read-parquet-6.md
In nanoparquet: Read and Write 'Parquet' Files

REPEATED columns, no LIST

Code
  as.data.frame(read_parquet(pf))
Output
    Int32_list             String_list
  1 0, 1, 2, 3     foo, zero, one, two
  2                              three
  3          4                    four
  4 5, 6, 7, 8 five, six, seven, eight

Only 3-layer LIST is supported for now

Code
  as.data.frame(read_parquet(pf))
Condition
  Error in `read_parquet()`:
  ! Only three-layer LIST columns are supported, could not read Parquet file at 'data/old_list_structure.parquet' @ lib/ParquetReader.cpp:202

LIST

Code
  as.data.frame(read_parquet(test_path("data/list-req-req.parquet")))
Output
          a
  1 1, 2, 3
  2        
  3       4
Code
  as.data.frame(read_parquet(test_path("data/list-req-opt.parquet")))
Output
           a
  1 1, NA, 3
  2         
  3        4
Code
  as.data.frame(read_parquet(test_path("data/list-opt-req.parquet")))
Output
          a
  1 1, 2, 3
  2        
  3    NULL
  4       4
Code
  as.data.frame(read_parquet(test_path("data/list-opt-opt.parquet")))
Output
           a
  1 1, NA, 3
  2         
  3     NULL
  4        4

Code
  as.data.frame(read_parquet(test_path("data/list-v2-req-req.parquet")))
Output
          a
  1 1, 2, 3
  2        
  3       4
Code
  as.data.frame(read_parquet(test_path("data/list-v2-req-opt.parquet")))
Output
           a
  1 1, NA, 3
  2         
  3        4
Code
  as.data.frame(read_parquet(test_path("data/list-v2-opt-req.parquet")))
Output
          a
  1 1, 2, 3
  2        
  3    NULL
  4       4
Code
  as.data.frame(read_parquet(test_path("data/list-v2-opt-opt.parquet")))
Output
           a
  1 1, NA, 3
  2         
  3     NULL
  4        4

Code
  read_parquet_page(pf, pgoff)[elts]
Output
  $has_repetition_levels
  [1] TRUE

  $has_definition_levels
  [1] TRUE

  $num_values
  [1] 10

  $num_rows
  [1] NA

Code
  read_parquet_page(pf2, pgoff2)[elts]
Output
  $has_repetition_levels
  [1] TRUE

  $has_definition_levels
  [1] TRUE

  $num_values
  [1] 5

  $num_rows
  [1] NA

Code
  read_parquet_page(pf3, pgoff3)[elts]
Output
  $has_repetition_levels
  [1] TRUE

  $has_definition_levels
  [1] TRUE

  $num_values
  [1] 5

  $num_rows
  [1] NA

Code
  read_parquet_page(pf4, pgoff4)[elts]
Output
  $has_repetition_levels
  [1] TRUE

  $has_definition_levels
  [1] TRUE

  $num_values
  [1] 6

  $num_rows
  [1] NA

Code
  read_parquet_page(pf5, pgoff5)[elts]
Output
  $has_repetition_levels
  [1] TRUE

  $has_definition_levels
  [1] TRUE

  $num_values
  [1] 6

  $num_rows
  [1] NA