my $rxSpaces = qr{(?x)  # Use regex extended syntax to allow comments
   (?:                  # Open non-capturing group for alternation
      (?<= \A ) \s+     # Spaces preceded by beginning of string
      |                 # or
      (?<= \s ) \s+     # Spaces preceded by a single space
      |                 # or
      \s+ (?= \z )      # Spaces followed by end of string
   )                    # Close group
   };