| 1 | (import scheme chicken) |
|---|
| 2 | |
|---|
| 3 | (define assq-val-no-warning (lambda (sym lst) |
|---|
| 4 | (let ((el (assq sym lst))) |
|---|
| 5 | (if (list? el) |
|---|
| 6 | (if (fx< 1 (length el)) |
|---|
| 7 | (cadr el) |
|---|
| 8 | #f) |
|---|
| 9 | (if (pair? el) |
|---|
| 10 | (cdr el) |
|---|
| 11 | #f))))) |
|---|
| 12 | |
|---|
| 13 | |
|---|
| 14 | (define assq-val-warning (lambda (sym lst) |
|---|
| 15 | (let ((el (assq sym lst))) |
|---|
| 16 | (if (pair? el) |
|---|
| 17 | (if (list? el) |
|---|
| 18 | (if (fx< 1 (length el)) |
|---|
| 19 | (cadr el) |
|---|
| 20 | #f) |
|---|
| 21 | (cdr el)) ; <== compiler warning |
|---|
| 22 | #f)))) |
|---|
| 23 | |
|---|
| 24 | (define assq-val-also-no-warning (lambda (sym lst) |
|---|
| 25 | (define el (assq sym lst)) |
|---|
| 26 | (if (pair? el) |
|---|
| 27 | (if (list? el) |
|---|
| 28 | (if (fx< 1 (length el)) |
|---|
| 29 | (cadr el) |
|---|
| 30 | #f) |
|---|
| 31 | (cdr el)) |
|---|
| 32 | #f))) |
|---|
| 33 | |
|---|
| 34 | (print (assq-val-no-warning 'a '((a "a")))) ; => "a" |
|---|
| 35 | (print (assq-val-no-warning 'a '((a . "a")))) ; => "a" |
|---|
| 36 | (print (assq-val-no-warning 'b '((a . "a")))) ; => #f |
|---|
| 37 | |
|---|
| 38 | (print (assq-val-warning 'a '((a "a")))) ; => "a" |
|---|
| 39 | (print (assq-val-warning 'a '((a . "a")))) ; => "a" |
|---|
| 40 | (print (assq-val-warning 'b '((a . "a")))) ; => #f |
|---|
| 41 | |
|---|
| 42 | (print (assq-val-also-no-warning 'a '((a "a")))) ; => "a" |
|---|
| 43 | (print (assq-val-also-no-warning 'a '((a . "a")))) ; => "a" |
|---|
| 44 | (print (assq-val-also-no-warning 'b '((a . "a")))) ; => #f |
|---|
