From: Chris <chris@...>
Date: 2002-04-16T08:02:55+09:00
Subject: Re: need help on using Ruby to replace some SED expressions

In article <chris-CF9136.16303415042002@corp.supernews.com>,
 Chris <chris@cmb-enterprises.com> wrote:

> #!/usr/local/bin/ruby
> 
> class String
>    def eval_math!
>       while self =~ /(log|sin|cos|tan)\s+(\d+)/
>          sub! $&, eval("Math.#{$1} #{$2}").to_s
>       end
>       re = /\(\s*[\-+]?\d+(\.\d+)?(\s*[+-\/*]\s*[\-+]?\d+(\.\d+)?)*\s*\)/
>       while self =~ re
>          x = $&
>          sub! x, eval(x).to_s
>       end
>       self
>    end
> end

# Much improved version.  Switched sub! with self[...] = "something"
# idiom.

class String
 def eval_math!
  while self =~ /(log|sin|cos|tan)\s+(\d+)/
   sub! $&, eval("Math.#{$1} #{$2}").to_s
  end
  re = /\(\s*[\-+]?\d+(\.\d+)?(\s*[\-+\/*]\s*[\-+]?\d+(\.\d+)?)*\s*\)/
  while self =~ re
   self[$&] = eval($&).to_s
  end
  self
 end
end

> ARGV.each do |filename|
>    file = open(filename, "r")
>    text = file.readlines
>    file.close
>    text.collect! do |line|
>       line.sub!(/^(\s*\S*)\.(\S*)/, "#{$1}$#{$2}")
>       line.sub!("@", "^")
>       line.eval_math!
>    end
>    file = open(filename, "w")
>    file.write(text.join)
>    file.close
> end