From: Robert Klemme <shortcutter@...>
Date: 2007-05-27T18:25:02+09:00
Subject: Re: Strange behavior of String.scan

On 27.05.2007 10:17, Alex Young wrote:
> H�vard Moen wrote:
>> When I use String.scan with a block and just one group the result ends
>> up as an array. More than one group works as expected. A small example 
>> to demonstrate:
>>
>> --ruby code start--
>> data = '   lb method member observed
>>    monitor all http
>>    member 192.168.1.68:http'
>> data.scan(/monitor all (.*)$/) do |monitor|
>>   puts monitor.inspect
>> end
>> data.scan(/member ([0-9.]+):(.*)/) do |adress, port|
>>   puts adress.inspect
>>   puts port.inspect
>> end
>> --ruby code end--
>>
>> gives me:
>> ["http"]
>> "192.168.1.68"
>> "http"
> 
> That's expected.  What scan actually yields to the block is an array, 
> and in your second example that array is being automatically split into 
> its component parts because you've given more than one block parameter 
> in the pipes.  A third example should make it clear:
> 
> irb(main):004:0> data.scan(/member ([0-9.]+):(.*)/) do |match|
> irb(main):005:1*   puts match.inspect
> irb(main):006:1> end
> ["192.168.1.68", "http"]

irb(main):001:0> "abc".scan(/abc/) {|m| p m}
"abc"
=> "abc"
irb(main):002:0> "abc".scan(/(a)bc/) {|m| p m}
["a"]
=> "abc"
irb(main):003:0> "abc".scan(/(a)(b)c/) {|m| p m}
["a", "b"]
=> "abc"

	robert