diff options
Diffstat (limited to 'racket.html.markdown')
-rw-r--r-- | racket.html.markdown | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/racket.html.markdown b/racket.html.markdown index fa20bf67..3a1cdd29 100644 --- a/racket.html.markdown +++ b/racket.html.markdown @@ -102,8 +102,8 @@ some-var ; => 5 ;; Local binding: me is bound to "Bob" only within (let ...) (let ([me "Bob"]) - "Alice" - me) ; => "Bob" + "Alice" + me) ; => "Bob" ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; 3. Structs and Collections @@ -250,20 +250,20 @@ m ; => '#hash((b . 2) (a . 1) (c . 3)) (if #t ; test expression "this is true" ; then expression - "this is false" ; else expression - ) ; => "this is true" + "this is false") ; else expression +; => "this is true" ;; In conditionals, all non-#f values are treated as true (member "Groucho" '("Harpo" "Groucho" "Zeppo")) ; => '("Groucho" "Zeppo") (if (member "Groucho" '("Harpo" "Groucho" "Zeppo")) - 'yep - 'nope) ; => 'yep + 'yep + 'nope) +; => 'yep ;; "cond" chains a series of tests to select a result -(cond - [(> 2 2) (error "wrong!")] - [(< 2 2) (error "wrong again!")] - [else 'ok]) ; => 'ok +(cond [(> 2 2) (error "wrong!")] + [(< 2 2) (error "wrong again!")] + [else 'ok]) ; => 'ok ;;; Pattern Matching @@ -296,13 +296,13 @@ m ; => '#hash((b . 2) (a . 1) (c . 3)) ;;; Comprehensions (for/list ([i '(1 2 3)]) - (add1 i)) ; => '(2 3 4) + (add1 i)) ; => '(2 3 4) (for/list ([i '(1 2 3)] #:when (even? i)) - i) ; => '(2) + i) ; => '(2) (for/hash ([i '(1 2 3)]) - (values i (number->string i))) ; => '#hash((1 . "1") (2 . "2") (3 . "3")) + (values i (number->string i))) ; => '#hash((1 . "1") (2 . "2") (3 . "3")) ;; To combine iteration results, use "for/fold" (for/fold ([sum 0]) ([i '(1 2 3 4)]) @@ -448,7 +448,7 @@ vec ; => #(1 2 3 4) (define amount 0) (define (deposit a) (set! amount (+ amount a))) (define (balance) amount) -) + ) (require 'bank-account) (deposit 5) |