From: Jakub Travnik <j.travnik@...>
Date: 2001-12-14T05:26:40+09:00
Subject: [ruby-talk:28450] Re: why is Proc's arity function so weird?

Chr. Rippel wrote:

>>>From the Pickaxe book (online, since the printed version is wrong, as is
>>the online description of Proc#arity):
>>  Proc.new {||}.arity      �   0
>>  Proc.new {|a|}.arity     �  -1
>>  Proc.new {|a,b|}.arity   �   2
>>  Proc.new {|a,b,c|}.arity �   3
>>  Proc.new {|*a|}.arity    �  -1
>>  Proc.new {|a,*b|}.arity  �  -2
>>
> Add this to your list
> 
> Proc.new {||}.arity      �   0
> Proc.new {|a,|}.arity     �  1
> Proc.new {|a,b,|}.arity   �   2
> Proc.new {|a,b|}.arity   �   2
> Proc.new {|a,b,c,|}.arity �   3
> Proc.new {|a,b,c|}.arity �   3
> 
> .....
> Proc.new {|a|}.arity     �  -1
> Proc.new {|*a|}.arity     �  -1
> Proc.new {|a,*b|}.arity     �  -2
> Proc.new {|a,b,*c|}.arity     �  -3
> 
> /Christoph

and the most inconsistent imho is:

  Proc.new {}.arity  #=> -1

Why should Proc object take any number of arguments in call
when none of them are used?


Jakub Travnik
jabber://jtra@jabber.com