From: Dave Thomas <Dave@...>
Date: 2001-05-05T10:14:32+09:00
Subject: [ruby-talk:14696] Re: bizarre eval resource problem solved

"Guy N. Hurst" <gnhurst@hurstlinks.com> writes:

> >>>
>  To determine pass/fail, there is a string in the 
> file (which is the srchStr in the example above) that is an expression 
> composed of regex's and logical operators, like:
> "!(/Error Count = [1-9]/ || /Abort/ || /[1-9] error/ || /fatal/)"
> <<<
> 
> 
> So you see, the string is in the file.  Since it is pre-existing,
> he can't be told to do it otherwise. This is a legacy code issue ;-)

No, but we can suggest he do it differently :)

I haven't performance tested this, but it does avoid the eval each
time around the loop. It uses the proof-of-concept eregex package
distributed with the Ruby source:

     require "eregex"

     pat = "/a/ | /b/"

     matcher = eval "proc {|str| str =~ " + pat + "}"

     while line = gets
       if matcher.call line
         puts line
       end
     end


Regards


Dave