How to translate this Perl regex

ruby-talk
1

Someone said that Ruby can do anything that Perl does.
How would you write this Perl regex

$s =~ s/(pat1+)pat2(pat3*)/&foo($1,$2)/ge;

in Ruby?

It

  • does a global replace (/g) in one sweep
  • executes code (calls function) to create the replacement string (/e)
  • uses parts of the searched patterns (groupings) as parameters to foo

My books

  • Ruby in a Nutshell
  • The Ruby Way
    are very brief with respect to regexs and don’t give
    me a clue how to do this.
···

–
Helmut Leitner leitner@hls.via.at
Graz, Austria www.hls-software.com

2

Helmut Leitner wrote:

Someone said that Ruby can do anything that Perl does.
How would you write this Perl regex

$s =~ s/(pat1+)pat2(pat3*)/&foo($1,$2)/ge;

in Ruby?

str.gsub /(pat1+)pat2(pat3*)/ { |m| foo(m[1], m[2]) }

Note that it;s better to use m[1] and m[2] instead of $1/$2 …

Happy new year!

3

Helmut Leitner helmut.leitner@chello.at wrote in message news:3E116DDE.972A9081@chello.at…

Someone said that Ruby can do anything that Perl does.
How would you write this Perl regex

$s =~ s/(pat1+)pat2(pat3*)/&foo($1,$2)/ge;

in Ruby?

str = “There are 3*33 bottles of beer on the wall.”

def foo(a,o,b)
case o
when ‘+’ then (a.to_i + b.to_i).to_s
when ‘-’ then (a.to_i - b.to_i).to_s
when ‘*’ then (a.to_i * b.to_i).to_s
when ‘/’ then (a.to_i / b.to_i).to_s
end
end

p str.gsub(/^(\D+)(\d+)\s*([+-/])\s(\d+)(\D+)/) {$1+foo($2,$3,$4)+$5}