From: Logan Capaldo <logancapaldo@...>
Date: 2005-12-07T14:00:02+09:00
Subject: Re: Good Ruby Examples?


On Dec 6, 2005, at 12:47 PM, gabriele renzi wrote:

> Wayne Vucenic ha scritto:
>> Hi Hampton,
>>> What I'm asking you guys for is if you have any short code ideas  
>>> that
>>> can be programmed *really* quickly in Ruby that might illustrate its
>>> versatility. Some code example that would be hell to write in other
>>> languages that would be interesting for an hour long explaination.
>> My favorite is the well-known quicksort algorithm:
>> def quicksort(a)
>>   return a if a.size <= 1
>>   pivot = a[0]
>>   quicksort(a.select {|i| i < pivot }) +
>>             a.select {|i| i == pivot } +
>>   quicksort(a.select {|i| i > pivot })
>> end
>> quicksort is "hell" to write in C or C++ unless you're extremely  
>> clever.
>
> you may appreciate Enumerable#partition:
> def qs(a)
>   return a if a.size <=1
>   pivot = a.shift
>   less, more = a.partition{|y| y < pivot}
>   qs(less) + [pivot] + qs(more)
> end
>
>
>

I don't know, if you start throwing partition in there, you're this  
close to just saying a.sort