From: Gavin Sinclair <gsinclair@...>
Date: 2003-10-13T09:27:58+09:00
Subject: Re: Ruby idiom for all matches in a string

> Hi --
>
> On Mon, 13 Oct 2003, Gavin Sinclair wrote:
>
>> On Monday, October 13, 2003, 8:34:41 AM, David wrote:
>>
>> > What's the ruby idiom for all the matches in a string.
>>
>> > x="ABA  ABBBA CBBA"
>> > /A(B+)/.match(x)
>>
>> > Ultimately, I want to get [ "B", "BBB" ]
>>
>> > Thanks
>>
>>
>>     /A(B+)/.match(x).captures
>
> That won't do it; it only gets the first one.  To get them all, you can
> use String#scan:
>
>   irb(main):008:0> x
>   > "ABA  ABBBA CBBA"
>   irb(main):009:0> x.scan(/A(B+)/)
>   => [["B"], ["BBB"]]
>
> The reason you get an array-of-arrays (which you may have to flatten
> before it's useful) is that each scan (i.e., each application of the
> regex) generates a new array of captures.  (This starts to look less
> cumbersome when you've got more than one capture.)  Also, #scan takes a
> block, which can be handy.
>
> David

Ah yes, #scan.  You know, as much as I love #scan, it is probably the only
method I have to look up in 'ri' _every_ time I use it.  I can never
remember whether the block form yields an array or a matchdata or a string
or what.

Gavin