make_option {optparse}

Functions to enable our OptionParser to recognize specific command line options.

Description

add_option adds a option to a prexisting OptionParser instance whereas make_option is used to create a list of OptionParserOption instances that will be used in the option_list argument of the OptionParser function to create a new OptionParser instance.

Usage

make_option(
  opt_str,
  action = NULL,
  type = NULL,
  dest = NULL,
  default = NULL,
  help = "",
  metavar = NULL,
  callback = NULL,
  callback_args = NULL
)

add_option(
  object,
  opt_str,
  action = NULL,
  type = NULL,
  dest = NULL,
  default = NULL,
  help = "",
  metavar = NULL,
  callback = NULL,
  callback_args = NULL
)

Arguments

opt_str

A character vector containing the string of the desired long flag comprised of “–” followed by a letter and then a sequence of alphanumeric characters and optionally a string of the desired short flag comprised of the “-” followed by a letter.

action

A character string that describes the action optparse should take when it encounters an option, either “store”, “store_true”, “store_false”, or “callback”. An action of “store” signifies that optparse should store the specified following value if the option is found on the command string. “store_true” stores TRUE if the option is found and “store_false” stores FALSE if the option is found. “callback” stores the return value produced by the function specified in the callback argument. If callback is not NULL then the default is “callback” else “store”.

type

A character string that describes specifies which data type should be stored, either “logical”, “integer”, “double”, “complex”, or “character”. Default is “logical” if action %in% c("store_true", store_false), typeof(default) if action == "store" and default is not NULL and “character” if action == "store" and default is NULL. “numeric” will be converted to “double”.

dest

A character string that specifies what field in the list returned by parse_args should optparse store option values. Default is derived from the long flag in opt_str.

default

The default value optparse should use if it does not find the option on the command line.

help

A character string describing the option to be used by print_help in generating a usage message. %default will be substituted by the value of default.

metavar

A character string that stands in for the option argument when printing help text. Default is the value of dest.

callback

A function that executes after the each option value is fully parsed. It's value is assigned to the option and its arguments are the option S4 object, the long flag string, the value of the option, the parser S4 object, and ....

callback_args

A list of additional arguments passed to callback function (via do.call).

object

An instance of the OptionParser class

Value

Both make_option and add_option return instances of class OptionParserOption.

Author(s)

Trevor Davis.

References

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

See Also

parse_args OptionParser

Examples

   make_option("--longflag")
   make_option(c("-l", "--longflag"))
   make_option("--integer", type = "integer", default = 5)
   make_option("--integer", default = as.integer(5))  # same as previous

   # examples from package vignette
   make_option(c("-v", "--verbose"), action = "store_true", default = TRUE,
       help = "Print extra output [default]")
   make_option(c("-q", "--quietly"), action = "store_false",
     dest = "verbose", help = "Print little output")
   make_option(c("-c", "--count"), type = "integer", default = 5,
       help = "Number of random normals to generate [default %default]",
       metavar = "number")
   make_option("--generator", default = "rnorm",
       help = "Function to generate random deviates [default \"%default\"]")
   make_option("--mean", default = 0,
       help = "Mean if generator == \"rnorm\" [default %default]")
   make_option("--sd", default = 1, metavar = "standard deviation",
       help = "Standard deviation if generator == \"rnorm\" [default %default]")