You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
80 lines
2.6 KiB
Racket
80 lines
2.6 KiB
Racket
#lang racket/base
|
|
|
|
(require racket/generic
|
|
(prefix-in b: racket/base)
|
|
racket/dict
|
|
racket/class
|
|
racket/match)
|
|
|
|
(provide (all-defined-out))
|
|
|
|
(define-generics indexable
|
|
(ref indexable i)
|
|
(ref-set! indexable i v)
|
|
#:defaults
|
|
([hash? (define ref hash-ref)
|
|
(define ref-set! hash-set!)]
|
|
[object? (define (ref o i) (with-handlers ([exn:fail:object? (λ (exn) (hash-ref (get-field _hash o) i))]) (dynamic-get-field i o)))
|
|
(define (ref-set! o i v) (with-handlers ([exn:fail:object? (λ (exn) (hash-set! (get-field _hash o) i v))]) (dynamic-set-field! i o v)))]))
|
|
|
|
(module+ test
|
|
(require rackunit)
|
|
(define h (make-hash '((foo . 42))))
|
|
(check-equal? (ref h 'foo) 42)
|
|
(ref-set! h 'foo 85)
|
|
(check-equal? (ref h 'foo) 85)
|
|
(ref-set! h 'bar 121)
|
|
(check-equal? (ref h 'bar) 121)
|
|
(define o (make-object (class object% (super-new) (field [_hash (make-hash)][foo 42]))))
|
|
(check-equal? (ref o 'foo) 42)
|
|
(ref-set! o 'foo 100)
|
|
(check-equal? (ref o 'foo) 100)
|
|
(ref-set! o 'bar 121)
|
|
(check-equal? (ref o 'bar) 121))
|
|
|
|
(define (ref* c . is)
|
|
(for/fold ([c c])
|
|
([i (in-list is)])
|
|
(ref c i)))
|
|
|
|
(define (ref*-set! c . is+val)
|
|
(match-define (list is ... i val) is+val)
|
|
(ref-set! (apply ref* c is) i val))
|
|
|
|
(require sugar/debug)
|
|
(define (ref-set*! c . kvs)
|
|
(for ([k (in-list kvs)]
|
|
[v (in-list (cdr kvs))]
|
|
[i (in-naturals)]
|
|
#:when (even? i))
|
|
(ref-set! c k v)))
|
|
|
|
(module+ test
|
|
(define h2 (make-hash (list (cons 'foo (make-hash (list (cons 'bar (make-hash '((zam . 42))))))))))
|
|
(check-equal? (ref* h2 'foo 'bar 'zam) 42)
|
|
(ref*-set! h2 'foo 'bar 'zam 89)
|
|
(check-equal? (ref* h2 'foo 'bar 'zam) 89)
|
|
(ref-set*! h2 'hi 1 'there 2)
|
|
(check-equal? (ref h2 'hi) 1)
|
|
(check-equal? (ref h2 'there) 2))
|
|
|
|
(define-generics countable
|
|
(length countable)
|
|
#:defaults
|
|
([list? (define length b:length)]
|
|
[vector? (define length vector-length)]
|
|
[string? (define length string-length)]
|
|
[bytes? (define length bytes-length)]
|
|
[dict? (define length dict-count)]
|
|
[object? (define (length o) (with-handlers ([exn:fail:object? (λ (exn) 0)]) (b:length (get-field _list o))))]))
|
|
|
|
(module+ test
|
|
(require racket/list)
|
|
(check-equal? (length (make-list 42 #f)) 42)
|
|
(check-equal? (length (make-vector 42 #f)) 42)
|
|
(check-equal? (length (make-string 42 #\x)) 42)
|
|
(check-equal? (length (make-bytes 42 0)) 42)
|
|
(check-equal? (length (map cons (range 42) (range 42))) 42)
|
|
(check-equal? (length (make-object (class object% (super-new) (field [_list (make-list 42 #f)])))) 42)
|
|
(check-equal? (length (make-object (class object% (super-new)))) 0))
|