From: dblack@...
Date: 2006-09-29T20:33:39+09:00
Subject: Re: New magical version of Symbol.to_proc

Hi --

On Fri, 29 Sep 2006, Dr Nic wrote:

>> My problem with something like this:
>>
>>    x.should.be.equal.to(y)
>>
>> It's very hard to know what "x.should.be" returns.  I can figure it
>> out, of course.  But it has a tone of "don't worry about what's
>> actually happening; just read the dot-connected words like a string",
>> which makes me uncomfortable.
>
> This would be readable assuming that "should" on x meant something. If I
> saw this I'd guess its like "assert".
>
> But, assuming that your list of words DID mean something, then it has to
> be more readable to newcomers (and yourself in 12 mths time) than the
> possible equivalent:

The intent is very clear, I think.  I just don't like the construct
:-)

> x.each {|an_x| assert_equal y, x}
>
> or to rephrase the example, perhaps:
>
> x.should {|an_x| an_x.be :equal, :to, y}

I think my example, in (say) TestUnit, would be more like:

   assert_equal(y,x)

But as I said, the magic dot example was made up, so I can't really
push the point of what it would be equal to in other terms.

> The magic dot gives you left-to-right readability, whereas the above
> makes you figure out whats happening in the closure first, then go back
> to the x.each part to see where an_x comes from.

I can't really comment without hooking my eyes up to a machine and
seeing where they go :-)  But there's no necessity to backtrack once
you've seen x.each {|an_x|, from the point of view of understanding
the code.  Mind you, the magic dot doesn't require backtracking
either.


David

-- 
                   David A. Black | dblack@wobblini.net
Author of "Ruby for Rails"   [1] | Ruby/Rails training & consultancy [3]
DABlog (DAB's Weblog)        [2] | Co-director, Ruby Central, Inc.   [4]
[1] http://www.manning.com/black | [3] http://www.rubypowerandlight.com
[2] http://dablog.rubypal.com    | [4] http://www.rubycentral.org