Negating options

[Jari Aalto]

John A Meinel <john at arbash-meinel.com> writes:

> Erik Bågfors wrote:
>>> ... it's usefult to be able to negate boolean options.  
>>> could make '--no' be a special option:
>>>
>>> $ bzr revert --no reprocess --merge-type weave
>
> I would like to see us be very regular about this, rather than being
> proper English.
> So while "dont-set-scripts-executable" is better English,
> "--no-set-scripts-executable" is more regular, and easier to figure out.
>
> So I would propose that we use either "--no-*" everywhere, or maybe a
> mix of "--no-*" and "--non-*". --no- is for actions/nouns, --non- is for
> adjectives. --non-empty, --no-default. but while --no-empty is a little
> unclear, it is more regular.

[1] Perl uses:  --no<option>

  http://perldoc.perl.org/Getopt/Long.html#Summary-of-Option-Specifications

  The option does not take an argument and may be negated by prefixing
  it with "no" or "no-". E.g. "foo!" will allow --foo (a value of 1
  will be assigned) as well as --nofoo and --no-foo (a value of 0 will
  be assigned). If the option has aliases, this applies to the aliases
  as well.

[2] GNU uses: --options  .. but doesn't define negations

   http://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html

[3] Autoconf (./configure) uses:  --{enable|disable}-option

SUMMARY

I vote against mixed choices (allowing both --no-* and --non-*); it's
not programmable friendly from 3rd party front ends (like Emacs). 

The autoconf notation is too verbose. 

Personally the minimized typing is good thing, so I would lean to
short (Perl) notation:

    --no<option> 

But as good is:

    --no-<option>

Jari