[getopt-sig] Parse arguments according to a usage message?

[David Boddie]

Having read the messages about separating mechanics from semantics

http://mail.python.org/pipermail/getopt-sig/2002-February/000039.html

and generating usage messages automatically

http://mail.python.org/pipermail/getopt-sig/2002-February/000024.html

I wonder whether there is any mileage in using part of the class that I
mentioned in the "RFC: Option Parsing Libraries" thread in python-dev?

http://www-solar.mcs.st-and.ac.uk/~davidb/Software/Python/cmdsyntax/

Here's some abridged output from the test.py script included in the
cmdsyntax.zip archive found from the page above. Apologies for the amount
of output, but I'm trying to illustrate the capabilities of the parser.

The first example allows either the short or long form of switches/options
to be specified, although the parser doesn't know that -d and --directory
might be equivalent in this case.

  [davidb@bunsen CMDSyntax]$ test.py -d output myfile
  Syntax: ./test.py [(-d dir) | --directory=dir] infile
  Ordered optional arguments? [y/n] n

[Removed some output here...]

  First match found:

  dir     :       output
  infile  :       myfile
  -d      :       1

  [davidb@bunsen CMDSyntax]$ test.py --directory=output myfile
  Syntax: ./test.py [(-d dir) | --directory=dir] infile
  Ordered optional arguments? [y/n] n

[Removed some output here...]

  First match found:

  infile          :               myfile
  --directory     :               output


Arguments can be optional and may contain optional arguments of their
own.

  [davidb@bunsen CMDSyntax]$ test.py -a -b bernard
  Syntax: ./test.py [-a] [[-b badger] -c]
  Ordered optional arguments? [y/n] n

[Removed some output here...]

  Quick match with command line? [y/n] y
  No matches found

  [davidb@bunsen CMDSyntax]$ test.py -b bernard -c
  Syntax: ./test.py [-a] [[-b badger] -c]
  Ordered optional arguments? [y/n] n

[Removed some output here...]

  Quick match with command line? [y/n] y
  First match found:

  -b      :       1
  -c      :       1
  badger  :       bernard


Optional arguments placed together can be ordered arbitrarily without
disturbing mandatory arguments which must occur in the correct order.

  [davidb@bunsen CMDSyntax]$ test.py input -b hello -a world output
  Syntax: ./test.py infile [-a abacus] [-b binary] outfile [-c computer]
  Ordered optional arguments? [y/n] n

[Removed some output here...]

  Quick match with command line? [y/n] n
  First match found:

  infile  :       input
  binary  :       hello
  abacus  :       world
  -b      :       1
  -a      :       1
  outfile :       output

Is this sort of thing useful, or relevant to the discussion?

David

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