Bug #7537: OptionParser treats negative digits as options

• Status: Closed
• Assignee: nobu (Nobuyoshi Nakada)
• Target version: -
• ruby -v: 1.9.3(p0, p327 both)

[prijutme4ty (Ilya Vorontsov)]

Is it intentional that negative digits are treated as options?
If I use negative digit as an argument of an option, it is treated as a number

OptionParser.new {|opts|
opts.on('-p','--pvalue VAL', Integer, 'P-value') {|v| puts "P-value: #{v}" }
}.parse!

ruby my_test.rb -p -1 works normally

But if I use it as optional argument of an option:

OptionParser.new {|opts|
opts.on('-p','--pvalue [VAL]', Integer, 'P-value') {|v| puts "P-value: #{v}" }
}.parse!

ruby my_test.rb -p -1 fails with "Invalid option -1"

Also I can't use it as non-optional argument

OptionParser.new {|opts|
opts.on('-n', 'no Pvalue argument, other arguments only') {}
}.parse!
puts ARGV

ruby my_test.rb -1 also fails with "Invalid option -1"

[prijutme4ty (Ilya Vorontsov)]

In my opinion, negative numbers shouldn't be treated as option keys unless it was explicitly specified. In other cases them should be treated as usual parameters.

[zzak (zzak _)]

• Category set to lib
• Assignee set to nobu (Nobuyoshi Nakada)

[usa (Usaku NAKAMURA)]

• Status changed from Open to Assigned

[prijutme4ty (Ilya Vorontsov)]

Sent a pull-request. https://github.com/ruby/ruby/pull/259
I've made changes the same way as python do -- http://docs.python.org/dev/library/argparse.html#arguments-containing
This patch introduces one possible (but not very serious and very rare) incompatibility: if one already uses explicitly defined negative-digit option such as '-1' and also uses an option with optional argument '-p [ARG]' and runs a command with options '-p -1' then before patch it'll be treated as two different options '-p', '-1' and after patch they are treated as an option '-p' with value '-1'.
If one meets this problem, he can use option declaration with equal sign: '-p=[ARG]' or just change places of arguments and run his program with options '-1 -p'.
But I suppose not too many people use explicitly defined numeric options and even less people use optional argument with them in such order (may be even nobody use it such a way).

Also, if possible, backporting into 1.9 of this patch will be very useful. Unfortunately I don't know how should I do this.

[zzak (zzak _)]

• File 259.patch 259.patch added

I've attached the patch from the associated pull request.

[prijutme4ty (Ilya Vorontsov)]

Any thoughts about this patch?

[jeremyevans0 (Jeremy Evans)]

• Status changed from Assigned to Closed

I don't think this is a bug, I think this is expected behavior. When parsing -p -1, where -p accepts an optional argument, OptionParser correctly treats the -1 as a new option, and raises an error as the parser does not accept that option. You have to specify the optional argument a different way to tell OptionParser that the -1 is the value for the optional argument. One way is -p-1, another is --pvalue=-1.