From: "Matthew K. Williams" <matt@...>
Date: 2009-08-20T05:47:49+09:00
Subject: Re: #has_arguments?

On Thu, 20 Aug 2009, Joel VanderWerf wrote:

> Matthew K. Williams wrote:
>> As a followup, has_arguments? could be written as:
>> 
>> def has_arguments?(&b)
>>  vars = eval("local_variables",b.binding)
>>     return false if vars.length == 0
>>     vars.each do |v|
>>       return false if eval("#{v}.nil?",b)
>>     end
>>     return true
>>   end
>> end
>> 
>> 
>> then you'd call it like:
>> 
>> if has_arguments? {} #note the empty block
>>   something
>> end
>> 
>> 
>> Matt
>
> Using #local_variables won't work for this, will it?
>
> def has_arguments?(&b)
> vars = eval("local_variables",b.binding)
>  return false if vars.length == 0
>  vars.each do |v|
>    return false if eval("#{v}.nil?",b)
>  end
>  return true
> end
>
> def foo(*a)
>  if has_arguments? {} #note the empty block
>    p a
>  else
>    puts "no args"
>  end
>  x=3 # <-- N.B.
> end
>
> foo()
> foo(1,2,3)
>
> __END__
>
> Output:
>
> no args
> no args
>

Good point....  I didn't think of that case -- can you suggest a solution?