oil AST

(CommandList
  children: [
    (C {(echo)} {(DQ ('Content-type: text/html'))})
    (C {(echo)} {(DQ )})
    (C {(echo)} 
      {
        (DQ ('<html><body bgcolor=') (EscapedLiteralPart token:<Lit_EscapedChar '\\"'>) (white) 
          (EscapedLiteralPart token:<Lit_EscapedChar '\\"'>) ('><h2>CGI Runtime Environment</h2>')
        )
      }
    )
    (C {(echo)} {(DQ ('<pre>'))})
    (AndOr ops:[Op_DPipe] children:[(C {(env)}) (C {(printenv)})])
    (C {(echo)} {(DQ ('</pre>'))})
    (C {(echo)} {(DQ ('<h3>Input stream is:</h3>'))})
    (C {(echo)} {(DQ ('<pre>'))})
    (C {(cat)} {(-)})
    (C {(echo)} {(DQ ('(end of input stream)</pre></body></html>'))})
    (ControlFlow token:<ControlFlow_Exit exit> arg_word:{(0)})
  ]
)