From: "Bilyk, Alex" <ABilyk@...>
Date: 2008-04-03T09:16:31+09:00
Subject: Re: confused by 'test'.gsub(/.*/,'x')

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The point is that I don't understand why test.gsub(/.*/,'x') gives me
'xx', since .* means: zero or more of any character, except the newline
character, ...
-
Wybo
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I would venture to say this is exactly what it does. It finds two
matches and replaces them both with 'x'. The first match is an empty
string <zero>, while the second match is the full string <or more >.

Alex


-----Original Message-----
From: Januski, Ken [mailto:kjanuski@phillynews.com] 
Sent: Wednesday, April 02, 2008 3:08 PM
To: ruby-talk ML
Subject: Re: confused by 'test'.gsub(/.*/,'x')

Seems wrong to me as well. If you do a destructive gsub and test for
individual letters, e.g. /t.*/,'x', you get 'tex' as you'd expect. Seems
wrong to get the double 'x', when you use your example. Of course my
background is Perl and I believe that's how it would work there.

irb(main):016:0> 'test'.gsub!(/.*/, 'x')
=> "xx"
irb(main):017:0> 'test'.gsub!(/e.*/, 'x')
=> "tx"
irb(main):018:0> 'test'.gsub!(/s.*/, 'x')
=> "tex"
irb(main):019:0> 'test'.gsub!(/t.*/, 'x')
=> "x"
irb(main):020:0> 'test'.gsub!(/st.*/, 'x')
=> "tex"

Ken


-----Original Message-----
From: Wybo Dekker [mailto:wybo@servalys.nl] 
Sent: Wednesday, April 02, 2008 5:39 PM
To: ruby-talk ML
Subject: Re: confused by 'test'.gsub(/.*/,'x')

Jens Wille wrote:

> as soon as you anchor the regexp at the beginning of the string it 
> gives the expected result:
> 
> irb> 'test'.gsub(/\A.*/) { |m| p m; 'x'}
> "test"
> =>"x"
> 
> or just do:
> 
> irb> 'test'.sub(/.*/) { |m| p m; 'x'}
> "test"
> =>"x"

sure, that works, and so does test.gsub(/.+/,'x').
The point is that I don't understand why test.gsub(/.*/,'x') gives me
'xx', since .* means: zero or more of any character, except the newline
character, i.e.: all of the string should be replaced with a single x,
as far as I can see.


--
Wybo