From: Michael Neumann <mneumann@...>
Date: 2003-05-19T18:41:49+09:00
Subject: Re: A recursive each method and a code block

On Mon, May 19, 2003 at 06:38:09PM +0900, Peter Hickman wrote:
> I have a simple search program that uses the each method with a yield to 
> pass back results as it finds it. However in depth first search the 
> method recurses at when it attempts the yield I get:
> 
> ./search.rb:82:in `each': no block given (LocalJumpError)
>         from ./search.rb:77:in `each'
>         from ./search.rb:77:in `each'
> 
> The code is:
> 
> class DepthFirstSearch < GeneralSearch
>   def each(list = @partials)

should be:

   def each(list = @partials, &block)

>     # Declaring this variable outside the loop speeds things up
>     temp = ''
> 
>     list.each {|p|
>       @nextitems.each {|n|
>         temp = [ p.map {|x|x}, n ].flatten
>         if is_valid(temp) then
>           if is_result(temp) then
>             @solutions += 1
>             yield temp
>           else
>             @checked += 1
>             each([temp])

each is called without block.
should be:
              each([temp], &block)



>           end
>         end
>       }
>     }
>   end
> end
> 
> I suspect the problem is, through various fiddling, that the code block 
> is not accessable to the subsequent recursion of the each method.
> 
> Any clues how to get this to work?

Regards,

  Michael