R: A function to create an instance of a parser object

OptionParser {optparse}

R Documentation

A function to create an instance of a parser object

Description

This function is used to create an instance of a parser object which when combined with the parse_args, make_option, and add_option methods is very useful for parsing options from the command line.

Usage

OptionParser(
  usage = "usage: %prog [options]",
  option_list = list(),
  add_help_option = TRUE,
  prog = NULL,
  description = "",
  epilogue = "",
  formatter = IndentedHelpFormatter
)

Arguments

`usage`	The program usage message that will printed out if `parse_args` finds a help option, `%prog` is substituted with the value of the `prog` argument.
`option_list`	A list of of `OptionParserOption` instances that will define how `parse_args` reacts to command line options. `OptionParserOption` instances are usually created by `make_option` and can also be added to an existing `OptionParser` instance via the `add_option` function.
`add_help_option`	Whether a standard help option should be automatically added to the `OptionParser` instance.
`prog`	Program name to be substituted for `%prog` in the usage message (including description and epilogue if present), the default is to use the actual Rscript file name if called by an Rscript file and otherwise keep `%prog`.
`description`	Additional text for `print_help` to print out between usage statement and options statement
`epilogue`	Additional text for `print_help` to print out after the options statement
`formatter`	A function that formats usage text. The function should take only one argument (an `OptionParser()` object). Default is `IndentedHelpFormatter()`. The other builtin formatter provided by this package is `TitledHelpFormatter()`.

Value

An instance of the OptionParser class.

Author(s)

Trevor Davis.

References

Python's optparse library, which inspired this package, is described here: https://docs.python.org/3/library/optparse.html