Route constraints regex with predefined characters classes in square brackets does not work

Looks like there is a bug in grammar for Regin regexp parser, because after we parse a regexp to expressions the "" symbol before "d" in regexp is lost. Gonna work on it tonight.

Oops. The \ symbol is lost. So [\d]+ becomes [d]+.

@Andrew White I think there is a bug in

expression = Regin.parse(regexp)

in Rack::Mount::Utits.parse_regexp

And i see generated files in rack/mouint/vendor/regin/regin but there is no grammar files, also in the beginning of the files:

#
# DO NOT MODIFY!!!!
# This file is automatically generated by Racc 1.4.6
# from Racc grammer file "".
#

So where can i get grammar files to find and fix a bug?

It seems to me that this is a HIGH priority issue.
The problem is with rack-mount using reign (as mentioned before) in Rails Router.

Running in Rails 3.0.1 console (JRuby 1.5.3)

jruby-1.5.3 > expression = Regin.parse(/\D[%-.\w]*/)
=> #

router.rb with the route definition

NCNAME = /\D[%-.\w]*/

match "/items/:item_id", :to => "items#index", :as => "item_base", :constraints => { :service_id => NCNAME }

Rails console tests:

jruby-1.5.3 > item_base_path('f')
=> "/items/f" jruby-1.5.3 > item_base_path('fee')
ActionController::RoutingError: No route matches {:controller=>"items", :item_id=>"fee"}

jruby-1.5.3 > item_base_path('f.......')
=> "/items/f......." jruby-1.5.3 > item_base_path('fwwww')
=> "/items/fwwww" jruby-1.5.3 > item_base_path('fww-----....%ww')
=> "/items/fww-----....%ww"

Running in Rails 3.0.1 console (JRuby 1.5.3)

jruby-1.5.3 > expression = Regin.parse(/\D[%-\.\w]*/) 
 => #<Expression "\\D[%-.w]*">

@2kan, https://github.com/josh/rack-mount/blob/master/Rakefile#L16 - may be this will be of assistance

Okay, sent a pull request to Josh. Once that's been applied and then the vendored regin in rack-mount is updated we can then look at bumping the rack-mount version.