[Larceny-users] Performance of List Based Data Structures With ERR5RS Recorcs

[Ray Racine]

Naively I did not expect this result in the sense of O(1) for vector-like
vs. O(n) of cons lists.
Records are almost 10x slower then cons lists.

(import (rnrs))
(import (err5rs records syntactic))
(import (primitives time))

(define-record-type rec
  #t #t a b c d e)

'records

(time
 (let ((r (make-rec 'a 'b 'c 'd 'e)))
   (do ((i 10000000 (fx- i 1)))
       ((fxzero? i) (rec-e r))
     (rec-a r)
     (rec-b r)
     (rec-c r)
     (rec-d r)
     (rec-e r))))

'lists

(time
 (let ((data '(a b c d e)))
   (do ((i 10000000 (fx- i 1)))
       ((fxzero? i) (cadr (cdddr data)))
     (car data)
     (cadr data)
     (caddr data)
     (cadddr data)
     (cadr (cdddr data)))))


> records

> Words allocated: 0
Words reclaimed: 0
Elapsed time...: 1126 ms (User: 1126 ms; System: 0 ms)
Elapsed GC time: 0 ms (CPU: 0 in 0 collections.)
e

> lists

> Words allocated: 0
Words reclaimed: 0
Elapsed time...: 129 ms (User: 129 ms; System: 0 ms)
Elapsed GC time: 0 ms (CPU: 0 in 0 collections.)
e

>

Ray
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