diff options
| -rw-r--r-- | racket.html.markdown | 27 |
1 files changed, 14 insertions, 13 deletions
diff --git a/racket.html.markdown b/racket.html.markdown index 60a895e0..6c40c3c8 100644 --- a/racket.html.markdown +++ b/racket.html.markdown @@ -117,16 +117,16 @@ some-var ; => 5 ;; let* is like let, but allows you to use previous bindings in creating later bindings (let* ([x 1] [y (+ x 1)]) - (* x y)) + (* x y)) ;; finally, letrec allows you to define recursive and mutually recursive functions (letrec ([is-even? (lambda (n) - (or (zero? n) - (is-odd? (sub1 n))))] - [is-odd? (lambda (n) - (and (not (zero? n)) - (is-even? (sub1 n))))]) - (is-odd? 11)) + (or (zero? n) + (is-odd? (sub1 n))))] + [is-odd? (lambda (n) + (and (not (zero? n)) + (is-even? (sub1 n))))]) + (is-odd? 11)) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; 3. Structs and Collections @@ -413,7 +413,7 @@ m ; => '#hash((b . 2) (a . 1) (c . 3)) <-- no `d' (loop 5) ; => i=5, i=6, ... ;; Similarly, with a named let -(let loop ((i 0)) +(let loop ([i 0]) (when (< i 10) (printf "i=~a\n" i) (loop (add1 i)))) ; => i=0, i=1, ... @@ -441,17 +441,19 @@ m ; => '#hash((b . 2) (a . 1) (c . 3)) <-- no `d' (for ([i (in-set (set 'x 'y 'z))]) (displayln i)) -(for ([(k v) (in-hash (hash 'a 1 'b 2 'c 3 ))]) +(for ([(k v) (in-hash (hash 'a 1 'b 2 'c 3))]) (printf "key:~a value:~a\n" k v)) ;;; More Complex Iterations ;; Parallel scan of multiple sequences (stops on shortest) -(for ([i 10] [j '(x y z)]) (printf "~a:~a\n" i j)) +(for ([i 10] [j '(x y z)]) + (printf "~a:~a\n" i j)) ; => 0:x 1:y 2:z ;; Nested loops -(for* ([i 2] [j '(x y z)]) (printf "~a:~a\n" i j)) +(for* ([i 2] [j '(x y z)]) + (printf "~a:~a\n" i j)) ; => 0:x, 0:y, 0:z, 1:x, 1:y, 1:z ;; Conditions @@ -663,8 +665,7 @@ vec ; => #(1 2 3 4) (define amount 0) (define (deposit a) (set! amount (+ amount a))) - (define (balance) amount) - ) + (define (balance) amount)) (require 'bank-account) (deposit 5) |