From: James Edward Gray II <james@...>
Date: 2005-10-28T00:55:04+09:00
Subject: Re: [SUMMARY] Ducksay (#52)

On Oct 27, 2005, at 10:48 AM, Pit Capitain wrote:

> Ruby Quiz schrieb:
>
>>     class String
>>       def width
>>         inject(0) {|w, line| [w, line.chomp.size].max }
>>       end
>>     end
>> I just know I would have written width() as:
>>     map { |line| line.chomp.size }.max
>> Dave's is more efficient though.  It only ever keeps the highest  
>> number, instead
>> of building an Array of all the lengths.  Just one more reason  
>> inject() is the
>> one iterator to rule them all.  Thanks for trick #562, Dave!
>>
>
> I'm not sure about the efficiency. The inject() version builds a  
> new array on each pass, whereas the map() version builds only one  
> array. Even an inject() implementation without the arrays was  
> running slower than the map() implementation on my computer. inject 
> () is nice, but it definitely doesn't rule them all (sorry Robert :-).

I didn't make that very clear.

I was speaking of memory consumption.  map() has to copy the whole  
Array, while inject() does not.

James Edward Gray II