optparse 1.7.5

• We no longer coerce the type of an option default to match that of
  its type argument when action = "callback".
  Thanks husheng (@hs3434) for bug report (#47).

optparse 1.7.4

• Revises vignette engine specification in the DESCRIPTION to suppress new CRAN check NOTE (#43).

optparse 1.7.3

• The errors raised by parse_args() (and parse_args2()) are now of class "optparse_parse_error".

  When interactive() is FALSE we now print out a usage string followed by
  a (less verbose) error message.

• Throws a more informative error message for unknown short flags when positional_arguments=TRUE.
  Thanks Greg Minshall for bug report (#42).

optparse 1.7.1

• Add a formatter argument to OptionParser() for a function to format the usage message (#30).
  By default uses the new function IndentedHelpFormatter().
  {optparse} also provides the new function TitledHelpFormatter().
  Thanks Ni Huang for suggestion.

optparse 1.6.6

• Throws an error for unknown short flags and long flags when positional_arguments=TRUE.
  Thanks Greg Minshall for bug report (#34).
• If the callback parameter of add_option / make_option is not NULL then
  the default of action is now "callback". Thanks Greg Minshall for suggestion (#35).
• Better documentation of action=="callback" in the man page for add_option and make_option.
  Thanks Greg Minshall for bug report (#35).

optparse 1.6.4

• Fixes bug in printing help for action=="callback" when metavar==NULL (#29).
  Thanks Ni Huang for bug report.
• Throws an error when passed short flags more than one letter long (#32).
  Thanks Gautier Richard for bug report.

optparse 1.6.2

• Fixs a parsing bug when action=="callback" and positional_argument==TRUE (#28). Thanks Ni Huang for bug report.

optparse 1.6.1

• Improve accuracy of README (#27). Thanks Alex Penson for bug report.

optparse 1.6.0

• Support for callback actions (#26). Thanks Gyu Jin Choi for patch.