From: Mike Stok <mike@...>
Date: 2002-05-30T06:03:32+09:00
Subject: Re: Regexp in ranges as control

In article <3cf53223@news.mhogaming.com>, Sean Russell wrote:
> I've always liked the syntax:
> 
>         while gets
>                 print if /start/../end/
>         end
> 
> However, on a recent project, I tried to extend this concept:
> 
>         lines.readlines("somefile").each do |line|
>                 puts line if line === /start/../end/
>         end
> 
> This doesn't work, and I don't know why.  I can /get/ it to work, with 
> 
>         lines.readlines("somefile").each do |$_|
>                 puts $_ if /start/../end/
>         end

This is just like the perl...

"preamble
blah
start
sdfas
asdfas
asdfasdf
asdfasf
  end
postamble".each { |line|
    puts line if line =~ /start/ .. line =~ /end/
}

makes the variable explicit and works as expected.

> but I have to say that this really, really makes me uncomfortable.  Do I 
> /have/ to use the global variable $_ just to use regexps as switches?  Why?  
> You don't need them for other ranges.  For example, the following works:
> 
>         [1,2,3,4,5,6].each do |x|
>                 puts x if x === 3..5
>         end

Or

[1,2,3,4,5,6].each do |x|
     puts x if (3..5).include? x
end

A better explaniation would be forthcoming were I not busy.

Hope this helps,

Mike

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