prelude: |
  # All elements are 7-bit ASCII Strings (the dominant real-world join case).
  # Distinct objects so large-N cases exercise realistic heap/cache behavior.
  a100_1    = Array.new(100)    { "a" * 1  }
  a100_8    = Array.new(100)    { "a" * 8  }
  a100_40   = Array.new(100)    { "a" * 40 }
  a1k_1     = Array.new(1000)   { "a" * 1  }
  a1k_8     = Array.new(1000)   { "a" * 8  }
  a1k_40    = Array.new(1000)   { "a" * 40 }
  a100k_1   = Array.new(100000) { "a" * 1  }
  a100k_8   = Array.new(100000) { "a" * 8  }
  a100k_40  = Array.new(100000) { "a" * 40 }

benchmark:
  # separator " " (space)
  join_sp_n100_e1:    a100_1.join(" ")
  join_sp_n100_e8:    a100_8.join(" ")
  join_sp_n100_e40:   a100_40.join(" ")
  join_sp_n1k_e1:     a1k_1.join(" ")
  join_sp_n1k_e8:     a1k_8.join(" ")
  join_sp_n1k_e40:    a1k_40.join(" ")
  join_sp_n100k_e1:   a100k_1.join(" ")
  join_sp_n100k_e8:   a100k_8.join(" ")
  join_sp_n100k_e40:  a100k_40.join(" ")
  # separator "\n" (newline)
  join_nl_n100_e1:    a100_1.join("\n")
  join_nl_n100_e8:    a100_8.join("\n")
  join_nl_n100_e40:   a100_40.join("\n")
  join_nl_n1k_e1:     a1k_1.join("\n")
  join_nl_n1k_e8:     a1k_8.join("\n")
  join_nl_n1k_e40:    a1k_40.join("\n")
  join_nl_n100k_e1:   a100k_1.join("\n")
  join_nl_n100k_e8:   a100k_8.join("\n")
  join_nl_n100k_e40:  a100k_40.join("\n")