From: matz@... (Yukihiro Matsumoto) Date: 2001-12-14T02:30:21+09:00 Subject: [ruby-talk:28435] Re: why is Proc's arity function so weird? Hi, In message "[ruby-talk:28422] why is Proc's arity function so weird?" on 01/12/14, Paul Brannan writes: |Why does arity return -1 when there is 1 argument? The problem with |this is the following: If you want to specify ONE argument you have to specify Proc.new{|a,|} not Proc.new{|a|} I agree this may against PoLS, but life is not that simple. This is the biggest shortage of Ruby. I will try to fix it in the future. matz.