[r6rs-discuss] [Formal] Add (sort) and (vector-sort!) procedures

[Marcin 'Qrczak' Kowalczyk]

Eli Barzilay <eli at barzilay.org> writes:

>   (sort file-names
>         (lambda (f1 f2) (< (file-date f1) (file-date f2))))
>
> and
>
>   (map cdr
>        (sort (map (lambda (f) (cons (file-date f) f)) file-names)
>              (lambda (p1) (< (car p1) (car p2)))))
>
> The scond version is doing half the number of FS accesses.

Not half the number but 2*log(N) times less, where N is the number of
elements to be sorted, assuming sorting takes N*log(N) comparisons.

-- 
   __("<         Marcin Kowalczyk
   \__/       qrczak at knm.org.pl
    ^^     http://qrnik.knm.org.pl/~qrczak/