oil AST

(command.CommandList
  children: [
    (C {<Id.KW_Set set>} {<-o>} {<nounset>})
    (C {<Id.KW_Set set>} {<-o>} {<pipefail>})
    (C {<Id.KW_Set set>} {<-o>} {<errexit>})
    (command.ShFunction
      name: basic-head
      body: 
        (command.BraceGroup
          children: [
            (C {<local>} {<Id.Lit_VarLike 'title='> ($ Id.VSub_Number '$1')})
            (command.Simple
              words: [{<cat>}]
              redirects: [
                (redir.HereDoc
                  op: <Id.Redir_DLess '<<'>
                  fd: -1
                  here_begin: {<EOF>}
                  here_end_span_id: 83
                  stdin_parts: [
                    <'<!DOCTYPE html>\n'>
                    <'<html>\n'>
                    <'  <head>\n'>
                    <'    <title>'>
                    ($ Id.VSub_DollarName '$title')
                    <'</title>\n'>
                    <'    <style>\n'>
                    <'      body {\n'>
                    <'        margin: 0 auto;\n'>
                    <'        width: 40em;\n'>
                    <'      }\n'>
                    <'      #home-link {\n'>
                    <'        text-align: right;\n'>
                    <'      }\n'>
                    <'    </style>\n'>
                    <'  </head>\n'>
                    <'  <body>\n'>
                    <'    <p id='>
                    <Id.Right_DoubleQuote '"'>
                    <home-link>
                    <Id.Right_DoubleQuote '"'>
                    <'>\n'>
                    <'      <a href='>
                    <Id.Right_DoubleQuote '"'>
                    </>
                    <Id.Right_DoubleQuote '"'>
                    <'>oilshell.org</a>\n'>
                    <'    </p>\n'>
                    <'    <h3>'>
                    ($ Id.VSub_DollarName '$title')
                    <'</h3>\n'>
                    <'    <p>\n'>
                  ]
                )
              ]
            )
          ]
        )
    )
    (command.ShFunction
      name: basic-tail
      body: 
        (command.BraceGroup
          children: [
            (command.Simple
              words: [{<cat>}]
              redirects: [
                (redir.HereDoc
                  op: <Id.Redir_DLess '<<'>
                  fd: -1
                  here_begin: {<EOF>}
                  here_end_span_id: 102
                  stdin_parts: [<'  </body>\n'> <'</html>\n'>]
                )
              ]
            )
          ]
        )
    )
    (C {(DQ ($ Id.VSub_At '$@'))})
  ]
)