From: Dave Thomas <dave@...>
Date: 2008-03-15T22:56:29+09:00
Subject: Re: baffling undefined method error


On Mar 15, 2008, at 8:24 AM, Tom Cloyd wrote:

> I'm getting an error I can't account for. In a method I've written I  
> open a file and access a yaml store:
>
> archive_stored_list = 'archive_stored_list.yml'
> archives_stored_catalog = File.open(archive_stored_list) {|i|  
> YAML.load(i)}
>
> I massage the data a bit, and want to write it back out to the same  
> file. I try to close the file so I can open it for output, but get  
> an error:
>
> archives_stored_catalog.close # <= "undefined method `close'" error  
> is written to log file here
> open(archive_stored_list,"w")  {|i|  
> YAML.dump(archives_stored_catalog,i)}
>
> Why is this giving an error? Isn't the IO.close method always  
> available? Very confusing.


The block form of IO.open returns the value of the block. So, what is  
the class of archives_stored_catalog? It isn't an IO object. It's your  
loaded YAML data. So it doesn't have a close method.

Regards


Dave Thomas