 7) <nil>>>> "Major"]
       [<cons $n <cons ,(+ n 3) <cons ,(+ n 7) <nil>>>> "Minor"]
       [<cons $n <cons ,(+ n 5) <cons ,(+ n 7) <nil>>>> "Sus4"]
       [<cons $n <cons ,(+ n 3) <cons ,(+ n 6) <nil>>>> "Dim"]
       [<cons $n <cons ,(+ n 4) <cons ,(+ n 7) <cons ,(+ n 10) <nil>>>>> "7"]
       [<cons $n <cons ,(+ n 4) <cons ,(+ n 7) <cons ,(+ n 11) <nil>>>>> "Major7"]
       [<cons $n <cons ,(+ n 3) <cons ,(+ n 7) <cons ,(+ n 10) <nil>>>>> "Minor7"]
       [_ "unknown"]})))

(define $main
  (lambda [$args]
    (let {[$num-args (map read args)]}
      (print 
        (S.concat {(detect-root num-args) " " (detect-chord num-args)})))))