regex planning

gistfile1.rb

"123-456-hello" case-of: {
  /(\d+)-(\d+)-(?<foo>\w+)/ ->
    { \0 print -- prints 123-456-hello
      \1 print -- prints 123
      foo print -- prints hello (\2 available too?)
    } call
}

"123-456-hello" replace: /(\d+)-(?<foo>\w+)/ with: {
  foo .. "-" .. \1
}