How do you convert "Hello, **world**!" to "Hello, <b>world</b>!" in Ruby?

bold.rb

text = <<"EOD"
Lorem**ipsum**dolorsitamet,
con*secteturadipiscing**elit**,
**sed****do**eiusmod**temporincididunt
utlabore**etdoloremagnaaliqua.
EOD

html = <<"EOD"
Lorem<b>ipsum</b>dolorsitamet,
con*secteturadipiscing<b>elit</b>,
<b>sed</b><b>do</b>eiusmod<b>temporincididunt
utlabore</b>etdoloremagnaaliqua.
EOD

def bold1(s)
  t = ''
  while s.match(/\*\*(.+?)\*\*/m)
    t += "#{$`}<b>#{$1}</b>"
    s = $'
  end
  t + s
end

def bold2(s)
  s.gsub(/\*\*(.+?)\*\*/m) do
    "<b>#{$1}</b>"
  end
end

puts bold1(text) == html #=> true
puts bold2(text) == html #=> true

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