From: Andreas Semt <as@...>
Date: 2005-01-13T02:03:30+09:00
Subject: Re: Comparing two files for equality

Nicholas Van Weerdenburg wrote:

> end is the end of an expression that returns an array.
> 
> # this is quivalent.
> a=files.map do |file|
> ...
> end
> a.uniq
> 
> # Since everything in ruby is an expression, you can do:
> files.map do |file|
> ...
> end.uniq
> 
> # making the expression explicit...
> (files.map do |file|
> ....
> end).uniq
> 
> Regards,
> Nick
> 

Thanks Nick!

Nice Ruby code.
It's every time a pleasure to see a solution by Florian.

Greetings,
Andreas



> On Thu, 13 Jan 2005 01:15:25 +0900, Andreas Semt <as@computer-leipzig.de> wrote:
> 
>>Florian Gross wrote:
>>
>>>def files_equal?(*files)
>>>  files.map do |file|
>>>    File.size file
>>>  end.uniq.size <= 1 and
>>>  files.map do |file|
>>>    File.read file
>>>  end.uniq.size <= 1
>>>end
>>>
>>
>>Could anybody please explain the "end.uniq.size" line?
>>Thanks!
>>
>>Greetings,
>>Andreas
>>
>>
>>>This ought to be slightly faster in the average case.
>>>
>>>Other optimizations would be reading the files line-wise in parallel and
>>>bailing out as soon as one of the lines differs.
>>>
>>
>>
> 
>