oil AST

(command.CommandList
  children: [
    (C {<set>} {<-e>})
    (C {<source>} {($ Id.VSub_DollarName TRAVIS_BUILD_DIR) <'/ci/travis_env_common.sh'>})
    (C {<export>} 
      {<Id.Lit_VarLike 'PARQUET_ARROW_VERSION='> 
        (command_sub
          left_token: <Id.Left_DollarParen '$('>
          child: (C {<git>} {<rev-parse>} {<HEAD>})
          right: <Id.Eof_RParen _>
        )
      }
    )
    (C {<export>} {<Id.Lit_VarLike 'PARQUET_BUILD_TOOLCHAIN='> ($ Id.VSub_DollarName CPP_TOOLCHAIN)})
    (command.ShAssignment
      pairs: [
        (assign_pair
          lhs: (sh_lhs_expr.Name left:<Id.Lit_VarLike 'PARQUET_DIR='> name:PARQUET_DIR)
          op: assign_op.Equal
          rhs: {($ Id.VSub_DollarName TRAVIS_BUILD_DIR) <'/parquet'>}
          spids: [84]
        )
      ]
      redirects: []
    )
    (C {<mkdir>} {<-p>} {($ Id.VSub_DollarName PARQUET_DIR)})
    (C {<git>} {<clone>} {<https> <Id.Lit_Colon ':'> <'//github.com/apache/parquet-cpp.git'>} 
      {($ Id.VSub_DollarName PARQUET_DIR)}
    )
    (C {<pushd>} {($ Id.VSub_DollarName PARQUET_DIR)})
    (C {<mkdir>} {<build-dir>})
    (C {<cd>} {<build-dir>})
    (C {<cmake>} {<-GNinja>} {<-DCMAKE_BUILD_TYPE> <Id.Lit_Equals '='> <debug>} 
      {<-DCMAKE_INSTALL_PREFIX> <Id.Lit_Equals '='> ($ Id.VSub_DollarName ARROW_PYTHON_PARQUET_HOME)} {<-DPARQUET_BOOST_USE_SHARED> <Id.Lit_Equals '='> <off>} 
      {<-DPARQUET_BUILD_BENCHMARKS> <Id.Lit_Equals '='> <off>} {<-DPARQUET_BUILD_EXECUTABLES> <Id.Lit_Equals '='> <off>} 
      {<-DPARQUET_BUILD_TESTS> <Id.Lit_Equals '='> <off>} {<..>}
    )
    (C {<ninja>})
    (C {<ninja>} {<install>})
    (C {<popd>})
  ]
)