From: Filipe <filipedlarcanjo@...>
Date: 2007-09-30T07:25:06+09:00
Subject: Regular Expresion Error?

Hello all,

According to the Regular Expressions section of the following ruby
guide: http://www.ruby-doc.org/docs/ProgrammingRuby/html/tut_stdtypes.html,
the piece of code bellow should have returned "He<<ll>>o", instead of
"No match". Has anyone got an idea on why it isn't working?

Notice that if I tell the interpreter how big \w should be in an
explicit way by adding {1,1}, the expected result is given.

def showRE(a,re)
  #re = Regexp.new(re) if re.class==String
  #re=Regexp.new(re.to_s) if re.class==Integer
  if a=~re
    "#{$`}<<#{$&}>>#{$'}"
  else
    "no match"
  end
end

puts showRE("Hello", /(\w)\1/)          #=> no match
puts showRE("Hello", /(\w{1,1})\1/)   #=> He<<ll>>o

Thanks in advance for helping