From: Eero Saynatkari <ruby-ml@...>
Date: 2006-01-18T13:44:54+09:00
Subject: Re: invalid_arity method similar to method missing ?

On 2006.01.18 11:40, Logan Capaldo wrote:
> 
> On Jan 17, 2006, at 8:30 PM, Didier Prophete wrote:
> 
> >The best I can do is get a handle to the 'method' object. Something
> >like:
> >  meth = self.method(:f1)
> >
> >But I am stuck there... I would need something like:
> >  meth.arg_list
> >which would return [ :arg1, :arg2 ], or something like that.
> 
> I don't believe there is a way to get the argument names from inside  
> ruby. 

Slightly off-topic, but there is :)

  def foo(a, b, c)
    local_variables.each {|var| puts "#{var}: #{eval var}"}
  end

  foo 1, 2, 3

> ... Can you define these methods (f1 and friends) to take a hash  
> instead?
> 
> eg:
> f1(:arg1 => 1, :arg2 => 2)
> 
> If you can't do this (you didn't write the functions) perhaps you  
> need a more robust abstraction, something like a class called  
> Invocation, or Call or something.
> 
> eg
> 
> class Call
>    attr_accessor :target, :method_name, :arguments
>    def argument_names
>         ... # insert code here to list the names of the arguments
>    end
> end
> 
> Of course you'll still need a way to generate this list. Perhaps with  
> RDoc. THis is a little complicated though, ideally you would simply  
> have the functions take a hash as its single parameter as I  
> mentioned. Still not quite sure what you are asking.


E