From: matz@... (Yukihiro Matsumoto)
Date: 2000-09-29T08:46:17+09:00
Subject: [ruby-talk:5179] Re: methods w/ ! giving nil

Hi,

In message "[ruby-talk:5173] Re: methods w/ ! giving nil"
    on 00/09/28, Davide Marchignoli <marchign@di.unipi.it> writes:
|
|> Actually Ruby does have its own qsort routine in C (in util.c), which
|> is compatible with original qsort(3).  Only problem left is re-design
|> and hack the routine.   I'm afraid it's a tough task, for me at least.
|
|Changing swap does not work since swap can be invoked also for equal
|values and it one has to be careful in defining if the list is changed or
|not. The only other solution (I can think of) is checking if the array is
|already sorted. The check is already present in the ruby_sort code so this
|small change does not affect performances.
|
|In any case, the *average* cost of checking if an array is sorted is a
|*small* constant number of comparisons.
|
|The following patch should do the job:

Let me compare this with [ruby-talk:4564].  And could give me a patch
in unified diff style next time?

							matz.