Define default read/write options and add items to it

Define the functions that read() or write() must call to import or export data for the different types (formats).

read_write_option(new_type)

Arguments

new_type

A data.frame with four columns: type, read_fun, read_header and write_fun containing each a single character string or NA. type is the usual extension for this type of file, e.g., png for PNG images, read_fun, read_header and write_fun are character strings with "pkg::fun" format ("pkg" is the package containing the function and "fun" is the function name), or just "fun" if the function is visible on the search path.

Value

The data.frame with all known formats is returned invisibly. The same data.frame is also saved in the read_write option, and can be retrieved directly with getOption("read_write").

See also

read(), getOption()

Author

Philippe Grosjean phgrosjean@sciviews.org

Examples

# The default options
(read_write_option())
#> # A tibble: 44 × 5
#>    type     read_fun          read_header         write_fun              comment
#>    <chr>    <chr>             <chr>               <chr>                  <chr>  
#>  1 csv      data.table::fread data.io::hread_text data.table::fwrite     comma …
#>  2 csv_alt  readr::read_csv   data.io::hread_text readr::write_csv       comma …
#>  3 csv2     data.table::fread data.io::hread_text data.table::fwrite     semico…
#>  4 csv2_alt readr::read_csv2  data.io::hread_text NA                     semico…
#>  5 xlcsv    readr::read_csv   data.io::hread_text readr::write_excel_csv write …
#>  6 tsv      data.table::fread data.io::hread_text data.table::fwrite     tab se…
#>  7 tsv_alt  readr::read_tsv   data.io::hread_text readr::write_tsv       tab se…
#>  8 fwf      readr::read_fwf   data.io::hread_text NA                     fixed …
#>  9 log      readr::read_log   NA                  NA                     standa…
#> 10 rds      readr::read_rds   NA                  readr::write_rds       R data…
#> # ℹ 34 more rows
# To add a new type:
tail(read_write_option(data.frame(type = "png", read_fun = "png::readPNG",
  read_header = NA, write_fun = "png::writePNG", comment = "PNG image")))
#> # A tibble: 6 × 5
#>   type     read_fun        read_header write_fun        comment                 
#>   <chr>    <chr>           <chr>       <chr>            <chr>                   
#> 1 sas7bdat haven::read_sas NA          haven::write_sas SAS format (sas7bdat)   
#> 2 sav      haven::read_sav NA          haven::write_sav SPSS .sav format        
#> 3 zsav     haven::read_sav NA          haven::write_sav SPSS .zsav format       
#> 4 por      haven::read_por NA          NA               SPSS .por format        
#> 5 xpt      haven::read_xpt NA          haven::write_xpt SPSS transport format (…
#> 6 png      png::readPNG    NA          png::writePNG    PNG image