From: Alexy Khrabrov <deliverable@...>
Date: 2007-10-25T22:35:52+09:00
Subject: Re: overcoming dynamic block evaluation

> On Oct 25, 2007, at 5:15 PM, Robert Klemme wrote:
> Unfortunately I don't have time to go through all of this, but did you
> consider to define a block with the default options like this?
>
> DEFAULT_OPTS = lambda do |opts|
>   opts.on("-v", "--[no-]verbose", "Run verbosely") do |v|
>     options.verbose = v
>   end
>   ...
> end
>
> ...
>
> opts = OptionParser.new do |opts|
>   DEFAULT_OPTS[opts]
>
>   opts.on("--type [TYPE]", [:text, :binary, :auto],
>                 "Select transfer type (text, binary, auto)") do |t|
>     options.transfer_type = t
>   end
>
> end

Well, I need to add textual reporting and report on all options, both  
set and unset.  By "default" options I mean not those common to all  
scripts, but those which are not mentioned explicitly on the command  
line, thus their blocks never get triggered.  So we cannot add  
reporting lines there as puts.  In my solution reporting lines are  
added to an enclosing unless <disabled> statement, and they are added  
to a list which is walked in the reporting loop later.

The question really is about overcoming the fact that the opt.on  
blocks are evaluated later and my initial trick of referring to  
options on a uniform way as o stumbles upon that deferred evaluation,  
when o was long redefined.

Cheers,
Alexy