On Jul 12, 2014, at 12:53 PM, Brian Adkins wrote: > I'm porting more Haskell code to Racket as a learning exercise. When I got to > this line: > > isPos (r,c) = elem r [0..4] && elem c [0..r] > > I first wrote this: > > (define (is-pos r c) (and (member r (lgen 0 4)) > (member c (lgen 0 r)))) > > where lgen is: > > (define (lgen m n) (build-list (+ 1 (- n m)) (λ (x) (+ x m)))) >
Have you considered turning your Haskell code into prefix and leaving it otherwise alone (mostly): #lang racket ;; ----------------------------------------------------------------------------- ;; prelude (module+ test (require rackunit)) (define-syntax-rule (= (f x ...) expression) (define (f x ...) expression)) (define (.. low high) (range low high)) (define (elem r rng) (cons? (member r rng))) ;; ----------------------------------------------------------------------------- ;; Haskell to Racket ;; isPos (r,c) = elem r [0..4] && elem c [0..r] ((isPos r c) . = . (and (elem r [.. 0 4]) (elem c [.. 0 r]))) ;; ----------------------------------------------------------------------------- ;; some tests (module+ test (check-true (isPos 1 0)) (check-true (isPos 2 1)) (check-false (isPos 1 2)) (check-false (isPos 5 1))) Okay, the line is still a bit wider but that's because of extra spaces -- Matthias ____________________ Racket Users list: http://lists.racket-lang.org/users
