oil AST

(command.CommandList
  children: [
    (command.ShAssignment
      pairs: [
        (assign_pair
          lhs: (sh_lhs_expr.Name name:command)
          op: assign_op.Equal
          rhs: 
            {
              (DQ <"printf 'a"> <Id.Lit_Other '\\'> <nb> <Id.Lit_Other '\\'> <nc> <Id.Lit_Other '\\'> 
                <"n'">
              )
            }
          spids: [4]
        )
      ]
    )
    (C {<mkfifo>} {<first>})
    (C {<mkfifo>} {<rest0>})
    (command.Subshell
      command_list: 
        (command.CommandList
          children: [
            (command.Sentence
              child: 
                (command.Pipeline
                  children: [
                    (C {<eval>} {(DQ ($ Id.VSub_DollarName '$command'))})
                    (C {<tee>} 
                      {
                        (command_sub
                          left_token: <Id.Left_ProcSubOut '>('>
                          command_list: 
                            (command.CommandList
                              children: [
                                (command.Simple
                                  words: [{<head>} {<-1>}]
                                  redirects: [
                                    (redir.Redir
                                      op: <Id.Redir_Great '>'>
                                      fd: -1
                                      arg_word: {<first>}
                                    )
                                  ]
                                )
                              ]
                            )
                        )
                      }
                    )
                    (command.Simple
                      words: [{<tail>} {<-n>} {<Id.Lit_Other '+'> <2>}]
                      redirects: [(redir.Redir op:<Id.Redir_Great '>'> fd:-1 arg_word:{<rest0>})]
                    )
                  ]
                  negated: F
                )
              terminator: <Id.Op_Amp _>
            )
          ]
        )
    )
    (C {<cat>} {<first>})
    (C {<mkfifo>} {<rest1>})
    (command.Subshell
      command_list: 
        (command.CommandList
          children: [
            (command.Sentence
              child: 
                (command.Pipeline
                  children: [
                    (C {<cat>} {<rest0>})
                    (C {<tee>} 
                      {
                        (command_sub
                          left_token: <Id.Left_ProcSubOut '>('>
                          command_list: 
                            (command.CommandList
                              children: [
                                (command.Simple
                                  words: [{<head>} {<-1>}]
                                  redirects: [
                                    (redir.Redir
                                      op: <Id.Redir_Great '>'>
                                      fd: -1
                                      arg_word: {<first>}
                                    )
                                  ]
                                )
                              ]
                            )
                        )
                      }
                    )
                    (command.Simple
                      words: [{<tail>} {<-n>} {<Id.Lit_Other '+'> <2>}]
                      redirects: [(redir.Redir op:<Id.Redir_Great '>'> fd:-1 arg_word:{<rest1>})]
                    )
                  ]
                  negated: F
                )
              terminator: <Id.Op_Amp _>
            )
          ]
        )
    )
    (C {<cat>} {<first>})
    (C {<mkfifo>} {<rest2>})
    (command.Subshell
      command_list: 
        (command.CommandList
          children: [
            (command.Sentence
              child: 
                (command.Pipeline
                  children: [
                    (C {<cat>} {<rest1>})
                    (C {<tee>} 
                      {
                        (command_sub
                          left_token: <Id.Left_ProcSubOut '>('>
                          command_list: 
                            (command.CommandList
                              children: [
                                (command.Simple
                                  words: [{<head>} {<-1>}]
                                  redirects: [
                                    (redir.Redir
                                      op: <Id.Redir_Great '>'>
                                      fd: -1
                                      arg_word: {<first>}
                                    )
                                  ]
                                )
                              ]
                            )
                        )
                      }
                    )
                    (command.Simple
                      words: [{<tail>} {<-n>} {<Id.Lit_Other '+'> <2>}]
                      redirects: [(redir.Redir op:<Id.Redir_Great '>'> fd:-1 arg_word:{<rest2>})]
                    )
                  ]
                  negated: F
                )
              terminator: <Id.Op_Amp _>
            )
          ]
        )
    )
    (C {<cat>} {<first>})
    (C {<mkfifo>} {<rest3>})
    (command.Subshell
      command_list: 
        (command.CommandList
          children: [
            (command.Sentence
              child: 
                (command.Pipeline
                  children: [
                    (C {<cat>} {<rest2>})
                    (C {<tee>} 
                      {
                        (command_sub
                          left_token: <Id.Left_ProcSubOut '>('>
                          command_list: 
                            (command.CommandList
                              children: [
                                (command.Simple
                                  words: [{<head>} {<-1>}]
                                  redirects: [
                                    (redir.Redir
                                      op: <Id.Redir_Great '>'>
                                      fd: -1
                                      arg_word: {<first>}
                                    )
                                  ]
                                )
                              ]
                            )
                        )
                      }
                    )
                    (command.Simple
                      words: [{<tail>} {<-n>} {<Id.Lit_Other '+'> <2>}]
                      redirects: [(redir.Redir op:<Id.Redir_Great '>'> fd:-1 arg_word:{<rest3>})]
                    )
                  ]
                  negated: F
                )
              terminator: <Id.Op_Amp _>
            )
          ]
        )
    )
  ]
)